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Van Driesche et al.: Euonymus Scale Natural Enemies


RELEASE, ESTABLISHMENT AND SPREAD OF ASIAN
NATURAL ENEMIES OF EUONYMUS SCALE (HOMOPTERA:
DIASPIDIDAE) IN NEW ENGLAND

R. G. VAN DRIESCHE,' K. IDOINE,2 M. ROSE3 AND M. BRYAN4
1Department of Entomology, University of Massachusetts, Amherst, MA 01003

2Massachusetts Extension Service, Univ. of Massachusetts, Amherst, MA 01003

3Department of Entomology, Texas A&M University, College Station, TX 77843

4USDA APHIS, National Biological Control Laboratory, Niles, MI 49120


ABSTRACT

Between 1990 and 1995, the USDA/APHIS National Biological Control Labora
tory in Niles, MI, Texas A&M University, and the University of Massachusetts con
ducted a biological control introduction program against the Asian diaspidid scale
insect Unaspis euonymi (Comstock), a pest of woody landscape plants. Two species of
predators (Chilocorus kuwanae Silvestri, Coleop.: Coccinellidae and Cybocephalus sp.
nr. nipponicus Enrody-Younga, Coleop.: Cybocephalidae) and three aphelinid parasi
toids (Encarsia sp. nr. diaspidicola [Silvestri], Coccobius sp. nr. fulvus [Compere et
Annecke], and Aphytis sp.) were collected near F. 11-; China and released in south
ern New England. We report establishment of C. kuwanae, C. sp. nr. nipponicus and
Coccobius sp. nr. fulvus in Massachusetts. Chilocorus kuwanae has spread through
out southern New England and the proportion of euonymus shrubs in landscape-level
surveys bearing C. kuwanae stages was positively related to scale density, with the
coccinellid present on 1.1%, 6.3%, 12.5%, and 26.3% of shrubs whose scale populations
were classified as none, light, medium, and heavy, among 4843 plants examined from
1992-1994 in Massachusetts, Connecticut, and Rhode Island. Cybocephalus sp. nr.
nipponicus and C. sp. nr. fulvus, while established at some release sites, have been ob
served to spread to new locations in only one and two instances, respectively. Encarsia
sp. nr. diaspidicola was recovered at some release locations, but establishment is un
certain. No recoveries were made of the Aphytis sp. parasitoid, but this species was re
leased later than the other species and further recovery efforts are needed.

Key Words: Chilocorus kuwanae, Cybocephalus sp. nr. nipponicus, Coccobius sp. nr.
fulvus, biological control, establishment

RESUME

Entre 1990 y 1995 el Laboratorio Nacional de Control Biol6gico del USDA/APHIS
en Niles, Michigan, la Universidad de Texas A&M, y la Universidad de Massachusetts
dirigieron un program de control biol6gico de introducci6n en contra de la escama
asiatica Unaspis euonymi (Comstock) (Diaspididae), una plaga que ataca arbustos le
nosos utilizados en arreglos de jardineria. Dos species de depredadores (Chilocorus
kuwanae Silvestri, Coleop.: Coccinellidae y Cybocephalus sp. nr. nipponicus Endrody
Younga, Coleop.: Cybocephalidae) y tres parasitoides de Hymenoptera: Aphelinidae
(Encarsia sp. nr. diaspidicola (Silvestri), Coccobius sp. nr. fulvus (Compere et An
necke), y Aphytis sp.), fueron colectados cerca de F. lI-1 China, y liberados en el sur
de New England. Reportamos el establecimiento de C. kuwanae, C. sp. nr. nipponicus
y Coccobius sp. nr. fulvus en Massachusetts. Chilocorus kuwanae se ha extendido por
todo el sur de New England; las proporciones de arbustos de euonymus muestreados

















Florida Entomologist 81(1)


en jardines con estadios de C kuwanae resultaron estar relacionados estadistica
mente en forma positive con la densidad de la escama, con la presencia de la coccinela
en 1.1%, 6.3%, 12.5%, y 26.3% de los arbustos con poblaciones de escamas clasificadas
como nula, ligera, median, y fuerte en 4,843 plants examinadas en 1992-1994 en
Massachusetts, Connecticut, y Rhode Island. Cybocephalus sp. nr. nipponicus y C. sp.
nr. fulvus, aunque se establecieron en algunos sitios donde se realizaron liberaciones,
han sido observados en otros sitios en solo una y dos ocasiones respectivamente. En-
carsia sp. nr. diaspidicola fue recolectada en varias localidades donde liberaciones fue
ron realizadas, pero su establecimiento no esta confirmado. Recolectas del parasitoide
Aphytis sp. no se han logrado, pero como esta especie fue liberada mas tarde que las
otras species, es necesario que se realicen mas esfuerzos de recolecci6n en el future.





Euonymus scale, Unaspis euonymi (Comstock), is an exotic diaspidid scale of
Asian origin that feeds on foliage and stems of woody landscape plants in the United
States. In New England, the species overwinters as mated adult females, and eggs are
produced in the spring. Three generations occur yearly. Major host plants are species
of Euonymus, many of which were imported from Asia (Flint 1983) and are widely
planted in urban areas (Gill et al. 1982). Effective natural enemies of euonymus scale
were not present in North America before 1980, when USDA and state cooperating
entomologists began the importation of predators and parasitoids from Korea (Drea
& Hendrickson 1988, Hendrickson et al. 1991). From 1991-1994, collections of euony
mus scale were made in the vicinity of F1. ,,-1 China and sent to M. Rose at Texas
A&M University for quarantine and initiation of natural enemy cultures. Five species
of scale natural enemies were recovered and released in New England: Chilocorus ku
wanae Silvestri (Coleop.: Coccinellidae), Cybocephalus sp. nr. nipponicus Endrody
Younga (Coleop.: Cybocephalidae), two internal parasitoids, Coccobius sp. nr. fulvus
(Compere et Annecke), Encarsia sp. nr. diaspidicola (Silvestri), and an external par
asitoid, Aphytis sp. (all, Hymenoptera: Aphelinidae).
Chilocorus kuwanae is a multivoltine coccinellid that feeds on high density popu
lations of various species of diaspidid scales (Nohara & Iwata 1989, Bull et al. 1993).
Cybocephalus sp. nr. nipponicus is a much smaller predator that oviposits under indi
vidual scales, with the larva feeding sequentially on a small number of scales over the
course of its development (Alvarez et al. in press). Of the three aphelinid parasitoids,
only one, Coccobius sp. nr. fulvus, has received previous study. An internal parasitoid,
this species parasitizes adult female scales, both before and after development of scale
eggs (Takagi 1991).
Chilocorus kuwanae and C. sp. nr. nipponicus from Korea were established in the
northeastern United States earlier (Drea & Carlson 1987, 1988). We report further re
leases of these predators in New England, releases of three species of parasitoids, es
tablishment of C. kuwanae, C. sp. nr. nipponicus, and C. sp. nr. fulvus in
Massachusetts, and estimates of rates of occurrence of Chilocorus kuwanae in south
ern New England on landscape euonymus plants in relation to scale density.


MATERIALS AND METHODS


Collection and Laboratory Rearing

In 1990, adult Chilocorus kuwanae feeding on euonymus scale on Euonymus spp.
near F 1J,11 China were collected and shipped to the USDA/ARS quarantine facility


March, 1998

















Van Driesche et al.: Euonymus Scale Natural Enemies


in Newark, DE, where the coccinellid was identified and bred for one generation prior
to release from quarantine. This colony was then used to make releases in southern
New England starting in 1991.
Each year from 1991 1994, 3-5 shipments of Euonymus sp. branches infested with
euonymus scale were sent by collectors in China to a quarantine laboratory at Texas
A&M University Collections were made in various locations within 200 km oi I- 1i-
by Mr. Shen Zhicheng (1991), Mr. Du Yongjun (1992, 1993) and Mr. Zhao Youfou
(1994). In each year, collections were made in late April-early May of overwintered
adult female scales and then again in summer and early fall. In this manner, different
life stages of scale predominated in different collections, allowing opportunity to en
counter parasitoids associated with various life stages.
Four of the five species of natural enemies obtained could be reared under labor
tory conditions on San Jose scale (Quadraspidiotus perniciosus [Comstock]) and field
collected stock was used to initiate laboratory cultures on this alternate host. Both
parasitoids emerging from field-collected scales and from laboratory rearing were
used for field releases, except for C sp. nr. fulvus which could only be reared on eu
onymus scale. All C. sp. nr. fulvus released were adults that emerged from immatures
collected in China.
In addition to the euonymus scale natural enemies obtained from China, two spe
cies of natural enemies (C. kuwanae and C. sp. nr. nipponicus) originally collected in
Korea were also obtained from USDA entomologists from earlier sites of establish
ment in the Washington, D.C. area. Releases of these predators were made in Massa
chusetts in 1988 and 1989. Subsequent collection of these same natural enemies in
China was intended to find populations of these agents from areas more climatically
similar to southern New England, as well as to locate new agents.


Field Releases

Releases were made in Massachusetts, Connecticut, and Rhode Island on Euony
mus fortune (Turz.) Hand.-Mazz. and Euonymus europaeus L. plants infested with
medium to heavy populations of euonymus scale in urban or suburban locations from
1991 to 1995. Releases of C. kuwanae included adults, older larvae, and pupae. Mobile
stages were allowed to crawl from opened 0.5 liter cardboard containers placed in eu
onymus plants. All other agents were released as adults by fixing open vials or cups
containing parasitoids or C. sp. nr. nipponicus onto infested shrubs and allowing
adults to walk or fly out.


Assessment of Establishment

For C. kuwanae, establishment was confirmed by visual inspection of shrubs at re
lease sites to detect larvae, pupae, or adults, which were readily observed. Chilocorus
adults were identified to species by examination of the pronotal punctation pattern to
separate the released species from the native species Chilocorus stigma Say, which
was occasionally encountered feeding on euonymus scale (Drea & Carlson 1987). Fif
teen release sites (three each in western, central and eastern Massachusetts, Con
necticut and Rhode Island) were visited every three weeks for 1-3 years, depending on
survival of the shrub at each site, and the number of C. kuwanae life stages (larvae,
pupae, adults) seen in three 5-min counts was recorded as an index of coccinellid pop
ulation increase.
For C. sp. nr. nipponicus, establishment was confirmed by recovery of adult speci
mens, relying primarily on detection of males, which have a beige head and pronotum

















Florida Entomologist 81(1)


and black body, and their comparison to voucher specimens. At some locations, estab
lishment of C. sp. nr. nipponicus was detected by holding scale-infested twigs in card
board cartons for three weeks and later noting the presence of adults or pupae in the
rearing container.
Establishment of released parasitoid species was assessed by either rearing or dis
section. Rearing of scales was done by holding cut twigs in 0.5 liter cardboard contain
ers with ventilated tops at 21-27C for three weeks. Material in the bottom of the
rearing containers was then examined for dead adult parasitoids. Parasitoids were
identified by comparison with voucher specimens.
In 1994, dissection of fully developed third stage female scale insects from 18 loca
tions in Massachusetts was used to detect immature parasitoids. Samples were col
elected every three weeks from April through October. Larval and egg stages of
Encarsia sp. nr. diaspidicola could not be separated from those of Aspidiotiphagus sp.,
a preexisting euonymus scale parasitoid in the United States that was common in
southern New England, and therefore dissection was not useful in detecting this spe
cies. However, larvae of Coccobius sp. nr. fulvus were distinctively longer and more
thread-like than larvae of either Aspidiotiphagus sp. or Encarsia sp. nr. diapsidicola,
and could be reliably recognized. Pupae of Coccobius sp. nr. fulvus were black in con
trast to the yellow-brown or striped pupae of Encarsia sp. nr. diaspidicola and Aspid
iotiphagus sp. Pupal exuviae of Coccobius sp. nr. fulvus were completely black and
easily distinguished from those of the other parasitoids. Therefore, C. sp. nr. fulvus
could be reliably detected in samples from release sites by finding their larvae, pupae,
or pupal exuviae. Rates of parasitism of the preexisting parasitoid Aspidiotiphagus
sp. in these samples were also recorded and are reported to provide comparisons to fu
ture samples after introduced parasitoids have had sufficient time to reach their max
imal levels of impact. Voucher specimens of all five natural enemies have been
deposited in the insect collection of the U.S. Natural History Museum.


Rates of C. kuwanae Presence on Landscape Plants

To determine how widespread C. kuwanae had become following its establish
ment, a total of 4843 euonymus plants were examined in surveys conducted in Mas
sachusetts, Connecticut, and Rhode Island from 1992 to 1994. Landscape euonymus
plants (E. fortune and E. europaeus) were located throughout each state. In Massa
chusetts, where three quarters of all surveyed plants were located, surveys were con
ducted yearly in an average of 54 towns in eleven counties. Each shrub was classified
by scale infestation level category and the presence or absence of C. kuwanae life
stages in 2 minute inspection periods was noted. Scale infestation categories were as
follows: none-close inspection fails to reveal any scales; light-the shrub from one
meter away appears uninfested but close inspection of the undersides of leaves re
veals the presence of scattered second stage male scales (the most abundant, easily
visible stage); medium-the shrub is visibly infested in casual inspection, but scales
do not encrust stems, nor is die back of limbs present; and heavy-scales encrust stems
and foliage and are immediately visible from a distance, die back of limbs is common.


Statistical Analysis

Chi square tests were performed on data to determine relationships between pres
ence of C. kuwanae beetles and scale infestation levels on shrubs; and, for other data,
to determine the relationship between the presence of the parasitoid Aspidiotiphagus
sp. and scale infestation levels on shrubs (Daniel 1987). Simple linear regression was


March, 1998

















Van Driesche et al.: Euonymus Scale Natural Enemies


used to assess the relationship between the post-release counts of the number of C
kuwanae and numbers released at sites to determine if numbers of beetles released or
differences in site features were more important to C. kuwanae population growth.


RESULTS


Releases

In 1988 and 1989, 400 adults of a Korean population of C. kuwanae were released
in Massachusetts at 15 sites. In 1991 and 1992, 2535 adults, larvae, or pupae of Chi
nese C. kuwanae were released at 25 sites in southern New England (Massachusetts,
Connecticut, or Rhode Island). From 1991 to 1993, 675 adults of C sp. nr. nipponicus
from Korea and 945 from China were released at 17 sites in southern New England
(Fig. Ib). From 1991 to 1994, 3862 adults of C. sp. nr. fulvus were released at 11 sites
in Hampshire and Franklin Counties in Massachusetts (Fig. Ic, map shows towns
used for releases; some towns had several release sites). From 1993 to 1995, a total of
12,966 adults of E. sp. nr. diaspidicola were released at 27 sites in eight counties in
Massachusetts and one county in Connecticut (Fig. Id). In 1994 and 1995, 801 adults
of Aphytis sp. were released at five sites in two Massachusetts counties (Fig. le).


Establishments

Chilocorus kuwanae (Chinese strain) established at most release sites, but popu
nation increase at sites varied greatly. Of 15 sites followed in detail, the beetle estab
lished at all 15, following release of various numbers. Peak numbers of C. kuwanae
life stages counted per five minute observation varied from 5 or fewer at three sites
where the beetle scarcely persisted, to over 50 at five sites where beetle increased sub
stantially. No relationship was observed in simple linear regression between numbers
released per site and subsequent peak counts of beetles (R2 0.002, Y 30.37 +
0.007X, with X and Y as in Fig. 2), suggesting that site factors other than initial re
lease rate were primarily responsible for beetle success at individual sites (Fig. 2).
Cybocephalus sp. nr. nipponicus was encountered at five of the seventeen release
sites in the year following release, indicating successful establishment. Same-season
reproduction of the beetle was observed at ten other sites (Fig. Ib).
Coccobius sp. nr. fulvus was recovered in 1994 from six of eleven release sites (from
releases in either 1992 or 1993), indicating establishment (six sites, but only four
towns, Fig. Ic). Same-season reproduction was observed at one additional location. Of
155 wasps obtained in rearing samples, 109 (70%) were female.
Encarsia sp. nr. diaspidicola was recovered in 1994 from two of ten 1993 release
sites. Same-season reproduction was observed in 1993 or 1994 at twelve other sites
(Fig. Id-note, some locations marked on the distribution map include several sites).
Establishment of this species remains uncertain.
Aphytis sp. releases were made later than those of other species. Recovery efforts
in 1995, the last year of the study were unsuccessful and the status of this species is
unknown.


Spread of Released Species

Of the five species released, C. kuwanae has achieved the most extensive range in
southern New England (Fig. la). In 1992-1994 surveys of randomly selected land
















Florida Entomologist 81(1)


Chilocorus kuwanae Cybocephalus nr. nipponicus


Cocobius sp. nr. fulvus Encarsia nr. diaspidicola


Aphytis sp.

Fig. 1. Distribution in southern New England of Chilocorus kuwanae Silvestri (a);
Cybocephalus sp. nr. nipponicus Enrody-Younga (b); Coccobius sp. nr. fulvus (Compere
et Annecke) (c); Encarsia sp. nr. diaspidicola (Silvestri) (d); Aphytis sp. (e); open circles
(releases with no recoveries), half filled circles with strike through lines (releases with
recoveries, in the same year only) and filled circles (releases with recoveries one or
more years after release).



scape euonymus plants in southern New England, the beetle was found on 14.1% of
3141 shrubs that were infested with euonymus scale, out of a total of 4843 plants ex
amined. The proportion of shrubs with C. kuwanae present increased significantly
with increasing scale density (Fig. 3) (df = 3, (2 = 516.6).
Spread of other released species of natural enemies was rarely observed. One case
of recovery at a nonrelease site was noted for C. sp. nr. nipponicus and two for C. sp.
nr. fulvus.


March, 1998

















Van Driesche et al.: Euonymus Scale Natural Enemies


sq p





0O





0


0 100 200 300 400


500 600


Number of C. kuwanae Released per Site

Fig. 2. Relationship between number of Chilocorus kuwanae Silvestri released at
a site and the peak number of the coccinellid counted per five minutes subsequently
at the same location, over the course of 1-3 years of observations every three weeks
(April through October) (R2 0.002, where Y = 30.37 + 0.007X).


Occurrence of Nonreleased Parasitoid Species

Aspidiotiphagus sp. was a preexisting aphelinid found parasitizing euonymus
scale at 44% of 79 sites in southern New England from which euonymus scales were
collected and reared in 1991 (Table 1). The presence of the parasitoid was not signifi
cantly related to the level of the scale infestation at a site (df = 2, 2 5.991). Parasit
ism of third stage female euonymus scales, pooled by generation, for scales dissected
in 1994 from 18 locations in Massachusetts was 13.4% (n = 2174 scales) for the over
wintered spring adults, 33.6% (n= 1271 scales) for the summer generation, and 31.2%
(n = 933 scales) in the fall generation.

DISCUSSION

The coccinellid C. kuwanae is now widespread throughout southern New England
on euonymus scale plants infested with euonymus scale. Establishment of C. kuwa
nae at release sites was not related to numbers released. Likely influences were host
density, bush size and degree of sunniness at sites. The later two factors were not,
however, quantified. Coccinellids were recovered at sites ranging from shrubs at cool,
moist sites surrounded by lawn, to hot, dry sites such as shrubs at shopping malls,
where plants were often surrounded by concrete and bark mulch. Most sites examined
were urban or suburban in nature and no attempt was made to assess rates of discov
ery by coccinellids of shrubs at isolated properties in non-urban areas. Rates of recov
ery of C. kuwanae on shrubs examined in the statewide surveys of euonymus scale
were unlikely to have been influenced by proximity to release sites because release
sites were few (45 over a five year period) and the number of shrubs in surveys was


40


30


20

















Florida Entomologist 81(1)


20


15


10


None


Light


Medium


Heavy


Euonymus Scale Infestation Level

Fig. 3. Percentages (and SE values) of euonymus plants in various categories of
scale density on which Chilocorus kuwanae Silvestri was present in surveys in south
ern New England in 1992-1994, where sample sizes by category were 1702 (N), 1401
(L), 745 (M), and 995 (H), and divided by state were 3220 (Massachusetts), 1076 (Con
necticut), and 547 (Rhode Island).


large (4843) and shrubs were distributed widely over the three state area. Thus, while
a few sites may by chance have been close (under 5 km) to release sites, most were not.
Chilocorus kuwanae life stages were most commonly encountered on plants with
medium or heavy scale infestations, suggesting that the principal effect of this coc
cinellid will be to suppress scales at sites where scale densities are at or approaching
damaging levels, rather than acting when scale densities are light. Because Cyboce
phalus sp. nr. nipponicus and Coccobius. sp. nr. fulvus require fewer hosts for repro


TABLE 1. PRESENCE OF ASPIDIOTIPHAGUS SP. ON EUONYMUS PLANTS WITH DIFFERENT
EUONYMUS SCALE DENSITIES IN SOUTHERN NEW ENGLAND IN 1991.

Samples Samples
Scale Inf. Level with Aspidiotiphagus without Aspidiotiphagus

light 7 (64%)' 4
medium 7 (35%) 13
heavy 21 (44%) 27

total 35 (44%) 44

"Percentage samples with parasitoids was not significantly associated with scale density in a x2 test (df = 2,
x = 5.991).


March, 1998

















Van Driesche et al.: Euonymus Scale Natural Enemies


duction, these species may be more effective in causing mortality to low density scale
populations. Establishment of these agents in Massachusetts makes possible a future
evaluation of their effects on survivorship of scales in low density populations. The re
maining parasitoids (E. sp. nr. diapidicola and Aphytis sp.) have not yet been shown
to have established; future assessment of their status will be needed.


ACKNOWLEDGMENT

We thank the USDA/APHIS National Biological Control Laboratory, Niles, MI, for
financial support for this project; Narda Wakoluk, Aaron Hechmer, Stephen Healey,
Jim Oldham and Don Wilda for technical assistance; R. S. Stauffer for quarantine ac-
tivities at Texas A&M University; and the owners of the sites where the work was con
ducted for the use of their property.


REFERENCES CITED

ALVAREZ, J. M., AND R. G. VAN DRIESCHE. Biology of Cybocephalus sp. nr. nipponicus
(Coleoptera: Cybocephalidae), a natural enemy of euonymus scale, Unaspis eu-
onymi (Homoptera: Diaspididae). Environ. Entomol. in press.
BULL, B. C., M. J. RAUPP, M. R. HARDIN, AND C. S. SADOF. 1993. Suitability of five hor
ticulturally important armored scale insects as hosts for an exotic predaceous
lady beetle. J. Environ. Hort. 11: 28-30.
DANIEL, W. W 1987. Biostatistics: A Foundation for Analysis in The Health Sciences.
J. Wiley & Sons, New York. 734 pp.
DREA, J. J., AND R. W. CARLSON. 1987. The establishment of Chilocorus kuwanae (Co
leoptera: Coccinellidae) in eastern United States. Proc. Entomol. Soc. Washing
ton 89: 821-824.
DREA, J. J., AND R. W. CARLSON. 1988. Establishment of Cybocephalus sp. (Co
leoptera: Nitidulidae) from Korea on Unaspis euonymi (Homoptera: Diaspid
idae) in the eastern United States. Proc. Entomol. Soc. Washington 90: 307-309.
DREA, J. J., AND R. M. HENDRICKSON, JR. 1988. Exotic predators. American Nursery
man 168(8): 66-71.
FLINT, H. 1983. Landscape Plants for Eastern North America, Exclusive of Florida
and the Immediate Gulf Coast. John Wiley & Sons, New York. 677 pp.
GILL, S. A., D. R. MILLER, AND J. A. DAVIDSON. 1982. Bionomics and taxonomy of the
euonymus scale, Unaspis euonymi (Comstock), and detailed biological informa
tion on the scale in Maryland. Univ. Maryland Agric. Exp. Sta. Misc. Pub., No.
969, 36 pp.
HENDRICKSON, R. M., JR., J. J. DREA, AND M. ROSE. 1991. A distribution and estab
lishment program for Chilocorus kuwanae (Silvestri) (Coleoptera: Coccinel
lidae) in the United States. Proc. Entomol. Soc. Washington 93: 197-200.
NOHARA, K., AND M. IWATA. 1988. Studies on ovipositing behavior of Chilocorus ku
wanae Silvestri (Coleoptera: Coccinellidae). Proceedings of Faculty of Agricul
ture, Kyushu Tokai University 7: 17-24 (in Japanese).
TAKAGI, M. 1991. Host stage selection in Aphytis yanonensis DeBach et Rosen and
Coccobius fulvus (Compere et Annecke) (Hymenoptera: Aphelinidiae), intro
duced parasitoids of Unaspis yanonensis (Kuwana) (Homoptera: Diaspididae).
Appl. Ent. Zool. 26: 505-513.

















Florida Entomologist 81(1)


A NEW SPECIES OF MYODOCHA (HEMIPTERA: LYGAEIDAE:
RHYPAROCHROMINAE: MYODOCHINI) FROM THE WEST
INDIES

ALEX SLATER
801 Alabama Street, Lawrence, KS 66044

ABSTRACT

Myodocha froeschneri n. sp. is described based on specimens from Dominican Re
public, Haiti, and Jamaica.

Key Words: West Indies, Myodocha, new species

RESUME

Se describe Myodocha froeschneri n. sp. basada en especimenes de la Republica
Dominicana, Haiti, y Jamaica.





The genus Myodocha is characterized by elongate body and appendages. The head
is especially elongate with the postocular region produced into a narrow stalk-like
neck. The seven previously described species are primarily Neotropical with one spe
cies, M. serripes Olivier, broadly distributed in the Nearctic. M froeschneri, named for
Dr. Richard Froeschner of the United States National Museum, is described in ad
vance of a revision of the genus to make the name available for a faunal work on the
West Indies by R. M. Baranowski and J. A. Slater.

Myodocha froeschneri A. Slater, New Species

Structure.-Head: vertex evenly convex, shiny, with obscure, barely perceptible
texturing; juga rounded, not carinate, nearly glabrous, no hairs longer than least di
ameter of neck; ocelli just behind line connecting hind margins of compound eyes; lat
eral margin behind eye evenly rounded to neck. Labium: segment I not surpassing
posterior margin of compound eye; II not reaching prosternum; IV reaching, not sur
passing, fore coxa. Pronotum: dull; collar and anterior lobe impunctate; posterior lobe
shallowly punctate, punctures ranging from contiguous to separated by twice puncture
diameter. Scutellum: dull; sparsely, obscurely punctate; indistinct Y shaped median ca
rina. Thoracic sterna: dull dark brown except mesosternum shiny. Hemelytra: not
reaching apex of abdomen. Legs: shiny; fore femur lightly incrassate, hairs short,
sparse, spines in two ranks restricted to about apical third, three small spines in ante
rior rank, two small and one large (basal) spine in posterior rank; fore tibia unarmed.
Measurements.-All in mm. Total length 9.0. Head: length 2.6, preocular 0.7, pos
tocular including neck 1.4, width across eyes 1.2, interocular 0.6. Antennal segment
length: I 1.1, II 2.1, III 1.9, IV 2.3. Labial segment length: I 1.0, II 1.2, III 1.1, IV 0.5.
Pronotum: length collar plus anterior lobe 0.8, posterior lobe 0.7, greatest width an
terior lobe 1.1, posterior lobe 1.7. Scutellum: length 0.9, width 0.7. Hemelytra: length
corium 3.5, claval commissure 0.8, membrane 2.8 (to corial apex 1.6, beyond corial
apex 1.2).


March, 1998

















A. Slater: New Species ofMyodocha


Color.-Head dark reddish brown becoming darker ventrally, clypeus lightest,
neck darkest. Antennal segment I reddish brown, II creamy white, III creamy white
except apical third pale brown, IV creamy white except basal seventh and apical third
pale brown. Pronotum dark brown fading to dark reddish brown on apical half poste
rior lobe. Scutellum dark brown. Corium dark brown except extreme base, extreme
apex, basal half costal margin, claval margin, two small elongate discal spots level
with middle of clavus, large subapical spot from costal margin almost to membranal
margin, and indistinct discal spot opposite basal angle of membrane off white. Clavus
dark brown; veins lightest, subbasal and larger subapical spot darkest. Membrane
dark brown, veins subbasally and indistinct elongate apical spot lighter, off white op
posite corial apex. Coxae dark brown; femora light reddish brown except pale basally;
tibiae pale brownish yellow, tarsi yet paler brownish yellow. Abdomen reddish brown,
segments V VIII becoming darker apically, lateral margin segment V and basal half
lateral margin segment VI off white.
Types: Holotype male. HAITI: Enneri, nr. 1000 ft., Sept. 6-11-34, Darlington. De
posited in the American Museum of Natural History. Paratypes. HAITI: 1 female, En
neri, no date, Mann; 1 female, Etang Lachaux, S. W. Peninsula (sic), under 1000 ft.,
Oct. 26-27, 1934, Darlington. DOMINICAN REPUBLIC: 1 male, S.R. [San Rafael ?],
4 km. S.W Stgo Rodriguez, May 28, 1978, C. W. & L. B. Obrien & Marshall; 1 male,
Barahona, 9.2 km N.W Paraiso, confluence of Rio Nizso and Rio Coltico, 18-03N, 71
12W, 230 m., 9-10 Aug 1990, J. Rawlins, S. Thompson; 1 male, La Vega, 1.5 km. N Jar
bacoa, 240 m., 21 July 1987, J. Rawlins, R. Davidson. JAMAICA: 1 female, St. An
drews, 9/17 and JA20, at light, A. M. Richie; 1 female, Balaclava, 15 April 1909, A. S.
Wright; 1 female, same data but 1 May 1909. In collections of the American Museum
of Natural History, Carnegie Museum, Snow Entomological Museum, British Mu
seum (Natural History), J. A. Slater.
Variation.-The holotype male is fairly light in overall color. The darkest speci
mens examined are almost uniformly dark chocolate brown on head and body except
for the pale areas on abdominal segments V and VI. On these darker specimens the
light areas on clavus and corium are more distinct except the discal dorial spots and
the light areas on the membrane except at the corial apex are obscured. The color pat
tern of legs and antennae remains constant except that the darker areas are more dis
tinct and antennal segment II becomes pale reddish brown apically. The femoral
spines range from 3-5 in the anterior rank and from 2 to 4 in the posterior rank. Three
spines in each rank is most common. In only one case is a short spine located basal of
the long basal spine of the posterior rank. In one case the posterior rank bears 2 about
equally long basal spines. Total length varies from 8.0-9.0 mm in males and from 9.0
9.6 mm in female.
Etymology.Named for Dr. Richard C. Froeschner, United States National Mu
seum.
Identification: The combination of smooth head vertex and lack of elongate hairs
on the "neck" separate M. froeschneri from all other members of the genus except the
Cuban M. fulvosa Barber. That species is castaneous or fulvous in color, has unicol
ored fore femora, and typically has at least one small spine basal to the long subapical
spine.


REFERENCES CITED

HARRINGTON, B. J. 1980. A generic level revision and cladistic analysis of the Myodo
chini of the world (Hemiptera, Lygaeidae, Rhyparochrominae). Bull. Amer.
Mus. Nat. Hist. 167(2): 45-116.

















Florida Entomologist 81(1)


DISTRIBUTION AND DISPERSAL OF CACTOBLASTIS
CACTORUM(LEPIDOPTERA: PYRALIDAE), AN EXOTIC
OPUNTIA-FEEDING MOTH, IN FLORIDA

DEREK M. JOHNSON' AND PETER D. STILING
Department of Biological Sciences, University of South Florida, Tampa, FL 33620

'Current Address: Department of Biology, University of Miami
Coral Gables, FL 33124

ABSTRACT

The recent arrival of Cactoblastis cactorum Berg in Florida has raised concern for
Florida's native Opuntia cacti. Moreover, the potential for movement of the moth
across the gulf states and into the southwestern United States may endanger cacti in
the Opuntia-rich areas of Texas, Arizona, New Mexico, and Mexico. However, the
spread of the moth northward through Florida has either slowed since the invasion or
the rate of spread for the first two years was over estimated. The mortality rate of
pads and the distribution of egg sticks at six sites in Florida were recorded on 0.
stricta Haworth, the most common host in Florida. While the percentage of cactus
pads with C cactorum damage is as high as 60%, the data indicates that most mature
cacti are not being reduced in size. However, small cacti and new growth pads are par
ticularly susceptible to mortality by C cactorum, thus, over time we may expect to see
a reduction in the number of plants as a result of an increase in the mortality rate of
recruits.

Key Words: pest, biological control, herbivory, moth, cactus

RESUME

La reciente introducci6n a la Florida de Cactoblastis cactorum Berg a causado pre
ocupaci6n en cuanto a los cactos indigenas de la Florida de la especie Opuntia. Ade
mas, la posibilidad de que la palomilla advance a trav6s de los estados del Golfo hacia
el suroeste de los Estados Unidos amenaza areas con abundancia de Opuntia en
Texas, Arizona, Nuevo Mexico, y Mexico. Sin embargo, la expansion de la palomilla
hacia el norte a traves de Florida desde que la invasion empez6 ha disminuido o el cal-
culo de la tasa de expansion durante los dos primeros anos fui exagerado. La tasa de
la mortalidad de las pencas de cacto y la distribuci6n de grupos de huevos en seis lo
calidades en Florida fueron registrados en 0. stricta Haworth, que es el hospedero
mas comfn dentro de Florida. Aunque el porcentaje observado de pencas danadas por
C cactorum es tan alto como el 60%, los datos indican que los cactos mas maduros no
estan siendo reducidos en tamano. Sin embargo, cactos pequenos y pencas nuevas son
particularmente susceptibles a mortalidad causada por C cactorum; en consecuencia,
en un future podriamos contar con una reducci6n del numero de plants debido al au
mento de la tasa de mortalidad de cactos j6venes.





In 1957, the moth Cactoblastis cactorum Berg was introduced onto the Caribbean
island of Nevis as a biological control agent for pest Opuntia spp. and in 1960 was in
produced onto Montserrat and Antigua (Simmonds & Bennett, 1966). The moth dis
persed to other islands such as Cuba, Puerto Rico, Hispaniola, the Bahamas, and
Cuba (Habeck & Bennett, 1990).


March, 1998

















Johnson & Stiling: Cactoblastis cactorum distribution


A Florida Keys record for C cactorum in October, 1989, was a new record for the
continental United States (Habeck & Bennett, 1990). The moth likely arrived in Flor
ida by one of two methods: (1) natural dispersal via flight/wind from the Caribbean or
(2) via shipments of cacti to Miami from the Caribbean (Pemberton, 1995). This spe
cies may disperse beyond Florida, and eventually reach the Opuntia-rich desert
southwest. The moth successfully dispersed several times from one island to another
in the Caribbean; thus, spread across long distances is possible. The moth may have
already invaded the Yucatan (Pemberton, 1995), thus, the moth also may disperse to
the southwestern United States via Mexico.
Florida has six species of native Opuntia (0. stricta Haworth, 0. humifusa
(Rafinesque) Rafinesque, O. spinosissima (Martyn) Miller, 0. triacantha (Willdenow)
Sweet, 0. cubensis Britton & Rose, and 0. pusilla (Haworth) Haworth) (Benson,
1982). Cactoblastis cactorum has been found on all of the natives except 0. pusilla
(Bob Ehrig, The Nature Conservancy, pers. comm.; pers. obs.). The United States
ranges of three of these cacti, O. spinosissima, 0. triacantha, and 0. cubensis, are lim
ited to local populations in the Florida Keys. Only 12 0. spinosissima plants remain
in one location in the Florida Keys and 0. triacantha and 0. cubensis are rare.
This study focuses on the attack of C. cactorum on 0. stricta. 0. stricta is a common
cactus throughout coastal Florida, growing in sandy soils and shell mounds. We inves
tigated the rate of the moth's spread throughout Florida, distribution of egg sticks and
larval damage, and extent of damage to 0. stricta. This information, coupled with the
information from oviposition and larval choice experiments (Johnson & Stiling, 1996),
could be useful in setting future management goals for C. cactorum in the continental
United States.


MATERIALS AND METHODS


Damage and Egg Stick Distribution

We repeatedly visited ten sites throughout south and central Florida (Fig. 1). Upon
each visit to every site, we counted the total number of cactus pads on 20 to 100 0.
stricta plants, the number of pads with old C. cactorum damage (those that had been
fed upon but the larvae had since abandoned them), the number of pads with new lar
val damage (pads with larvae currently feeding on them), and the number of egg
sticks per plant. The same population of plants was surveyed at every census. From
October, 1991 to November, 1992, each site was sampled approximately monthly The
sites were sampled less frequently in 1993.
We are confident that the vast majority, if not all, of old damage, new damage, and
egg sticks measured at the eight sites were attributable to C cactorum and not the na
tive cactus-feeding moth, Melitera prodenialis Walker, for the following reasons. First,
at all sites where C cactorum larvae were not detected, the percentage of pads with
old damage was less than one percent, while within a year after C cactorum larvae
were detected, old damage increased to over ten percent. Secondly, cactus pads with
new damage were randomly cut open and the larvae were identified. All Pyralidae lar
vae encountered at the sites were C. cactorum. Lastly, the widths of C cactorum egg
sticks are narrower than M. prodenialis egg sticks and the ranges of width are non
overlapping (DMJ, unpublished data). Three-hundred eighty-two hatched egg sticks
were collected from the sites and compared to egg sticks known to be laid by C. cac
torum and M. prodenialis. All of the egg sticks were determined to be laid by C. cac
torum. Thus, while we can not be certain that M. prodenialis was always absent, we
are confident that its contribution was insignificant.

















Florida Entomologist 81(1)


Fig. 1. Opuntia stricta populations surveyed for Cactoblastis cactorum from Octo
ber 1991 to October 1993.


The distribution of egg sticks on cacti was measured by using the Morisita Index
of Dispersion (Krebs, 1989). The Kruskal-Wallis test (Sokel & Rohlf 1981) was used to
determine whether the number of egg sticks on a plant and the number of egg sticks
per pad was related to plant size (as measured by the total number of pads). The
Kruskal-Wallis test was also used to determine whether the percent damage was re
lated to the size of the plant.
In addition, all reports of C. cactorum detected in new locations around Florida
were examined to determine when the moth extended its known range northward
along both the east and west coastlines. These reports included personal observations,
reports to the Florida Department of Agriculture and Consumer Services (FDACS),
and other sources.

Growth and Mortality of Opuntia stricta

From January to March 1992 all individual pads on 10 0. stricta plants at the Wal
ton Rocks Beach site were marked. In 1993 10 additional plants were marked. Each
pad was numbered using permanent ink. Upon every subsequent visit, once per


March, 1998

















Johnson & Stiling: Cactoblastis cactorum distribution


month in 1992 and less frequently in 1993, pad mortality and the number of new
growth pads were recorded. These data were used to determine net growth of the at
tacked plants. The Rank Sum Test (Ambrose & Ambrose 1987) was used to determine
whether smaller cacti had a significantly higher mortality The Wilcoxon Signed
Ranks Test (Sokel & Rohlf 1981) was used to determine whether new pads suffered a
higher mortality caused by C. cactorum than did old pads.

RESULTS

Damage and Egg Stick Distribution

Peaks in new larval damage and percentage of pads with egg sticks varied tempo
rally and spatially (Figs. 2 and 4). No C. cactorum was recorded at Lover's Key or
Rookery Bay Larval activity was generally highest from May to September, but larval
activity also heightened in late fall and early winter of 1991 at most sites. Larval dam
age measurements, the percentage of pads with both old and new damage, increased
at every site from the fall of 1991 to the fall of 1992. Overall, measurements of damage
decreased slightly from the fall of 1992 to the fall of 1993 at all of the sites except
Ocean Bluff, Terra Ceia and Brevard #2. Over the 2 year period, the percentage of
dead or damaged pads increased (range 9-37%) at all 6 sites (Fig. 3). Percent damage
and plant size were not significantly related (p > 0.05).
Egg sticks were clumped among plants (Table 1). At two of the six sites tested, sig
nificantly more egg sticks were laid on either medium or large-sized plants (Table 1).
At the other four sites with a sufficient number of egg sticks the trend was present but
not significant. The number of egg sticks per pad was not significantly different be
tween small, medium, and large plants at any of the sites (p > 0.10) (Table 1).
At the peak of old C. cactorum damage, 90% of the plants with over 10 pads had
old damage (Table 2). Excluding plants at the Terra Ceia site, which had a lower per
centage of old damage than the other sites, 172 out of 173 plants (99.4%) with over 10
pads showed evidence of previous larval damage as compared to 14 of 28 plants (50%)
with 10 pads or fewer having previous larval damage.

The Spread of Cactoblastis cactorum

The spread of C. cactorum up Florida's east coast, assuming that the moth first col
onized the lower Florida Keys and migrated north, has been relatively well docu
mented as compared to Florida's west coast. The moth was first discovered in the
United States on Big Pine Key in October, 1989 (Habeck & Bennett, 1990). In less
than a year, the moth was discovered at Key Biscayne State Park in Miami (FDACS,
unpublished), approximately 200 km east northeast of Big Pine Key. One year later,
in August, 1991, the moth was discovered at Brevard #1 (FDACS, unpublished), ap
proximately 240 km north of Key Biscayne. The most northerly record of C. cactorum
was at Brevard #2 (Patrick Air Force Base), 50 km north of Brevard #1 (pers. obs.). The
moth arrived at this site in June 1992 and has established there.
The spread of C. cactorum up the west coast of Florida has not been so well docu
mented. The first west coast record was in Terra Ceia, Manatee County, in May 1991
(FDACS, unpublished), one year and seven months after its discovery in the Florida
Keys and approximately 360 km north. Six months later, the moth was discovered at
Fort Desoto State Park in Pinellas County (pers. obs.), approximately 16 km north of
Terra Ceia. The most northerly record of C. cactorum on the west coast of Florida was
at Upper Tampa Bay Park in Hillsborough County, February, 1992 (pers. obs.). This
site is approximately 50 km north of Fort Desoto.



















16 Florida Entomologist 81(1) March, 1998


10
S -- Brevard #2
6
~ ~ ~ --- __---------------



Oct-91 Jan-92 Apr-92 Jul-92 Oct-92 Jan-93 Apr-93 Jul-93 Oct-93 Jan-94
10

o
8 -9 Brevafd #1

0 4k



10
Ot-91 Jan-92 Apr-92 Jul-92 Oct-92 Jan-93 Apr-93 Jul-93 Oct-93 Jan-94
10
S- --Watton Rocks Beach




4
Oct-91 Jan-92 Apr-92 Jul-92 Oct-92 Jan-93 Apr-93 Jul-93 Oct-93 Jan-94
10

S- Briny Breezeso


4
21

Oct-91 Jan-92 Apr-92 Jul-92 Oci-92 Jan-93 Apr-93 Jul-93 Oct-93 Jan-94
10
I --m- Fort Desoto






--i- Terra Cela
6







4




S10
Oct-91 Jan-92 Apr-92 Jul-92 Oct-92 Jan-93 Apr-93 Jul-93 Oct-93 Jan-94




10
S- -i-- OTerra Cea



i ~)LongKey



4
2
zo
Oct-91 Jan-92 Apr-92 Jul-92 Oct-92 Jan-93 Apr-93 Jul-93 Oct-93 Jan-94






Oct-91 Jan-92 Apr-92 Jul-92 Ocl-92 Jan-93 Apr-93 lul-93 Oct-93 Jan-9


Fig. 2. Percentage of Opuntia stricta pads with new damage due to Cactoblastis
cactorum larval feeding at eight sites in central and south Florida (see Fig. 1 for loca
tions).



















Johnson & Stiling: Cactoblastis cactorum distribution 17



S60 -- Brevard#2
40
20 -
S20
o 0 _-******.- --,. -- 9-- a= -- ,- s,
Oct-91 Jan-92 Apr-92 Jul-92 Oct-92 Jan-93 Apr-93 Jul-93 Oct-93 Jan-94
80
60 -u- Brevard #1
40
2 20

Oct-91 Jan-92 Apr-92 Jul-92 Ocl-92 Jan-93 Apr-93 Jul-93 Oct-93 Jan-94
80
60 -s- Watton Rocks Beach
40
20 -
0
Ocl-91 Jan-92 Apr-92 Jul-92 Oct-92 Jan-93 Apr-93 Jul-93 Oct-93 Jan-94


60 -t- Briny Breezes
84
3 20 -
0
Oct-91 Jan-92 Apr-92 Jul-92 Oct-92 Jan-93 Apr-93 Jul-93 Oct-93 Jan-94
80
60 --- Fort Desoto
(3 40
20
40
Oct-91 Jan-92 Apr-92 Jul-92 Oct-92 Jan-93 Apr-93 Jul-93 Ocl-93 Jan-94
80
| 60 -- Terra Ceia
S40
M 20


Oct-91 Jan-92 Apr-92 Jul-92 Oct-92 Jan-93 Apr-93 Jul-93 Oct-93 Jan-94
80
60 -a- Long Key

40
60

Oct-91 Jan-92 Apr-92 Jul-92 Oct-92 Jan-93 Apr-93 Jul-93 Oct-93 Jan-94
90
60 --w- Ocean Bluff -

20

Ovl-91 Jan-92 Apr-92 Jul-92 Oct-92 Jan-93 Apr-93 Jul-93 Oct-93 Jan-94


Fig. 3. Percentage of Opuntia stricta pads with old damage due to Cactoblastis cac
torum larval feeding at eight sites in central and south Florida (see Fig. 1 for loca
tions).



















18 Florida Entomologist 81(1) March, 1998


2

0 |----_----- --------.---------_--- .---_-_---------
1.5 -~-- Brevard #2
v-


0.0
Oct-91 Jan-92 Apr-92 Jul-92 Oct-92 Jan-93 Apr-93 Jul-93 Oct-93 Jan-94
2
1.5 --Brevard #1
04


Oct-91 Jan-92 Apr-92 Jul-92 Oct-92 Jan-93 Apr-93 Jul-93 Oct-93 Jan-94


S1.5 -g- Walton Rocks Beach

05

Oct-91 Jan-92 Apr-92 Jul-92 Oct-92 Jmn-93 Apr-93 Jul-93 Oci-93 Jan-94
2 (4.38)-
s1.5 -- Briny Breezes


0.5
1 -

Oct-91 Jan-92 Apr-92 Jul-92 Oct-92 Jan-93 Apr-93 Ju-93 Oct-93 Jan-94
2 13.06)
S1.5 - Fort Desoto
-a
0.5
0
Oct-91 Jan-92 Apr-92 Jul-92 Oct-92 Jan-93 Apr-93 Jul-93 Oct-93 Jan-94
2 (241)
S1.5 -- Terra Ceia
1

0
Oct-91 Jan-92 Apr-92 Jul-92 Oct-92 Jan-93 Apr-93 Jul-93 Oct-93 Jan-94


1.5 ,-I- Long Key




Ocl-91 Jan-92 Apr-92 Jul-92 Oct-92 Jan-93 Apr-93 Jul-93 Oct-93 Jan-94

Sl5. -- Ocean Bluff


-I 05 -

Oct-91 Jan-92 Apr-92 Jul-92 Oct-92 Jan-93 Apr-93 Jut-93 Oct-93 Jan-94

Fig. 4. Percentage of Opuntia stricta pads with Cactoblastis cactorum egg sticks at
eight sites in central and south Florida (see Fig. 1 for locations).

















Johnson & Stiling: Cactoblastis cactorum distribution


TABLE 1. CACTOBLASTIS CACTORUMEGG STICK DISTRIBUTIONS ON SIX POPULATIONS OF
OPUNTIA STRICTA.

Egg Stick Distribution

Among Plant Size Egg Sticks per Pad by
Site Plants" By Plant Sizeb Preferred Plant Sizeb

Ocean Bluff Clumped N. S. N. S.
Long Key Clumped Signif., p < 0.05 Medium N. S.
Briny Breezes Clumped N. S. N. S.
Walton Rocks
Beach Clumped N. S. N. S.
Terra Ceia Clumped Signif., p < 0.01 Large N. S.
Fort DeSoto Clumped N. S. N. S.

Tested using the Morisita index of dispersion (significant at p < 0.05).
bTested using the Kruskal-Wallis test (significant at p < 0.05).


There has been almost no confirmed records of inland movement of over a few of
kilometers by C. cactorum in Florida. The discovery of the moth in Loxahatchee, Palm
County in June of 1992 (FDACS, unpublished), 24 km inland from the Atlantic Ocean,
is the most inland of confirmed records.


Growth and Mortality of Opuntia stricta

Growth in nine plants marked in 1992 ranged from a loss of 100% of the pads to
an increase of 87%. One of the 10 plants marked in 1992 was not located until 1 year
later. Some of the marks had worn off of the pads, so this plant was omitted from anal
ysis. Two of the nine plants died from larval feeding during 1992. These were two of
the three smallest marked plants (each having nine pads). The net growth of all of the
plants in 1992 was +5%.
During the second year of monitoring, plant growth ranged from 100% to +56%.
The net mean growth of all of the plants was +6%. The smallest of the original nine
plants, having eight pads, was the only plant in this group to die (killed by C. cac
torum) during 1993. Thus, over the two year period the three smallest plants died.
Plants with nine or fewer pads had a higher mortality rate than plants with greater
than nine pads (Rank Sum Test; p < 0.05).
The 10 plants that were marked and monitored in 1993 had a much higher growth
rate. Only 1 of the 10 plants decreased in number of pads (27%) and the highest
growth rate was +170%. The mean net growth of the 10 plants was +86%. In 1992 and
1993 combined, new growth pads sustained a higher mortality rate due to larval dam
age than did old growth pads on 22 out of 25 plants (Wilcoxon Signed Ranks Test; n
25, p < 0.05) (Fig. 5).


DISCUSSION

Cactoblastis cactorum in Florida is more active in the spring and summer. The dis
tribution and spread of the moth largely has been restricted to the coastal regions of
south and central Florida. The lack of inland reports of the moth may be because 0.

















Florida Entomologist 81(1)


TABLE 2. RELATIONSHIP BETWEEN THE SIZE OF OPUNTIA STRICTA AND DAMAGE BY CAC
TOBLASTIS CACTORUM.

Size of plant

Site Damage 0-10 pads 11 more pads

Ocean Bluff Present 3 39
Absent 1 0
Long Key Present 2 18
Absent 6 0
Briny Breezes Present 2 24
Absent 4 0
Walton Rocks Beach Present 6 61
Absent 2 1
Terra Ceia Present 6 42
Absent 30 22
Fort Desoto Present 1 33
Absent 1 0
Total Present 20 217
Absent 44 23

Percentage of plants with damaged
pads 31% 90%


stricta is more common in coastal areas (Benson 1982) or because of other biotic and
abiotic factors. Future work should address why C. cactorum's distribution is mainly
coastal so we can determine whether it will, in time, invade inland populations of
Opuntia.
Previous studies in Australia and South Africa found that the females lay their egg
sticks in a clumped distribution based on plant size, plant color, and shelter from the
wind (Myers et al., 1981; Robertson, 1987). Similarly, egg sticks were clumped at all
of our sites and more were laid on medium or large-sized plants at two of the sites.
There was no difference, however, in the number of egg sticks per pad among plants
of different sizes. Thus, pads on large plants are no more likely to have egg sticks laid
on them than pads on small plants. This is consistent with our finding that there is no
relationship between C. cactorum damage and plant size.
The moth is doing significant damage to 0. stricta individuals in Florida, but is the
moth reducing the populations? Overall, the number of pads on marked individual
cacti at Walton Rocks Beach increased in 1992 and 1993. However, while fewer small
plants received moth damage than did medium or large-sized plants, small cacti with
moth damage were most susceptible to mortality. Thus, C. cactorum could strongly re
duce the survivorship of maturing 0. stricta. We may reach a scenario in Florida
whereby large 0. stricta can withstand the attack, but, in the ensuing years, as these
plants die, there are fewer individuals to replace them. Only then would the total ad
verse effect of C. cactorum become noticeable. Forecasting such a process necessitates
a more detailed study in which recruitment as well as the fates of the plants are mea
sured. Also, 0. stricta populations in Australia partially recovered a few years after


March, 1998
















Johnson & Stiling: Cactoblastis cactorum distribution


2 3 4 5 6 7 8 9
1992


40 -


20 -


Mated in J Ismay 1992


j~1FI H1


1 2 3 4 5 6 7 8 9
1993



Mted inJAuML 1993


10 11 12 13 14 15
1993
Plant Number


16 17 IR


Fig. 5. Percent mortality of old growth vs. new growth pads on marked Opuntia
stricta in 1992 and 1993.


the introduction of C. cactorum, only to be decimated greater within the next few
years (Dodd 1940).
Soon after C. cactorum was discovered in Florida, its rapid invasion northward
prompted concern not only for native Florida cacti but for those native to the rest of
the North American continent (especially the Opuntia-rich desert southwest). The
movement of the moth northward through Florida from 1989 to 1991, assuming it dis
persed from the lower Florida Keys, averaged over 160 miles per year. From 1991 to


TT~-

















Florida Entomologist 81(1)


1993, however, the spread averaged only 24 miles per year. Recent information (Pem
berton, 1995) indicates that C. cactorum may have invaded Florida via imported cacti
through Miami rather than natural dispersal, in which case the dispersal rate re
ported for 1989 to 1991 is an over estimate. Determining the true rate of spread of C.
cactorum and which biotic and/or abiotic factors affect this rate, would be valuable be
cause then we could determine if and when the moth may be expected to attack Opun
tia in other regions of North America (barring accidental introduction on imported
cacti).


ACKNOWLEDGEMENTS

The authors thank The Nature Conservancy for providing the opportunity to be a
part of this conservation effort. R. Ehrig was of great assistance in locating field sites
and discussing the goals of the project. Thanks to A. Rossi for his invaluable advise
concerning experimental design and statistical analysis. We are grateful to E. McCoy
and H. Mushinsky for reviewing an earlier version of this manuscript. Thanks to D.
Gordon, R. Pemberton, D. Habeck, and three anonymous reviewers for reviewing this
manuscript. D. Jones was of great service in solving graphical dilemmas. Funding was
provided by the Missouri Botanical Garden and The Garden Club of America through
the Catherine H. Beattie Fellowship. Additional funding was provided by The Nature
Conservancy and the United States Department of Fish and Wildlife.


ERFERENCES CITED

AMBROSE, H. W., III, AND K. P. AMBROSE. 1987. A Handbook of Biological Investiga
tion. Fourth Edition. Hunter Textbooks Inc. Winston-Salem, NC.
BENSON, L. 1982. The Cacti of the United States and Canada, Stanford University
Press: Stanford, CA. 1044 pp.
DODD, A. P. 1940. The biological campaign against prickly pear, Commonwealth
Prickly Pear Board: Brisbane. 177 pp.
HABECK, D. H., AND F. D. BENNETT. 1990. Cactoblastis cactorum Berg (Lepidoptera:
Pyralidae), a phycitine new to Florida. Fla. Dept. Agric. & Consumer Serv. Di
vision of Plant Industries, Entomology Circular 333.
JOHNSON, D. M., AND P. D. STILING. 1996. Host specificity of Cactoblastis cactorum
Berg, an exotic Opuntia-feeding moth, in Florida. Environmental Entomology,
25(4), 743-748.
KREBS, C. J. 1989. Ecological Methodology. Harper Collins Publishers, Inc., NY.
MYERS, J. H., J. MONRO, AND N. MURRAY. 1981. Egg clumping, host plant selection
and population regulation in Cactoblastis cactorum (Lepidoptera). Oecologia
(Berlin), 51, 7-13.
PEMBERTON, R. W. 1995. Cactoblastis cactorum: An immigrant or introduction?
American Entomologist, 41: 230-232.
ROBERTSON, H. G. 1987. Oviposition site selection in Cactoblastis cactorum (Lepi
doptera): constraints and compromises. Oecologia (Berlin), 73, 601-608.
SIMMONDS, F. J., AND F. D. BENNETT. 1966. Biological control of Opuntia spp. by Cac
toblastis cactorum in the Leeward Islands (West Indies). Entomophaga, 11(2),
183-189.
SOKAL, R. R., AND F. J. ROHLF. 1981. Biometry, Freeman, San Francisco.


March, 1998

















Cruz & Martinez: Effect of Male Secretions on Females 23

EFFECT OF MALE MESADENE SECRETIONS ON FEMALES OF
CANTHON CYANELLUS CYANELLUS (COLEOPTERA:
SCARABAEIDAE)

MAGDALENA CRUZ R. AND IMELDA MARTINEZ M.
Institute de Ecologia, A.C., Depto. Ecologia y Comportamiento Animal
Apartado Postal 63, 91000 Xalapa,Ver. Mexico

ABSTRACT

This study determined the effect of male mesadene secretions on females of Can
thon cyanellus cyanellus LECONTE, both when they were inseminated normally and
when the secretions were transplanted to virgin females. In the first case, mating took
place when the ovary was immature, triggering ovarian maturation, egg laying and
nest building. In the second case, the transplantation of male mesadene secretions to
virgin females initiated ovarian maturation, but neither egg laying nor nest building
took place. Virgin females that did not receive the secretions had no ovarian matura
tion and did not lay eggs or build nests. It is therefore possible that male mesadene
secretions induce ovarian maturation. In the present study, this inducement was
greater in inseminated females than in those receiving transplanted secretions.

Key Words: Mesadene secretions, Transplant, Ovarian maturation, Scarabaeinae

RESUME

En este trabajo se determine el efecto que tienen las secreciones de las mesadenias
del macho sobre las hembras de Canthon cyanellus cyanellus, cuando son insemina
das normalmente, o cuando las secreciones son trasplantadas a hembras virgenes. En
el primer caso la copula tuvo lugar cuando el ovario estaba inmaduro, desencade
nando la maduracidn ovarica, la oviposicidn y la construccidn del nido. En el segundo
caso, el trasplante de las secreciones de las mesadenias a hembras virgenes inicid la
maduracidn ovarica, pero no la oviposicidn ni la construccidn del nido. Las hembras
virgenes que no recibieron las secreciones no maduraron el ovario ni hubo oviposicidn
o construccidn del nido. Es possible que las secreciones mesad6nicas del macho induz
can la maduraci6n ovarica. Esta inducci6n fue mayor en las hembras inseminadas que
en las que recibieron el trasplante de las secreciones.





In various species of Scarabaeinae (Scarabaeidae), mating takes place shortly af
ter the female emerges (Monteith & Storey 1981; Klemperer 1982) or before egg lay
ing (Halffter & L6pez 1977; Halffter et al. 1980; Huerta et al. 1981; Monteith & Storey
1981; Anduaga & Huerta 1983; Sato & Hiramatsu 1993). In the above-mentioned
cases, mating is necessary for egg laying and nesting to begin.
In the dung beetles, Canthon indigaceus chevrolati HAROLD and Copris incertus
SAY, the first mating, which occurs during the pre-nesting period, when the ovary is
still immature, is indispensable for ovarian maturation, egg laying and nesting to oc
cur (Martinez & Cruz 1990; Martinez et al. 1996).
In Canthon cyanellus cyanellus LECONTE, the first mating is at 10 days after fe
male emergence. This occurs half way through the pre-nesting period, which lasts
about 20 days. During this period ovarian maturation occurs, only food balls are pro

















Florida Entomologist 81(1)


duced and there is no nesting. Afterwards, during the nesting period, other matings
may occur (Martinez 1992).
During mating, the male of C. c cyanellus produces a spermatophore containing
abundant seminal fluid which consists principally of the secretions of the accessory
glands (mesadenes). Most of this seminal fluid has a high concentration of proteins,
although it also contains glycogen and acid mucopolysaccharides (Cruz & Martinez
1992). This is also the case in other Coleoptera (Anderson 1950; Landa 1960; Gerber,
et al. 1971; Gundevia & Ramamurty 1977; Huignard et al. 1977; Peferoen & de Loof
1983; Black & Happ 1985).
The objective of this study was to determine the effect of male mesadene secretions
in C. c. cyanellus upon ovarian maturation and female reproductive behavior.



MATERIALS AND METHODS

This study was carried out on adult Canthon cyanellus cyanellus, of known age
and raised in the laboratory. Insects were kept at 27'C, 70% RH, a photoperiod of
14:10 hours and were fed beef.
Females were tested in one of four manners: 1) a female was kept together with a
male from the time of emergence (n = 63), 2) virgin females were isolated from the
time of emergence (n = 57), 3) virgin females received transplants of mesadene secre
tions from mature males at 10 days old (n = 31), and 4) virgin females had sterile
Ringer-Ephrussi solution injected at 10 days old (n = 25).
The females in categories 1 and 2 were sacrificed at 5, 10, 15, 20, and 25 days of
age, with approximately 10 females per age group. At 10 days of age the females in
categories 3 and 4 received the secretion transplant or the injection of Ringer solution.
It was allowed to take effect for 5, 10 or 15 days. The females in these last two catego
ries were sacrificed at 15, 20 and 25 days of age. The were about 5 females in these age
groups.
To carry out mesadene transplantation, the reservoir, a structure in which glan
dular secretions are stored, was obtained from 20-30 day-old males. Females were an
aesthetized with ethyl acetate for 3 minutes, which allowed them to recover without
complications. The elytra and wings of anaesthetized females were lifted carefully,
and the reservoir was placed in the dorsal region of the abdomen. Using an entomo
logical pin, a dorsal puncture was made through which glandular secretions were in
produced into the abdominal cavity. It was not necessary to use sealer, as the wound
healed quickly on its own. Females recovered in about 5-10 minutes. After a 24-hours
period they were put inside a terrarium (Cruz 1994).
The reproductive systems from all four groups were dissected out in Ringer
Ephrussi solution. Each ovary was measured and drawn to scale with the aid of a
camera lucida. The ovary and vaginal frotis together with the spermatheca from each
female were obtained and dyed in toto using the Feulgen-green light technique. The
presence of the spermatophore in the vagina or of spermatozoids in the spermatheca
indicated that the female had been inseminated.
The length of the basal oocyte was analyzed in each age group and the different
categories were compared. Sample sizes were 5 to 17 females per age group. Since
these were small samples, a 95% confidence interval was calculated using the formula
x + a 1//n (1.96), where x is the sampling median and aR, is the standard deviation.
Analysis of variance (ANOVA) was used to compare means.
Female reproductive behavior was categorized according to the following factors:
if they were inseminated, if they laid eggs, and either made food or nest balls.


March, 1998


















Cruz & Martinez: Effect of Male Secretions on Females 25

RESULTS

The female reproductive system in C. cyanellus cyanellus is similar to that of other
Scarabaeinae: it consists of a single left ovary with one ovariole, an oviduct, vagina
and spermatheca with its accessory gland.


Females with Males

In these females, the first basal oocyte measured 0.7 mm 5 days after eclosion. By
the 10th day it had more than doubled in size to 1.5 mm. By the 15th day it had again
doubled in size. After 20 days, it was almost egg-laying size, which in this species is 3
mm (Fig. 1; Table 1). Females in this group copulated between 10 and 15 days of age.
Spermatozoids were observed in the spermatheca, and the spermatophore was in the
vagina. By 15 days after eclosion, all of the females dissected had been inseminated
but had not yet begun to nest. By 20 days, most of the females had already laid a first
egg, and the second basal oocyte was close to egg-laying size. At the age of 25 days, all
females were making their first nest with 1 to 7 nest balls, corresponding at 1 to 7 eggs
laid.




4-1


3.5-


3-


2.5-
rc


S 2-




1-




0.5-


"---4r


5 10 15 20 25 30 40 50

age (days)

Fig. 1. First basal oocyte development in Canthon cyanellus cyanellus females. (X)
Females with male since emergence, the arrow shows the age at which first copula oc
curs; (*)Virgin females; (+) Virgin females with transplant from 10 days of age on; (D)
Virgin females injected with Ringer's solution.


,.*

















Florida Entomologist 81(1)


TABLE 1. BASAL OOCYTE MATURATION IN FEMALES OF CANTHON CYANELLUS CYANEL
LUS KEPT WITH A MALE SINCE EMERGENCE (F-M), VIRGIN FEMALES (VF), VIR
GIN FEMALES WITH TRANSPLANT (VF-T) AND VIRGIN FEMALES INJECTED WITH
RINGER'S SOLUTION (VF-R). (X SE)(N) NUMBER OF FEMALES PER AGE.

Basal oocyte length (mm)
Age
(days) F-M VF VF-T VF-R

5 0.72 0.10(10) 0.61 0.17(11)
10 1.50+ 0.12(14) 1.52+ 0.15(12)
mating
15 2.50+0.15(17) 1.51 0.09(12) 1.68+0.15(10) 1.13+0.17(10)
20 3.58 +0.10(10) 1.16 0.10(10) 1.60+0.13(10) 1.180.08(10)
25 2.65 +0.21(12) 1.10+ 0.10(12) 2.08 0.17(11) 1.26 0.31(5)


Virgin Females

Until the 10th day, the development of the first basal oocyte in these females was
similar to that of females of the same age that had been kept with males. On the 15th
day, the size of the basal oocyte remained almost identical to that observed at 10 days.
From day 20 to 25, however, it gradually diminished in size, and was reabsorbed in fe
males more than 50 days old (Fig. 1: Table 1).
The ovaries of virgin females did not fully mature, and the oocytes entered into re
absorption. Virgin females only made food balls, and did not construct nest balls or
nest.

Virgin Females with Male Mesadene Secretion Transplant

The transplant of secretions was performed at 10 days of age due to our observa
tion that the first mating tends to occur around this age. At day 15 the first basal oo
cyte measured an average approximately 1.6 mm; this size did not change by 20 days
of age. However, at 25 days of age, the first basal oocyte became substantially larger
(Fig. 1; Table 1). All females in this group initiated first basal oocyte maturation, but
oocytes did not reach egg-laying size even at 25 days.
Although they initiated ovary maturation, these females did not lay eggs, make
nest balls or nest; their only activity was the production of food balls.

Virgin Females Injected with Ringer's Solution

In these females, first basal oocyte size did not noticeably increase (Fig. 1; Table 1);
furthermore, neither egg laying, ovary maturation or nest making took place. Activity
was limited to making food balls which they did not turn into nest balls.


DISCUSSION

In Canthon cyanellus cyanellus the development of the first basal oocyte in virgins
was compared with those of females kept together with the male since the time of
emergence. After 15 days, the size of the first basal oocyte was no longer comparable


March, 1998

















Cruz & Martinez: Effect of Male Secretions on Females 27

between the two groups (F1,2,: 26.8; p < 0.01). In females which were inseminated by
a male, the ovary was bigger than in individuals kept alone. This difference was great
est at 20 days of age (F1,,1,: 210; p < 0.01) even compared to 25-day-old females (F11,22,:
41.8;p < 0.01).
These results demonstrate that the first mating triggers the final maturation of
the basal oocyte and the ovary, and, in some yet unknown way, induces egg laying and
nesting. This has also been demonstrated to be true in Canthon indigaceus chevrolati
and Copris incertus. In these two beetles, virgin females neither finish ovary matura
tion, lay eggs, nor make nests (Martinez & Cruz 1990; Martinez et al. 1996).
A comparison of the size of the first basal oocyte in females which were inseminated
and in those which received male mesadene transplant showed marked differences
from the age of 15 days (F,1,2,,: 14.0; p < 0.01) until 20 days (F,,1,,,:136; p < 0.01), but dif
ferences were non significant at 25 days (F,1,21 : 4.1); the effects of mating and glandular
secretions are, therefore, not comparable. The slow increase in basal oocyte size in fe
males that received the transplant suggests that egg laying size could be reached at a
more advanced age, although this was never confirmed through observation.
When virgin females were compared with those that received the transplant of
male mesadene secretions, it became clear that the secretions do have a positive effect
on ovarian maturation. After 20 days of age, the basal oocyte size was larger in the fe
males receiving the transplant than in virgins (F, ,,,: 6.4; p < 0.05). The greatest dif
ference was observed during the period between 20 and 25 days of age (F,1,21,: 24.6; p <
0.01): the ovary continued to mature up to an advanced stage, but oviposition did not
take place during the period of observation. In females over 30 days old, basal oocyte
size diminished in unaltered virgins but not in those that had received the secretion
transplant.
An analysis of females with the transplant compared to those with Ringer's solu
tion injections at various ages yielded the following data: the only significant differ
ence observed was between treatments (F.1,41: 14.4; p < 0.05) regardless of age (F4,50 :
1.4; non significant). Virgin females which received male mesadene transplants had
greater oocyte size than virgin females injected only with Ringer's solution.
When C. c. ... 11...: ,, -1. females received the transplant of male mesadene se
cretions, the ovary matured up to an advanced stage, but oviposition never took place.
Females can receive the stimulus that induces ovarian maturation either during cop
ulation or through the transplant of secretions. We do not yet know which of the com-
ponents in these secretions act directly upon the ovary to induce vitellogenesis and
ovary maturation, but the abundance of certain proteins may indicate that they are
responsible.
In the weevil Acanthoscelides obtectus SAY (Huignard 1984) and in the mosquito
Aedes taeniorhyncus (WIEDEMANN) (Borovsky 1985), vitellogenesis is induced by
proteins called paragonial substances found in secretions of the male glands. In A. ob
tectus these substances are distributed through the haemolymph to the female's head,
thorax and abdomen soon after mating and induce ovarian maturation (Huignard
1978). In other species of flies, and a grasshopper in which virgin females received se
cretions or male accessory gland extracts, ovarian maturation and egg laying resulted
(Merle 1968; Leahy 1973; Burnet et al. 1973; Ramalingan & Craig 1976). Egg laying
in various species of Orthoptera is also controlled by the paragonial substances (Pick
ford et al. 1969; Leahy 1973; Friedel & Gillott 1976) and in one butterfly (Santhosh
Babu & Prabhu 1987). In various species of Diptera, these substances control not only
oviposition but the sexual receptiveness of females after mating (Burnet et al. 1973;
Baumann 1974; Ramalingan & Craig 1976; Young & Downe 1987; Ohashi et al. 1991;
Spencer et al. 1992).

















Florida Entomologist 81(1)


In various species of insects, after lysis of the spermatophore into the vagina, the
spermatozoids and part of the seminal fluid pass into the spermatheca. The remain
der of the seminal fluid enters the haemolymph, where it subsequently reaches target
sites directly or via a hormone that controls reproductive output (Raabe 1986).
Although it has been confirmed that the first mating is necessary for ovarian mat
duration and egg laying in Canthon indigaceus chevrolati, Copris incertus and Canthon
c. cyanellus, only in C. c. cyanellus has it been show that the male mesadene secretions
induce ovarian maturation and egg laying. However, in the dung beetle genus Sisy
phus LATREILLE, virgin females sometimes make a few brood balls that contain in
fertile eggs or no eggs at all (Paschalidis 1974), suggesting that in this group the male
mesadene secretions is not necessary to induce ovarian maturation and egg laying.

ACKNOWLEDGMENTS

This study was carried out with the support of Account No. 902-38 of the Instituto
de Ecologia, A. C. Xalapa, Veracruz (Mexico). We thank at Dr. W D. Edmonds for the
revision of the manuscript in English, at two anonymous reviewers and the editor of
this journal for their sound commentary


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ANDUAGA, S., AND C. HUERTA. 1983. Factores que inducen la reabsorci6n ovarica en
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BAUMANN, H. 1974. Biological effects of paragonial substances PS, and PS2 in females
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BLACK, P. N., AND G. M. HAPP. 1985. Isolation, partial characterization, and localiza
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BOROVSKY, D. 1985. The role of the male accessory gland fluid in stimulating vitello
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BURNET, B., K. CONNOLLY, M. KEARNEY, AND R. COOK. 1973. Effects of male parago
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CRUZ, R. M. 1993. Actividadh reproductora de los machos de Canthon indigaceus che
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HALFFTER, G., V. HALFFTER, AND C. HUERTA. 1980. Copula and nesting behavior of
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HALFFTER, G., AND Y. LOPEZ. 1977. Development of the ovary and copula behavior in
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HUIGNARD, J. 1978. Transfert de secretions males du spermatophore vers l'h6mo
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HUIGNARD, J. 1984. Transfert, importance physiologuique et sp6cificit6 des secretions
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HUIGNARD, J., A. QUESNEAU-THIERRY, AND M. BARBIER 1977. Isolement, action bio
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PICKFORD, R., A. B. EWEN, AND C. GILLOTT. 1969. Male accessory gland substance: an
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RAMALINGAN, S., AND G. B. CRAIG. 1976. Functions of the male accessory gland secre
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30 Florida Entomologist 81(1) March, 1998

SATO, H., AND K. HIRAMATSU. 1993. Copula behaviour and sexual selection in the af
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239.

















Florida Entomologist 81(1)


NATURAL PARASITISM OF PHYLLOCNISTIS CITRELLA
(LEPIDOPTERA:GRACILLARIIDAE) AT CUITLAHUAC,
VERACRUZ, MEXICO

NESTOR BAUTISTA-MARTINEZ', JOSE LUIS CARRILLO-SANCHEZ',
HIRAM BRAVO-MOJICA' AND STEPHEN D. KOCH2
'Instituto de Fitosanidad, Colegio de Postgraduados, 56230 Montecillo
Estado de Mexico, Mexico

Institute de Recursos-Naturales, Colegio de Postgraduados, 56230 Montecillo
Estado de Mexico, Mexico

ABSTRACT

The Citrus Leafminer Phyllocnistis citrella (CLM) was reported from Mexico for
first time in September 1994. This insect spread rapidly over the main citrus-growing
areas and it became a serious threat to the citrus industry in Mexico. The options for
controlling this pest include chemical control and natural biological control. The ob
jective of this investigation is to identify the parasitoids associated with the CLM and
the variation in their populations in Persian lime, Citrus aurantifolia cv 'Tahiti', at
Cuitlahuac, Veracruz, Mexico. The species found are: Cirrospilus sp. n. 1, Cirruspilus
sp. n.2, Horismenus sp., Galeopsomyia sp. and Elasmus tischeriae. From November to
March of 1995-96, parasitism of the CLM was more than 70% and the most abundant
parasitic species were Galeopsomyia sp. and Cirrospilus sp. n. 1 and sp. n. 2.

Key Words: Phyllocnistis citrella, Citrus aurantifolia, parasitoids, citrus

RESUME

El minador de la hoja de los citricos Phyllocnistis citrella (MHC) se registry por pri
mera vez en Mexico en septiembre de 1994. El insecto se extendi6 rapidamente por las
principles areas citricolas y se ha convertido en una seria amenaza para la citricul
tura mexicana. Las tendencies para el control de la plaga senalan el uso del control
quimico y el control biol6gico natural. A este respect, el objetivo del present trabajo
es conocer los parasitoides asociados con el MHC y su fluctuaci6n poblacional en lim6n
Persa, Citrus aurantifolia cv. 'Tahiti', en Cuitlahuac, Veracruz. Las species encontra
das son: Cirrospilus sp. n. 1, Cirrospilus sp. n. 2, Horismenus sp., Galeopsomyia sp. y
Elasmus tischeriae. Durante los meses de noviembre a marzo de 1995-96 se observe


March, 1998

















Bautista Martinez et al.: Parasitism ofPhyllocnistis citrella 31

un parasitismo de MHC mayor del 70%, y las species mas abundantes fueron: Ga
leopsomyia sp. y Cirrospilus sp. n. 1 y sp. n.2.





The Citrus Leafminer (CLM) Phyllocnistis citrella Stainton (Lepidoptera:Gracilla
riidae) was found first in 1993 in Florida USA, (Heppner 1993) and in September 1994
in Tamaulipas and Veracruz, Mexico (Ruiz and Coronado 1994) from these points of
introduction, it spread rapidly through the main citrus-producing areas of Mexico. At
the present time it is difficult to locate an area free of this pest, which now threatens
citrus production in Mexico. In the southern part of Veracruz State, where Cuitlahuac
is located, the problem is especially serious because Persian lime, Citrus aurantifolia
(Christm.) Sweet cv 'Tahiti', is severely damaged by this insect. Other insect species
such as the mealybug Planococus citri and snow scale Unaspis citri also contribute to
the pest problems in the area.
The CLM has its origin in South Asia, where it was observed in Calcuta, India, for
the first time in 1865 (Sponagel and Diaz 1994). In this century the pest has spread
to many countries through shipments of plant materials and by migration. This insect
damages the young tender leaves of all species of the genus Citrus. In addition,
Clausen (1931) reported that the pest also damages Aeple marmelos, Murraga
koenigii and Jasminium sombae, and Quayle (1941) mentioned that CLM feeds on
species of Loranthus. CLM reduces possibly the photosynthetically active leaf area of
its host both by destroying mesophyll cells and by rolling the leaves during pupation.
The pest is most destructive in young plantations, where it may cause total defoliation
if it is not controlled. Furthermore, as Guerout (1994) pointed out, the mine built by
insect favors the development of citrus canker, Xanthomonas citri, and other fungus
pathogens such as Alternaria.
At present, CLM control practices consist of the application of chemical products
as well as natural biological control. Classical biological control is another option, us
ing the non-native parasitoid Ageniaspis citricola (Hymenoptera:Encyrtidae), which
has reduced significantly damage by the CLM in Australia (Knapp et al. 1995).
In Mexico, various species of native parasitoids, principally members of the family
Eulophidae, have been reported (Table 1). Most of these are ectoparasites and attack
not only lepidopteran leafminers, but also those belonging to other orders.
The main objective of this work is to identify the species of parasitoids associated
with the CLM at Cuitlahuac and to learn about their effectiveness in controlling the
pest at this location.


MATERIALS AND METHODS

Field work was conducted from August, 1995, to September, 1996, at Cuitlahuac,
Veracruz (Fig. 1). This area is located at 18'50' North latitude, 96'55' West longitude
and is 420 meters above sea level. Total precipitation in 1995 was 2, 200 mm, with a
temperature that varied from 12'C to 36'C. The rainy season is from June to Novem
ber (Fig. 2) (Bautista et al. 1996).
The collections were made mainly from Persian lime but some were made from
sweet orange (Citrus sinensis (L.) Osbeck) and tangerine (C. reticulata Blanco). Every
week 10 flushes less than eight centimeters long, in five different trees (50 flushes in
total) were examined to determine the level of infestation by CLM. Parasitism of the
CLM was detected by collecting a total of 1609 infested leaves located at or below the

















Florida Entomologist 81(1)


TABLE 1. PARASITOID SPECIES ASSOCIATED WITH THE CLM IN MEXICO (RUIZ & MA
TEOS 1996, MARTINEZ & RUIZ 1996, PERALES ET AL. 1996).


Taxon


Locality


Cirrospilus quadristriatus
Cirruspilus sp


Closterocerus sp




Horismenus sp


Pnigalio sp
Tetrastichus sp

Zagrammosoma sp


Tecoman, Colima.
Tecoman, Colima.
northern Veracruz
central Tamaulipas
Tecoman, Colima.
Tecoman, Colima.
northern Veracruz
central Tamaulipas
Tecoman, Colima.
northern Veracruz
central Tamaulipas
central Tamaulipas
Tecoman, Colima.
northern Veracruz
Tecoman, Colima.
central Tamaulipas


middle of flushes 20 cm length. These leaves were placed in paper bags and taken im
mediately to the laboratory where the relative humidity was between 65 to 75% and
the temperature varied between 18 and 25 C. The leaves were placed in Petri dishes,
three per dish, with their petioles wrapped in moist cotton, and observed daily until
emergence of the adult CLM or its parasitoids. It was necessary to control the humid





S.. ..., Cuitlahuac, Ver.


Fig. 1. Location of the area of study of the CLM.


March, 1998


















Bautista Martinez et al.: Parasitism ofPhyllocnistis citrella 33


I ..... .- ......-.....-...... -... -... ..........
Au asW OCT WOV MDEC Fr M UL APL MAX. AN As
norans

Fig. 2. Variation in temperature, precipitation and the number of citrus leafminers
between August, 1995, and July, 1996, at Cuitlahuac, Veracruz.


ity because dehydration of the leaves or contamination by saprophytic fungi due to ex
cess humidity can affect the emergence of the insects. Some of the wasps that emerged
were placed in 70% alcohol and others were dehydrated with a critical point drier and
pinned for identification. Another procedure that was used to collect parasitoids con
sisted of selecting infested leaves and enclosing them is small bags of organdy, with
out removing them from the tree. They were examined every day until emergence of
the adult insects. A total of 312 leaves from 39 flushes were treated this way
The parasitoids were identified using the keys of Schauff and LaSalle (1996). In
addition, the eulophids were sent to the Centro Nacional deReferencia de Control Bi
ol6gico in Tecoman, Colima, Mexico and to Dr. John LaSalle, at the International In
stitute of Entomology, in London, England, for confirmation. To confirm the
determinations of the elasmids, specimens were sent to Dr. Lonny D. Coote, at the
Royal Ontario Museum, in Canada.


RESULTS AND DISCUSSION

The highest population levels of the CLM were observed in September, October,
April and May while the lowest incidence occurred in the months of January and July
(Fig. 2). Incidence of the CLM was not closely related to the development of new
flushes. In January and July most of these flushes were free from the pest (Table 2).
In addition a high level of parasitism, above 70%, was observed from November to
March. In June and July a high percentage of parasitism was observed on the few leaf
miners collected (Fig. 2).
Five species of parasitoids in the superfamily Chalcidoidea (Table 3) were reared
from the 1609 infested leaves that were taken to the laboratory for this purpose. The
first four species belong to the family Eulophidae (Hymenoptera). Cirrospilus 1 and 2

















Florida Entomologist 81(1)


TABLE 2. VARIATION IN THE INCIDENCE OF THE CLM AND ITS PARASITOIDS AT CUIT
LAHUAC, VERACRUZ IN 1995-96.

CLM larvae CLM larvae
Leaves and/or pupae and/or pupae Percent
Month examined found parasitized parasitized

Aug. 225 207 68 32.8
Sep. 291 301 148 49.1
Oct. 229 158 92 58.2
Nov. 191 148 107 72.2
Dec. 95 18 15 83.3
Jan. 63 7 6 85.7
Feb. 94 11 9 81.8
Mar. 111 31 22 70.9
Apr. 201 104 71 68.2
May. 109 62 29 46.7
Jun. 67 12 9 75
Jul. 45 4 4 100


and Galeopsomyia sp yet have not been described. The neotropical genus Horismenus
is very difficult taxonomically, so it is not possible to be sure if the species collected is
undescribed or not (LaSalle 1997, personal communication). Elasmus tischeriae is in
the family Elasmidae, species of which generally attack species in the orders Diptera
and Coleoptera.
In the months of August and September the parasitoids population on the CLM
were reduced considerably, possibly because they were attacking other species of leaf
miners.


Cirrospilus

LaSalle (1996) reported fifteen species of Cirrospilus associated with the CLM, in
cluding the undescribed species collected in this study. The same author states that


TABLE 3. PARASITOIDS OF THE CLM AND THEIR RELATIVE IMPORTANCE AT CUIT
LAHUAC, VERACRUZ.

Percent
Species parasitized Biological phase attacked'

Cirrospilus sp 1 22.6 Larvae III (2) and prepupae(7)
Cirrospilus sp 2 25.1 Larvae 111(2), prepupae(1) and pupae(9)
Horismenus sp 19.3 Prepupae(1) and pupae(13)
Galeopsomyia sp 27.6 Larvae II(1), III(1), prepupae(4) and pupae(7)
Elasmus tischeriae 5.4 Larvae 11(2), III(1) and pupae(2)

0 number of individuals observed.


March, 1998

















Bautista Martinez et al.: Parasitism ofPhyllocnistis citrella 35

this is a cosmopolitan and polyphagous genus although it prefers to parasitize insects
in the family Gracillaridae. Sometimes the members of Cirrospilus act as hyperpara
sitoids (LaSalle 1996), even though this the species collected at Cuitlahuac, Veracruz
were not observed doing this. The two Cirrospilus species found at Cuitlahuac are ec
toparasitic, the pupae remaining in the mines of the host.

Galeopsomyia

The collection at Cuitlahuac is the first record of the genus for Mexico (Bautista et
al. 1996). This species, which is being described by LaSalle, is ectoparasitic on the
CLM in the larval phases II and III and prepupae. In one case it was observed as a fac
ultative solitary hyperparasitoid. The highest incidence of this species was observed
in October and November. According to LaSalle (1994), the species of this genus gen
erally attack Cecidomyiidae (Diptera) and Cynipidae (Hymenoptera).

Horismenus

This ectoparasitoid of the CLM, can be confused with Galeopsomyia. LaSalle
(1996) reported two species of Horismenus associated with the CLM which have not
yet been described. It is very common to find species of this genus acting as hyperpar
asitoids (Coffelt and Sehultz 1993).

Elasmus

Of the five species of parasitoids associated with the CLM, E. tischeriae Howard
was the least abundant at Cuitlahuac; only about 5% of the parasitoid individuals
were of this species. LaSalle (1994) reports three species attacking the CLM, E. tis
cheriae, E. zenhtneri and an undescribed species. To date, E. tischeriae is the only one
that has been found in Mexico. Some authors place this species in the family Eu
lophidae instead of the monotypic Elasmidae. It is the capable of parasitizing lepi
dopteran borers, but it also has been frequently found parasitizing species of Polistes
(Hymenoptera: Vespidae) (Borror et al. 1989). In the study area this species was ob
served in the months of August and September.


Other predators

Several other predatory arthropods associated with the CLM were observed at
Cuitlahuac. These include syrphid flies, common lacewings, spiders (Table 4) and the
ant species, Crematogaster aff-brevispinosa and Conomyrma bicolor (Hy-
menoptera:Formicidae).


TABLE 4. SPIDER SPECIES ASSOCIATED WITH CLM, AT CUITLAHUAC, VERACRUZ.

Family Species

Araneidae Araneus sp
Leucauge argyra Walckanaer
Argiope argentata Fabricius
Salticidae Habronatus sp
Theridiidae Thymoites unimaculatum

















Florida Entomologist 81(1)


CONCLUSIONS

The highest population levels of the citrus leafminer occurred in September and
October, then in April and at the beginning of May. The lowest incidence of the pest
was observed in January and July. The parasitoid species with the highest percent
age; of parasitism were Cirrospilus and the Galeopsomyia. In the period from Novem
ber to March, the level of parasitism was very high, about 70%.


ACKNOWLEDGMENTS

This study was supported by Consejo Nacional de Ciencia y Tecnologia (CONA
CYT), through Project 0503 PB "Bioecologia del minador de la hoja de los citricos
Phyllocnistis citrella Stainton (Lepidoptera: Gracillariidae). Una nueva plaga para la
citricultura mexicana". The authors thank Dr. J. LaSalle and Dr. D. Lonny Coote, of
the International Institute of Entomology, London, England, and Department of En
tomology, Royal Ontario Museum, Toronto, Canada, respectively, for their assistance
in the identification of the parasitoids. Identification of the ants was made by M. C.
Luis Quiroz Robledo, Institute de Ecologia, A. C., Jalapa, Veracruz, Mexico. Identifi
cation of the spiders was made by Dr. Carlos Solis Rojas, Universidad Autonoma de
Nuevo Leon, Linares, Mexico.


REFERENCES CITED

BAUTISTA, M., N., H. BRAVO M., AND J. L. CARRILLO S. 1996. Estado actual y perspec
tivas para el manejo del minador de la hoja de los citricos Phyllocnistis citrella
en Mexico. VI Congreso Nacional de Manejo Integrado de Plagas. Acapulco,
Guerrero, Mexico. Memorias: p. 81.
BORROR, D. J., D. M. DELONG, AND C. A. TRIPLEHORN. 1989. An Introduction to the
Study Insects. Ed.6. Holt. Reinhart and Winston, New York. 712-713 pp.
CLAUSEN, C. P 1931. Two citrus leafminers of the far East. U.S. Dept. Agric. Tecn.
Bull. 252. 13 pp.
COFFELT, M. A., AND P. B. SCHULTZ. 1993. Larval parasitism of orangestriped oak
worm (Lepidoptera:Saturniidae) in the urban shade tree environment. Dept.
Entomology. University of Virginia. Abs. Biological Control 3(2): 127-134.
GUEROUT, R. 1994. Apparition du Phyllocnistis citrella en Afrique de 1' Ouest. Fruits
29:519-523.
HEPPNER, J. B. 1993. Citrus leafminer Phyllocnistis citrella Stainton (Lepi
doptera:Phyllocnistinae). Florida Dept. Agric. Consumer Services, Divis. Plant
Indust., Ent. Circular 359.2 pp.
KNAPP, J. L., L. G. ALBRIGO., H. W. BROWNING, R. C. BULLOCK, J. B. HEPPNER, D. G.
HALL, M. A. HOY, R. NGUYEN, J. E. PENA, AND P. A. STANSLY. 1995. Citrus leaf
miner Phyllocnistis citrella Stainton. Current status in Florida 1995. Coop.
Ext. Serv, IFAS, Univ. Florida, Gainesville. 26 pp.
LASALLE, J. 1994. North American genera of the Tetrastichinae (Hymenoptera:Eu
lophidae). J. Natural History 28: 109-236.
LASALLE, J. 1996. The genera of chalcid parasitoids (Hymenoptera: Chalcidoidea) of
the citrus leafminer (Lepidoptera:Gracillariidae). P 60 in M. A. Hoy (ed.), Man
aging the citrus leafminer, Proc. Intern. Conf, Orlando, Florida, University of
Florida, Gainesville. 119 pp.
MARTINEZ, B., AND E. RUIZ C. 1996. Citrus leafminer native parasitoids in midland
Tamaulipas, Mexico. P. 89 in M. A. Hoy (ed.), Managing the citrus leafminer,
Proc. Intern. Conf, Orlando, Florida, University of Florida, Gainesville. 119 pp.
PERALES, G. A., H. C. ARREDONDO B., AND E. GARZA G. 1996. Native parasitoids of cit
rus leafminer Phyllocnistis citrella in Colima, Mexico. Southwestern Entomol
ogist 21:349-350.


March, 1998

















Bautista Martinez et al.: Parasitism ofPhyllocnistis citrella 37

QUAYLE, H. J. 1941. Insects of Citrus and Other Subtropical Fruits. Comstock Pub
lishing Company Inc. Ithaca, New York. 582 pp.
RUIz, C. E., AND J. M. CORONADO B. 1994. El minador de la hoja de los citricos Phy
l]ocnistis citrella Stainton (Lepidoptera:Gracillariidae:Phyllocnistinae). Cent.
Investig., Fac. Agron. Univ. Auton. Tamaulipas. Folleto Entomol. 1. 2 pp.
RUIz, C. E., AND R. MATEOS C. 1996. Phyllocnistis citrella Stainton parasites in north
ern Veracruz, Mexico. in M. A. Hoy (ed.), Managing the citrus leafminer, Proc.
Intern. Conf., Orlando, Florida, University of Florida, Gainesville. 119 pp.
SCHAUFF, M. E., AND J. LASALLE. 1996. Identification Manual. Citrus Leafminer Par
asitoid Identification Workshop. Orlando Florida. 41 pp.
SPONAGEL, K. W., AND F. J. DIAZ. 1994. El Minador de la Hoja de los Citricos Phylloc
nistis citrella: Un Insecto-plaga de Importancia Econ6mica en la Citricultura
de Honduras. Fundaci6n Hondurena de Investigaci6n Agricola. La Lima Cor
tes. 25 p.


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Michaud: Review of Literature on Toxoptera citricida 37





















A REVIEW OF THE LITERATURE ON TOXOPTERA CITRICIDA
(KIRKALDY) (HOMOPTERA: APHIDIDAE)

J. P. MICHAUD
Citrus Research and Education Center, 700 Exp. St. Rd., Lake Alfred, FL 33850

ABSTRACT

Literature is reviewed on the brown citrus aphid (BCA), Toxoptera citricida
Kirkaldy, a serious pest of citrus recently introduced to Florida. Information is sum
marized on the aphid's distribution, host range, biology, population ecology, natural
enemies, entomopathogens, transmission of plant viruses, and management.

Key Words: citrus tristeza virus, coccinellidae, control, parasitoids, predators, syr
phidae

RESUME

Es revisada la literature sobre el pulg6n pardo de los citricos, Toxoptera citricida
Kirkaldy, una plaga de citricos reci6n introducida en la Florida. La informacidn esta
resumida en cuanto a la distribucidn del afido, sus plants hospederas, biologia, eco
logia, enemigos naturales, entomopatologia, transmisi6n de virus, y control.





The brown citrus aphid, Toxoptera citricida, (BCA) was first discovered in Florida
in November, 1995 in Broward and Dade Counties. BCA is a major concern to citrus
growers throughout the state because of its high efficiency in transmitting citrus
tristeza virus (CTV). In view of the current interest in this insect, the purpose of this
manuscript is to summarize information available on its biology, ecology, and manage
ment, and its role as a vector of CTV. The volume of literature on CTV warrants a sep
arate review and I have therefore referenced only review articles and those
specifically concerned with CTV transmission by the BCA.

















Florida Entomologist 81(1)


The BCA, a.k.a. the oriental citrus aphid, was formerly called "Aphis citricidus"
(1935-1960) and then Toxoptera citricidus before the species name was changed to its
present form to agree in gender with the genus name (Stoetzel 1994a). In earlier lit
erature (prior to 1940) it was commonly referred to as "Aphis tavaresf'. Other syn
onyms include "Myzus citricidus" and "Paratoxoptera argentiniensis", but usage of
these names is rare. Essig (1949) lists "Aphis citricola" Van der Goot as synonymous
with T citricida, but Hille Ris Lambers (1975), upon re-examination of the original
material collected by Van der Goot in Chile (Van der Goot 1912), concluded that A. cit
ricola is synonymous with Aphis spiraecola Patch, the green citrus aphid, and this
was later confirmed by Eastop and Blackman (1988). A. citricola has been used as a
synonym for A. spiraecola in some literature (e.g. Komazaki 1982, 1988), although in
pre-1950 publications it often appears as a synonym for BCA. Further confusion
arises in studies where the BCA has been mistaken for its close relative T aurantii
Kirkaldy, and such cases are difficult to identify.
Many of the large number of publications which refer to BCA make only passing
reference to it, or report it as one of many species collected in a general survey of cit
rus insects. I have therefore reviewed in detail only those articles which I felt provided
original data, useful observations, or novel insights. The information has been orga
nized under subject headings to provide readers with quick access to particular areas
of interest.


DESCRIPTION & DISTRIBUTION

Toxoptera citricida was first described by Kirkaldy (1907) who placed it in the ge
nus Myzus. Good descriptions can also be found in Essig (1949), Stroyan (1961), Ban
ziger (1977), Denmark (1978), Stoetzel (1994b), and Halbert and Brown (1996). The
latter provides a detailed description complete with drawings and a key for distin
guishing other aphids common in Florida citrus. The cytotaxonomy of the Genus Tox
optera, including BCA, has been described by Kurl (1980).
The BCA is thought to have originated in Southeast Asia (Kirkaldy 1907; Rocha
Pena et al. 1995) and is common throughout Asia, including China, Cyprus, India, Ja
pan, Laos, Taiwan, Viet Nam (Essig 1949), Sumatra (Takahashi 1926; Mason 1927),
Nepal (Knorr & Moin Shah 1971), Sri Lanka (Van Der Goot 1918; Peiris & Bertus
1958), Malaysia (Ting 1963; Ting & Arasu 1970), the Philippines (Gavarra & Eastop
1976) and Thailand (Banziger 1977). Pacific islands with records include Hawaii
(Kirkaldy 1907), Fiji (Lever 1940), Mauritius (D'Emmerez De Charmoy 1918; Mamet
1939), Reunion (Moreira 1967), Samoa (Laing 1927), and Tonga (Carver et al. 1994).
BCA has been present in Australia for many years, possibly since the last century
(Hely 1968) and can also be found in New Zealand (Cottier 1935).
Specimens of BCA collected by J. S. Tavares in Zambezi were described by Del
Guercio in 1908 who named it "Aphis tavaresi' (Del Guercio 1917). Anderson (1914)
and Theobald (1915) both reported collections of BCA from British East Africa. Other
african countries with records include Cameroon, Congo, Ghana, Kenya, Morocco,
South Africa, Tanzania, Uganda, Zaire, Zimbabwe (Essig 1949), Ethiopia (Del Guercio
1917; Abate 1988; Godfrey-Sam-Aggrey & Balcha 1988), Mozambique, (Saraiva 1929;
Annecke 1963) Somalia (Theobald 1928; Chiaromonte 1933), and Tunisia (Halima et
al. 1994). It is still absent from Israel (Bar-Joseph & Loebenstein 1973; Raccah &
Singer 1987). Essig (1949) reported BCA as present in Italy, Malta and Spain, but
these reports are questionable and remain unconfirmed. Although apparently present
in Turkey (Yumruktepe & Uygun 1994) the BCA is still absent from much of mediter
ranean Europe (Mendel 1956; Jamoussi 1967).


March, 1998

















Michaud: Review of Literature on Toxoptera citricida


Accidental introductions of BCA (and CTV) to South America are thought to have
been made in either Brazil or Argentina during the 1920's when these regions were
expanding their citrus production and importing material from Australia and South
Africa (Rocha-Pena et al. 1995). Since that time it has spread to Bolivia (Squire 1972;
Timmer et al. 1981), Peru (Roistacher 1988), Uruguay, Chile, and Colombia, (Rocha
Pena et al. (1995). It has even been found in jungle regions of the Peruvian Amazon
(Ortiz 1981). BCA was first reported in Venezuela in 1976 (Geraud 1976), although it
had been present in neighboring Guyana since at least 1968 (Bisessar 1968) and in
Surinam since 1961 (van Hoof 1961). BCA first appeared in the Caribbean islands in
Trinidad in 1985 (Yokomi et al. 1994). In 1991 it was found in Guadeloupe, Martin
ique and St. Lucia (Aubert et al. 1992) and in 1992, in Puerto Rico and the Dominican
Republic (Lastra et al. 1992). It is now also present in Jamaica and Cuba (Yokomi et
al. 1994). The BCA had spread into Central America as far north as Costa Rica by
1989 (Lastra et al. 1991,Voegtlin and Villalobos 1992), to Nicaragua and El Salvador
in 1991 (Lastra et al. 1992, Lee et al. 1992), and to Belize in the fall of 1996 (Halbert
1996). In the fall of 1995, the BCA arrived in Florida in the Ft. Lauderdale area and,
within one year, spread as far north as Melbourne on the east coast and Ft. Meyers on
the west (Halbert 1997). By the summer of 1997, BCA was widely distributed
throughout southern central and coastal regions of Florida, although it remained ab
sent from much of the ridge citrus north of Highlands county


HOST RANGE

The host range of the BCA is largely restricted to the Genus Citrus, although there
are many reports of it colonizing other rutaceous plants. A list of the host plants from
which BCA has been reported is provided in Table 1. The majority are woody shrubs,
although some are perennial vines and annual herbs. Symes' (1924) report of a single
infestation on cotton was from Rhodesia. Tao & Tan (1961) collected their specimens
in Taiwan. Collections by Mondal et al. (1976) are from India and those of Carver
(1978) are all from Australia. Van Harten & Ilharco (1975) and Remaudiere et al.
(1985) reported collections from Africa. Ghosh & Raychaudhuri (1981) reported find
ing the BCA feeding on rosaceous fruit trees in India (apple, cherry, peach etc.spe
cies names not provided), although I suspect this to be a possible mis-identification of
T aurantii. The record from white yam, Dioscorea rotundata, (Reckhaus 1979) is from
Togo and that for Passiflora sp. (Bakker 1974), from Kenya. All collections reported by
inspectors of the Florida Department of Agriculture and Consumer Services, Division
of Plant Industry, are from Florida.
Most non-rutaceous plants are not normally suitable hosts for the BCA and it
should be noted that collections from these plants do not imply they are suitable for
development and reproduction of the aphid. These may be colonized occasionally by
variant individuals when suitable citrus foliage is unavailable, or alates may be col
elected that are resting rather than feeding. Several generations of BCA were reared
successfully in the laboratory on seedlings of West Indian cherry (a.k.a. acerola), Mal-
pighia punicifolia, in Puerto Rico, although natural colonization of this plant could
not be elicited by placing flushed seedlings adjacent to infested citrus (Michaud 1996).
Halbert et al. 1986 has been erroneously cited as a host record for BCA on soybean,
Glycine max, (Stibick 1993) but this work examined only transmission of soybean mo
saic virus by BCA. Many of the anomalous occurrences (e.g. cotton) probably repre
sent isolated events or colonizations by variant populations that are atypical of the
species' normal host range, although others probably represent mis-identifications
(Stoetzel 1994b).

















Florida Entomologist 81(1)


TABLE 1. HOST RECORDS FOR THE BROWN CITRUS APHID. NOTE: ALL PLANTS IN THE GE
NUS CITRUS ARE HOSTS AND ARE NOT LISTED BY SPECIES.

Anacardiaceae
Mangifera sp. (Carver 1978)
Mangifera indica (Stibick 1993)
Rhus sp. (Mondal et al. 1976)

Bombaceae
Bombax ceiba (Tao & Tan 1961)

Burseraceae
Commiphora mollis (Remaudiere et al. 1985)

Camelliaceae
Camelliajaponica (Tao & Tan 1961)

Caryophyllaceae
Dianthussp. (Mondal et al. 1976)

Dioscuraceae
Dioscorea rotundata (Reckhaus 1979)

Ebenaceae
Diospyros kaki (Essig 1949)
Diospyros sp. (Carver 1978)

Ericaceae
Azalea sp. (Essig 1949)
Rhododendron sp. (Stibick 1993)

Euphorbiaceae
Bridelia monoica (Tao & Tan 1961)
Bridelia ovata (Tao & Tan 1961)
Clutia abyssinicam (Remaudiere et al. 1985)

Fagaceae
Quercus sp. (Mondal et al. 1976)

Flacouatiaceae
Xylosna congestum (Tao & Tan 1961)

Juglandaceae
Engelhardtia spicata (Mondal et al. 1976)

Leguminoceae
Cassia absus (Mondal et al. 1976)
Cassia sp. (Mondal et al. 1976)

Lauraceae
Cinnamomum camphora (Tao & Tan 1961)
Litsia polyantha (Mondal et al. 1976)


March, 1998

















Michaud: Review of Literature on Toxoptera citricida


TABLE 1. (CONTINUED) HOST RECORDS FOR THE BROWN CITRUS APHID. NOTE: ALL
PLANTS IN THE GENUS CITRUS ARE HOSTS AND ARE NOT LISTED BY SPECIES.

Malpighiaceae
Malpighia punicifolia (J. P Michaud unpublished)

Malvaceae
Gossypium hirsutum (Symes 1924; Carver 1978)

Moraceae
Cudrania triscuspidata (Essig 1949)
Ficus carica (Essig 1949)
Ficus ingens (Remaudi6re et al. 1985)
Ficus retusa (Tao & Tan 1961)
Malclura cochinchinensis (Carver 1978)

Mysinaceae
Maesa chisea (Mondal et al. 1976)
Maesa sp. (Mondal et al. 1976)

Nyctaginaceae
Bougainvillea spectabilis (Remaudiere et al. 1985)

Oxalidaceae
Oxalis pes-caprae Carver (1978)

Passifloraceae
Passiflora foetida (Mondal et al. 1976)
Passiflora sp. (Bakker 1974)

Rosaceae
Cottoneastersp. (Carver 1978)
Crataegus sp. (van Harten & Ilharco 1975)
Eriobotrya sp. (Tao & Tan 1961)
Malus domestic (van Harten & Ilharco 1975)
Malus sylvestris (Mondal et al. 1976)
Pyrus communis (Essig 1949; van Harten & Ilharco 1975; Mondal et al. 1976)
Pyrus sp. Carver (1978)

Rubiaceae
Lasianthus chinensis (Tao & Tan 1961)

Rutaceae
Calodendrum capense (Carver 1978)
Choisya ternata (Carver 1978)
Citrifortunella floridana (Fla. Dept. Agr. & Cons. Serv, D.P.I., Gainesville, FL.)
Citrifortunella microcarpa (Fla. Dept. Agr. & Cons. Serv, D.P.I., Gainesville, FL.)
Citrus spp.
Clausena lanisum (Fla. Dept. Agr. & Cons. Serv, D.P.I., Gainesville, FL.)

















Florida Entomologist 81(1)


TABLE 1. (CONTINUED) HOST RECORDS FOR THE BROWN CITRUS APHID. NOTE: ALL
PLANTS IN THE GENUS CITRUS ARE HOSTS AND ARE NOT LISTED BY SPECIES.

Eremocitrus glauca (Carver 1978)
Evodia hupehensis (Meneghini 1948)
Geijera parviflora (Carver 1978)
Flindersia xanthoxyla (Carver 1978)
Fortunella sp. (Stibick 1993)
Fortunella margarita (Carver 1978)
Murraya exotica (Stibick 1993)
Murraya paniculata (Tao & Tan 1961; Carver 1978)
Poncirus trifoliata (Essig 1949; Tao & Tan 1961; Carver 1978)
Severinia buxifolia (Carver 1978)
Toddalia asiatica (Essig 1949)
Triphasia trifolia (Fla. Dept. Agr. & Cons. Serv, D.P.I., Gainesville, FL.)
Vepris undulata (Carver 1978)
Zanthoxylum fagara (Fla. Dept. Agr. & Cons. Serv, D.P.I., Gainesville, FL.)
Zanthoxylum ornatum (Mondal et al. 1976)
Zanthoxylum sp. (Mondal et al. 1976)

Ternstroemiaceae
Schima wallichii (Mondal et al. 1976)

Ulmaceae
Ulmus procera (Carver 1978)
Trema orientalis (Essig 1949)

Urticaceae
Boehmeria sp. (Mondal et al. 1976)


BASIC BIOLOGY

The BCA feeds only on newly expanded shoots, leaves and flower buds of its host
plants. Newly expanding terminals are suitable for BCA growth and reproduction for
usually a period of only 3-4 weeks, depending on environmental conditions. Therefore,
a BCA colony has a relatively narrow time window within which to mature and pro
duce alates prior to the demise of its food resource. This is an important consideration
in the development of management strategies since only those colonies exporting
alates are of importance in terms of the secondary transmission of CTV. In this con
text it is unfortunate that no laboratory studies have yet examined the environmental
conditions that induce the production of alate morphs in BCA. Crowding of nymphs
seems to induce alate formation (J. P. Michaud unpublished), but declining food qual
ity and temperature may also play a role. However, once shoot hardening progresses
beyond some threshold point, BCA nymphs either fail to mature or leave the terminal
in search of new flush on other branches.
Despite the fact that the BCA can apparently move long distances in a short pe
riod, it is not clear to what extent this results from natural dispersal as opposed to ac
cidental movement by man. My own observations indicate that the majority of alates


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Michaud: Review of Literature on Toxoptera citricida


probably do not fly far from their nascent colony. This is borne out by the fact that foci
of BCA infestations are often localized in citrus groves and can be observed to expand
more slowly than those of Aphis,_. ., - (Gottwald et al. 1995). Furthermore, suction
and yellow-trap catches often underestimate the number of active BCA colonies in a
particular vicinity (e.g. Yokomi et al. 1997). Consequently, BCA infestations tend to be
endemic in citrus groves, surviving at low density on bits of asynchronous flush and
root sprouts until a new flush cycle provides sufficient food for a population outbreak.
Weather conditions such as thermal updrafts or tropical storms may play some role in
dispersal. For example, the discovery of BCA in Jamaica in 1993 was preceded by the
passage of a strong tropical depression (Lee et al. 1995, p. 209). However, long-range
dispersal by alates is probably rare and movement of infested plant material by hu
mans may be a more important mechanism. Gottwald et al. (1993) estimated very low
probabilities for colonization of Florida citrus by BCA through arial dispersal from the
Carribean, specifically Cuba, but the true mechanism by which it ultimately arrived
in Florida was never established.
The earliest detailed study of the biology and life history of the BCA is by Symes
(1924) in Southern Rhodesia. The author reported as many as 30 generations per
year, depending on availability of citrus flush. The time for development to adult was
estimated to range from 8 to 21 d. The BCA is anholocyclic (without sexual genera
tions) throughout most of its range in tropical and subtropical regions. In New
Zealand, Cottier (1935) observed the anholocyclic apterae to overwinter, although
their development was greatly retarded. Komazaki et al. (1979) observed a holocyclic
generation of BCA under temperate conditions in Japan. However, the authors found
very few overwintering eggs of BCA on trees compared to the numbers of A. ,
and A. spiraecola eggs. Furthermore, although hatching rates were similar across spe
cies, the survival rate of hatched BCA nymphs was very low and surviving adult fun
drices produced no second generation. In the laboratory, Komazaki (1990) compared
the development and reproduction of BCA fundrices hatched from eggs with that of
subsequent viviparous generations and found that the former took longer to mature
at all temperatures tested, and had a lower reproductive rate. Because of low over
wintering populations, the BCA is the last of the citrus aphids to appear on spring
flush in Japan (Komazaki 1988).
Takanashi (1989) compared the reproductive rates of alate and apterous morphs
of the BCA feeding on Citrus natsudaidai in the laboratory. The pre-reproductive pe
riod was longer for alatae than for apterae at both 20 and 25'C, and estimates of both
age-specific fecundity and net reproductive rate were higher for apterae at both tem
peratures. Komazaki (1982) determined that the maximum intrinsic rate of increase
for the BCA occurred at a constant temperature of 27'C, even though the fecundity
and net reproductive rate of individual apterous females was maximal at 21.5'C. In
general, the pre-reproductive period, post-reproductive survival, and longevity were
all shortened as temperature increased.
Galatoire (1983) calculated life table statistics for 3 cohorts of BCA grown in out
door enclosures in Argentina. She reported mean life expectancies for apterous fe
males ranging from 28 to 48 d; the shorter life expectancies correlated with higher
mean daily temperatures and reduced duration of the third and fourth nymphal in
stars. Age-specific mortality rates varied among cohorts, presumably in response to
the different ambient conditions they experienced, although >80% of individuals sur
vived to become adults in all 3 cohorts. Daily fecundity of adult apterae averaged be
tween 5 and 6 nymphs per female per day, and total fecundities ranged between 73
and 81 nymphs. The highest mean replacement rate (59 females/female) was observed
in a cohort which experienced a moderate regime of daily temperatures, but the high
est instantaneous rate of increase was observed in the cohort experiencing the highest

















Florida Entomologist 81(1)


mean daily temperatures. This result was attributed to reduced generation time un
der the warmer conditions.
There is also evidence that the performance of BCA varies on different species of
citrus. Komazaki (1982) observed differences between BCA reared on Citrus unshui
and those reared on C. aurantium. He also discovered a temperature-host plant inter
action effect on development. C. unshui yielded aphids with shorter pre-reproductive
periods and greater longevities and fecundities than did C. aurantium. The threshold
temperature for BCA development was also lower on C. unshui (8.0 C) than on C. au
rantium (8.4 C). However, the survival rate on C. unshui was 0% at 29.7 C, but 60%
on C. aurantium at 29.9 C.
Komazaki (1984) succeeded in rearing 4 generations of BCA on an artificial diet of
20% sucrose at pH7, but the growth rate, fecundity, and longevity of these aphids were
reduced relative to those fed on citrus.


POPULATION DYNAMICS

Given that the BCA feeds only on tender new citrus terminals, many authors have
observed population outbreaks to occur about 2 wk following heavy rainfall that in
duces citrus flush (Schwarz 1965a; Klas 1979). Typically, there are two BCA popular
tion peaks per year in subtropical regions, one in the spring and another in the fall.
This has been observed in Argentina (Nickel & Klingauf 1985), Australia (Khan 1976;
Carver 1978), Brazil (Chagas et al. 1982), Kenya (Seif & Islam 1988), Puerto Rico (J.
P. Michaud unpublished), Taiwan (Tao & Tan 1961), and Japan (Nakao 1968; Shindo
1972). Komazaki (1981) reported three annual population peaks in Japan during one
year's observations.
Geraud (1979) studied the life cycle and population dynamics of BCA in Venezuela,
but I was unable to obtain a copy of this thesis. Nickel & Klingauf (1985) studied BCA
population dynamics for a 2-yr period in Misiones, Argentina. They compared the lon
gevity of exposed colonies with those in exclusion cages and others growing under cli
mate-controlled conditions indoors. The maximum longevity of exposed outdoor
colonies was only 12 d (mean= 7.5) compared with a range of 16-26 d in the exclusion
cages and 19-33 d under temperature-controlled conditions. The improved survival of
colonies in the exclusion cages was attributed, in part, to their protection from natural
enemies, primarily Cycloneda sanguinea (Coleoptera: Coccinellidae) and, in part, to
physical protection afforded by the enclosures. Periods of heavy rain and hot dry
weather were both correlated low BCA population densities. Heavy rainfall appeared
to impede flight activity as measured by catches in yellow bowl traps. Anderson (1914)
also noted a popular belief that BCA populations are checked by heavy showers. How
ever, Nickel & Klingauf (1985) concluded that temperature is an important determi
nant of BCA population trends and that temperature extremes in winter and summer
had a negative impact on development and flight activity. A negative effect of high
temperatures on BCA populations was also inferred by Hall (1930).


NATURAL ENEMIES

The BCA is unusual as an aphid species with few effective parasitoids throughout
its range (Stary 1970). One exception may be Japan where Lysiphlebiajaponica Ash
mead (Hymenoptera: Aphidiidae) reportedly exerts some level of control (Kato 1969,
1970; Takanashi 1990, 1991). This species was imported to Florida in 1996 and re
leased at 29 sites throughout the state, and to Puerto Rico where it was released at 2
sites. To date (Aug, '97) there no have been no recoveries of this insect from Puerto


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Michaud: Review of Literature on Toxoptera citricida


Rico. In April 1997, a few weeks after releases were made, a number of specimens of
L.japonica were recovered at several sites in St. Lucie County, Florida. This would in
dicate at least one generation of L.japonica was successful under field conditions in
Florida. However, it is still uncertain whether permanent establishment of this spe
cies will occur and, if so, whether any significant control of BCA will result.
Symes (1924) reports collecting a single unidentified Braconid (probably an Aphi
diid) parasitoid from BCA in South Africa, although Abate (1988) found no parasitoids
of BCA in his survey of citrus disease vectors in Ethiopia. Lysiphlebus testaceipes
Cresson attacks BCA in Venezuela (Stary & Cermeli 1989) and in Brazil (Gallo et al.
1978), although Murakami et al. (1984) did not recover this or any other species of
parasitoid from BCA during their survey in the Cerrados region. L. testaceipes is fre
quently observed parasitizing the BCA in Puerto Rico, but fewer than 5% of mummies
yield viable adults (Yokomi & Tang 1996). In Cuba, L. testaceipes frequently parasit
izes T aurantii but is only rarely found on BCA (Batista et al. 1995). Carver (1984)
found that L. testaceipes (imported to Australia) readily oviposited in BCA but rarely
completed development. Similarly, Carver & Woolcock (1985) reported incomplete
parasitism of BCA by Aphelinus asychis Walker in Australia. L. testaceipes is fre
quently found parasitizing BCA in most citrus-growing regions of Florida, although
very few mummies can be found with emergence holes (J. P. Michaud unpublished).
Nickel & Klingauf (1985) reported that, in Argentina, Aphidius colemaniViereck
parasitized up to 50% of BCA in some colonies in the fall, although no information is
presented on the survival of the parasitoid in this host. Stary & Cermeli (1989) made
collections of A. colemani from 10 spp. of aphids in Venezuela, but did not find it at
tacking BCA. Valencia & Narciso Cardenas (1973) reported collection of Aphidius ma
tricariae Haliday from BCA in Peru. De Huiza & Ortiz (1981) collected 4 spp. of
aphidiid wasps from aphids in Peru, including A. colemani and A. matricariae, but
only L. testaceipes emerged from BCA. Carver (1978) noted parasitism of BCA by A.
colemani in Australia, although she noted that such mummies were rare in the field.
Messing & Rabasse (1995) observed that A. colemani from Reunion Island oviposited
in various aphid species in which the wasp did not complete development. Newman
(1924) reports Aphelinus mali (Aphelinidae) emerging from BCA in Western Austra
lia. Flanders & Fisher (1959) reported collections of Lipolexis sp., Trioxys sp., and two
Aphelinus spp. from BCA in Kwantung Province, China. Yokomi et al. (1993) reported
a collection of Lipolexis scutellaris and L. gracilus from BCA in Malaysia and Tang et
al. (1996) report Aphelinus spiraecolae Evans and Shauff attacking BCA in China.
In most studies of the natural enemies of BCA, emphasis has been placed on pred
atory insects, primarily ladybeetles (Coleoptera: Coccinellidae), and hoverflies
(Diptera: Syrphidae) as species causing the greatest mortality to BCA populations.
Kato (1968) reported Eristrophe balteatus de Geer, Paragus quadrifasciatus Meigen,
Sphaerophoria cylindrica Say, and Syrphus serarius Wiedemann as hoverfly species
feeding on BCA in Japan. Symes (1924) reported Xanthogramma aegyptium Wied
mann as the most common syrphid preying on BCA in Rhodesia. Catling (1970) re
ported Allograpta pfeiferi Bigot and Baccha sp. as syrphid predators of BCA in South
Africa. Abate (1988) found Sphaerophoria rueppellii Wiedmann attacking BCA in
Ethiopia, as well as Leucopis spp. (Diptera: Chamaemyiidae). Lever (1946) lists Xan
thogramma (Ischiodon) scutellare F and Syrphus corollae var. vitiensis Bez. as the im
portant syrphids attacking aphids, including BCA, in Fiji. Goncalves & Goncalves
(1976) collected 10 species of syrphids from aphids in Sao Paulo and Rio de Janeiro
states in Brazil. Those attacking BCA included Allograpta exotica (Wiedmann.),
Ocyptamus gastrostactus (Wiedmann) (= Baccha gastroctacta) and Pseudodorus clav
atus (F) (= Baccha clavata). Bartoszeck (1980) also reported the latter two spp. as
predators of BCA in the state of Maranhao, Brazil. Leal et al. (1976) reported O. gas

















Florida Entomologist 81(1)


troctactus to be the most abundant syrphid on BCA in Pernambuco, Brazil and con
cluded it was the only predator affording any control. P clavatus and Ocyptamus
fuscipennis Say are the most abundant syrphids attacking BCA in Puerto Rico, al
though Allograpta exotica, A. radiata, and Ocyptamus cubanus have also been col
elected (J. P. Michaud unpublished). Valencia and Narciso Cardenas (1973) collected P
clavatus and Allograpta spp. in their survey of aphid natural enemies in Peru, but did
not find them feeding on BCA. P clavatus is also abundant on BCA in Cuba (Batista
et al. 1995) and in Trinidad where O. gastroctactus is also important (White 1995).
Collections from Florida suggest that P clavatus is by far the most abundant and
ubiquitous syrphid on BCA, but Toxomerus geminatus (Say) and Leucopis sp.
(Diptera: Chamaemyiidae) have also been recorded (J. P. Michaud unpublished).
Michaud (1996) observed relatively good biological control of BCA in Puerto Rico
throughout the summer months of 1996. Fewer than 5% of suitable citrus terminals
were infested with BCA in most citrus groves between May and August, largely due
to the activities of various species of coccinellids, the adults and larvae of which de
stroyed many colonies in their early stages. The following species of coccinellids have
been collected from BCA in Puerto Rico: Chilocorus cacti (L.), Cladis nitidula (F.), Co
elophora inaequalis (F), Coleomegilla innotata (Mulsant), C. sanguinea limbifer (L.),
Diomus sp., Egius platycephalus Mulsant, Hippodamia convergens (Guerin), Hy
peraspis sp., Olla v-nigrum (Mulsant), Procula feruuginea (Oliver), and Scymnus
(Schymnus) floralis (F.) (J. P. Michaud unpublished). The most abundant species were
C inaequalis and C. sanguinea. Small species such as Diomus sp., Hyperaspis sp. and
S. floralis prey only on early instars of BCA and appear to have only minimal impact
on aphid populations. C sanguinea is the most common coccinellid on BCA in the Do
minican Republic (Borb6n et al. 1992) and Cuba (Batista et al. 1995). It is also abun
dant feeding on BCA in Venezuela (Morales & Burandt 1985) and Brazil (Lara et al.
1977; Bartoszeck 1980). Additional coccinellid spp. recorded from BCA in Brazil in
clude Cleothera sp., Diomus sp., Exoplectra sp., and Scymnus sp. (Bartoszeck 1980).
Chagas et al. (1982) concluded that the coccinellids C sanguinea, Nephaspis sp.,
Stethorus sp. and Scymnus sp. in particular, were the most important predators of
BCA in Sao Paulo state and provided data on their seasonal abundance in citrus.
Other coccinellids collected from BCA in this study included Cleothera sp., Cycloneda
conjugata, Delphastus sp., Hyperaspis sp. Lindorus lophanthes, Neaporia sp., and
Pentilia sp. Valencia and Narciso Cardenas (1973) reported C. sanguinea and H. con
vergens as predators of BCA in Peru. Coccinellid species attacking BCA in Florida in
clude Brachiacantha decora (Casey), Brachiacantha dentipes (F.), C cacti, Chilocorus
stigma (L.), Coccinella septmpunctata L., C ineaqualis, Curinus coeruleus (Mulsant),
C s. sanguinea, Harmonia axyridis (Pallas), H. convergens, Hyperaspis ornatella Gor
don, 0. v nigrum, and Scymnus sp. (J. P. Michaud unpublished).
Kato (1969) listed Scymnus hilaris Motschulsky, Coccinella septepunctata bruckii
Mulsant, H. axyridis, Propulaeajaponica (Thunberg), Chilocorus kuwanae Silvestri
and Hyperaspisjaponica (Crotch) as coccinellid species attacking BCA in Japan. Ko
mozaki (1981) reported that S. hilaris was an important predator of BCA in Japan
and that its numerical response to increasing BCA populations was relatively good.
Nakao (1968) reported Stethorusjaponica Kamiya as another coccinellid species prey
ing on BCA in Japan, although Telsimia nigra Weise and C kuwanae were the most
abundant species in that study.
Maelzer (1978) states that Leis conformis (Boisduval.) is an important predator of
BCA in South Australia. Cheilomenes propinqua is listed by Catling (1970) as a coc
cinellid feeding on BCA in South Africa. Symes (1924) lists Chilomenes lunata F, Ale
sia bohemani Mulsant, A. geisha Gorh., Halyzia exiguenotata F, Lotis sp., and
Scymnus trepidulusWeise as coccinellids feeding on BCA in Rhodesia, noting that the


March, 1998

















Michaud: Review of Literature on Toxoptera citricida


first two species were most common. Abate (1988) lists Exochomus sp., Hyperaspis
senegalensis (Mulsant), Pharoscymnus madagassus (Weise) and Pharoscymnus sp. as
coccinellid predators of BCA in Ethiopia. Lever (1946) listed C. inaequalis and Coc
cinella repanda var. transversalis F as important predators of aphids in Fiji, include
ing BCA.
A study by Nickel & Klingauf (1985) in sub-tropical Argentina indicated that C.
sanguinea was the most important predator in that particular region. They measured
predator-prey ratios varying between 1-40 and 1-10, suggesting relatively good levels
of biological control which they attributed to the semi-natural conditions surrounding
their study sites. Recruitment of predators from outside citrus groves was judged to
be an important factor. The relatively low numbers of predators present in winter
months (May-August) was attributed to low rates of recruitment resulting from low
BCA population densities.
Lacewings (Neuroptera) are also predators of aphids that may contribute to sup
pression of their populations. Nakao (1968) reports Micromus novitus Navas and Eu
micromus numerous Navas (Hemerobiidae) as lacewings feeding on BCA in Japan.
Valencia and Narciso Cardenas (1973) collected Chrysopa sp. (now Chrysoperla sp.
chrysopidae) feeding on BCA in Peru. Chagas et al. (1982) reported the seasonal abun
dance of Chrysopa sp., Hemerobius sp. and Megalomus sp. found feeding on BCA in
Sao Paulo state, Brazil. Nusalala uruguaya (Hemerobiidae) has been recorded from
BCA in Brasil (Souza et al. 1989) and a Ceraeochrysa sp. (Chrysopidae) occurs on BCA
in Puerto Rico (J. P. Michaud unpublished), although it is rare. Abate (1988) reported
Anisochrysa boninensis (Okamoto) as a Chrysopid predator of BCA in Ethiopia. White
(1995) reported Chrysopa silvana Naval from BCA in Trinidad, although it was not
deemed a significant source of mortality. To date, Ceraeochrysa lineaticornis (Fitch),
and Micromus posticus (Walker) have been collected from BCA in Florida (J. P.
Michaud unpublished).
Several studies have suggested that BCA may be toxic to certain predators, or nu
tritionally inadequate for their successful development. Tao & Chiu (1971) reported
that 5 of 13 coccinellid species fed BCA, including C. repanda, suffered injury or
death, while the others remained unaffected. Souza et al. (1989) reported that larvae
of N uruguaya fed BCA did not survive to pupation and Tao & Chiu (1971) reported
similar findings for two species of Chrysopa. However, Venzon & Carvalho (1993)
found Toxoptera spp. (BCA?) to be a suitable diet for Cereaochrysa cubana (Hagen) in
Brasil and Ceraeochrysa sp. in Puerto Rico has been successfully reared to adult
stages on BCA (J. P. Michaud unpublished). Parker & Singh (1973) found that the coc
cinellids Chilocorus politus Muls., Coccinella arcuata F and Micraspis (Alesia) dis
color (F) all expressed a non-preference for BCA in feeding trials, although
Menochilus (Cheilomenes) sexmaculatus (F) did not. Morales & Burandt (1985) found
that C. sanguinea collected in Venezuela and fed BCA in the laboratory failed to com-
plete development. On the other hand, C. sanguinea and C. inaequalis collected in Pu
erto Rico developed normally and had good survival on an exclusive diet of BCA (J. P.
Michaud unpublished), suggesting that there may exist regional differences between
biotypes of predator species with respect to their ability to utilize BCA as food. Inter
estingly, no studies have found any indication of BCA toxicity to syrphids.
Ants are notorious for interfering with the beneficial activities of aphid predators
and/or parasites and BCA may sometimes benefit from a mutualistic association with
certain ant species. Observing ant and aphid populations in a citrus orchard in Japan,
Shindo (1972) concluded that the ant Pristomyrex pungens Mayr interfered with the
behavior of BCA predators (syrphids and coccinellids). Tao & Wu (1968) recommended
the removal of ant nests in the vicinity of BCA-infested trees in conjunction with
chemical treatments for control of the aphid. Bartoszeck (1980) recorded the ants Eu

















Florida Entomologist 81(1)


cryptocerus placidus (F Sm.) and Camponotus godmani Forel in association with BCA
in Brazil. Fire ants, Solenopsis invicta Buren, are often observed tending BCA in Flor
ida and Puerto Rico (J. P. Michaud unpublished) and are known to remove parasitized
aphids and mummies of L. testaceipes from aphid colonies (Vinson & Scarborough
1991). They have also been observed removing predatory larvae and dead aphids from
BCA colonies, and carrying live aphids to fresh, uninfested terminals (J. P. Michaud
unpublished). Other ant species observed tending BCA in Puerto Rico include Brach
ymyrmex obscurion Ford, Monomorium ebeninum Ford, Paratrechina longicornis (La
trielle), Pheidole fallax Mayr, Solenopsis globularia (F Smith), and Wasmannia
auropunctata (Roger) (J. P Michaud unpublished). In Florida, B. obscurion, Cam
ponotus sexguttatus (F), and Pseudomyrmex ejectus (F Smith) have been collected at
BCA colonies (J. P. Michaud unpublished).

ENTOMOPATHOGENS

Rondon et al. (1981) found the entomophagous fungus Verticillium lecanii (Zimm.)
Viegas to be the most important biological control agent during population outbreaks
of the BCA in the Carabobo and Yaracuy states of Venezuela in 1979 and 1980. The
predators reported as important in this study were C. sanguinea, O. gastrostactus and
Zelus spp. The authors noted that ideal ambient conditions for sporulation and ger
mination of the fungus (temperatures ranging from 18-24'C at a high relative humid
ity) were prevalent during the 2-yr period of the study. The fungus was reported to
survive unsuitable conditions in dried aphid mummies, and on aphid cadavers that
occur on suckering shoots growing in the interior of the tree where they are protected
from direct sunlight. The most suitable nutrient media for growing the fungus in the
laboratory were 523, nutrient agar, malt-agar, and PDA. These workers stated that
"the elevated pathogenicity on nymphs of different instars, adults, apterous and alate,
for which there was >80% mortality in the first 2 wk, prevented culmination of the in
sect's life cycle". However, the infection rate of 1.2% of colonies reported by White
(1995) in Trinidad is probably a more typical value for the natural occurrence of this
fungus on BCA. V lecanii has also been recovered from BCA in Puerto Rico, where it
appears to be a sporadic and localized source of aphid mortality (J. P. Michaud unpub
lished). De Romero and Romero (1985) evaluated mycelial growth and conidia yield of
V lecanii collected from BCA in Argentina on 2% potato agar. Batista et al. (1995) re
ported satisfactory results with applications of both V lecanii (Micotal-1 & Y-57
strains) and Paecilomyces fomosoroseus (INISA V strains) against the BCA in Cuba,
despite the fact that they observed no natural attacks by entomopathogenic fungi.
Samways & Grech (1986) found that the fungus Cladosporium oxysporum (Berk. and
Curt.) had considerable impact on BCA populations in field trials in South Africa,
which they attributed to the action of an unidentified toxin, rather than direct hyphal
growth. Other fungi are currently under evaluation for pathogenicity to BCA.

CTV TRANSMISSION

CTV is a closterovirus which causes multiple disease syndromes in citrus. The
most important are quick decline of trees on sour orange rootstock and stem-pitting
in susceptible scions irrespective of rootstock. Tristeza is possibly the most serious vi
rus disease of citrus world-wide and yet it is poorly understood. It is not yet possible
to attribute particular symptoms on a particular citrus cultivar to specific viral se
quences, nor is it known which sequences influence transmissibility by its most effi
cient insect vector, the BCA. Meneghini (1946) in Brazil presented the first evidence
of CTV transmission by the BCA. Meneghini (1948) showed semi-persistent transmis


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Michaud: Review of Literature on Toxoptera citricida


sion of CTV; viruliferous BCA starved for 48 h lost their ability to transmit the virus,
while a 24 h starvation period did not affect the percentage of trees infected. This was
later confirmed by Costa & Grant (1951). Kennedy et al. (1962) suggested that
tristeza virus was probably stylet borne. Retuerma & Price (1972) claimed that both
acquisition and transmission of CTV by BCA can occur within a few seconds of feeding
and concluded this was proof that CTV was stylet borne, a conclusion subsequently
questioned by others. Singh (1978) successfully achieved CTV transmission feeding
leaf and bark extracts to BCA through a stretched parafilm membrane and suggested
that CTV may not be a typical stylet-borne virus, but may also be transmitted in a cir
culative, non-propagative manner. Such bimodal transmission was also suggested by
Lim & Hagedorn (1977) but this explanation is not generally accepted and further ev
idence of short probing transmission is required (Bar-Joseph et al. 1979). The fact that
CTV is phloem-limited makes transmission by brief probing less likely. The current
consensus is that CTV transmission best fits the semi-persistent mode (Bar-Joseph et
al. 1979; Raccah & Singer 1987) in which the virus is acquired and transmitted by
aphids with feeding times ranging from several minutes to several hours, but usually
not by brief probing.
Historically, introduction of the BCA has invariably resulted in the accelerated
spread of CTV throughout entire citrus growing regions, the best example being the
virtual destruction of the citrus industry in Brazil and Venezuela during the 1970's,
most of which was rooted on sour orange (Lee et al. 1995). A number of studies have
shown that the BCA is a relatively efficient vector of CTV when compared with other
aphids that feed on citrus. Schwartz (1965b) observed that infections of trap plants
with BCA were closely correlated with the numbers of BCA collected from the plants.
In the Philippines, Celino et al. (1966) showed that BCA was a more effective vector
than either T aurantii or A. _-. ,-- Sharma (1989) tested 20 isolates of CTV and
found that 12 were most efficiently transmitted by BCA, 5 by A. ,. - and 3 by
Myzus persicae. Yokomi and Damsteegt (1991) quantified the efficiency with which
the BCA transmitted CTV in comparison to A. and found the former species
to be significantly more efficient. Balaraman & Ramakrishnan (1979) showed that
BCA was more efficient than either A. , --- or T aurantii at transmitting the 2
strains of CTV they tested, and that higher percentage transmission occurred with
the severe strain than with the mild strain. The authors found that a minimum of 15
viruliferous aphids/plant were required for 100% transmission when feeding periods
were 24 h each for acquisition and transmission.
A number of studies have shown that variant strains of CTV differ in their trans
missibility by aphids (Bar-Joseph & Loebenstein 1973; Raccah et al. 1978; Raccah et
al. 1980). Sharma (1989) showed that severe strains of CTV he tested were transmit
ted by BCA with higher efficiency than the mild strains; acquisition periods were
shorter and retention periods were longer. The fact that citrus varieties vary with re
gard to their suitability for CTV acquisition by BCA further complicates the picture
(Bar-Joseph et al. 1979).
A concise review of the literature on CTV transmission by aphids, including a list
of infectivity studies on BCA and A. ., --- is provided by Roistacher & Bar-Joseph
(1987) (reproduced in Roistacher & Bar Joseph 1989). Bar-Joseph et al. (1983) provide
a review of the epidemiology and control of CTV, as does Lee (1994). Bar-Joseph et al.
(1989) and Lee & Rocha-Pena (1992) are both comprehensive reviews of the history of
CTV, its host range, diagnosis, and molecular characterization.
In addition to CTV, the BCA has been implicated in vectoring other plant viruses,
although some reports are questionable and lack confirmation. Potyviruses transmit
ted by BCA include yam mosaic virus (Thouvenel & Fauquet 1979), soybean mosaic
virus (Halbert et al. 1986), sugar cane mosaic virus (reported as mosaic of abaca,

















Florida Entomologist 81(1)


Musa textilus, by Gavarra & Eloja (1965)) and chili veinal mottle virus (Ong et al.
1979). BCA did not transmit potato virus Y or pepper veinal mottle virus, other vi
ruses infecting chilli peppers, Capsicum annum (Gowda & Reddy 1989). In the same
series of experiments, BCA failed to transmit cucumber mosaic cucumovirus, which,
although not a potyvirus, is non-persistently transmitted by many aphid species.
Using electron microscopy, Maharaj & da Graca (1988) found virions of citrus vein
enation virus, a probable luteovirus, in the hindgut lumen and accessory salivary
glands of BCA and subsequently (Maharaj & da Graca 1989), showed transmission by
the aphid. Persistent transmission of citrus vein enation virus has been demonstrated
in both A. ,- --- and M. persicae (Hermoso de Mendoza et al. 1993). Portillo &
Befatena (1986) claimed that BCA was capable of transmitting citrus psorosis virus
to various Citrus spp. in Argentina. However, the assays were based primarily on
symptoms and this conclusion has yet to be confirmed by molecular studies. Protacio
(1965) reported that BCA can potentially transmit the agent of cadang-cadang dis
ease to coconut palms, but this disease is now thought to be caused by a viroid and
there is no evidence for insect transmission of viroids.
Broadbent & Fraser (1976) concluded that BCA was not responsible for vectoring
the organism that causes citrus dieback in Australia. Similarly, BCA was shown not
to be responsible for vectoring citrus leaf mottle disease in the Philippines (Salibe &
Cortez 1967), or the greening disease of citrus that is vectored by Trioza erytreae
(McLean & Oberholzer 1965).

MONITORING AND CONTROL

Sticky traps and pan traps have both been used for monitoring flight activity of the
BCA, and are more economical than suction traps in terms of capital outlay. However,
sticky traps are attractive to many insects and must be replaced frequently. Further
more, aphids caught in such traps inevitably require special solvents to remove and
are usually badly damaged, making identification difficult. Pan traps yield specimens
in better condition but also need to be emptied on a regular basis and are prone to
flooding during periods of heavy rain. Furthermore, it should be kept in mind that
traps only monitor the flight activity of alates, provide little information on the sur
vival or location of aphids in citrus groves, and are not a substitute for effective survey
techniques, i.e. physically searching groves for established colonies.
Alate BCA are not strong fliers and few fly far from their parent colony (Gottwald et
al. 1995). Gavarra & Eastop (1976) obtained better catches of BCA in yellow Moericke
trays at 152 cm height than they did in trays at ground level. Consequently, optimal
placement of traps is probably above ground level, but lower than the height of sur
rounding trees. Lara et al. (1976) used water traps to compare the attractiveness of var
ious colors to a number of different insects in citrus. In general, they found yellow and
white to be the most attractive to all species, including the BCA and its predators C.
sanguinea and Chrysopa sp. However, Schwarz (1965c) found that the relative attrac
tiveness of yellow and green to BCA changed seasonally, and varied from year to year.
The decision whether or not to apply an insecticide to a BCA infestation will be af
fected by many factors, primarily the type of trees infested. These can be arranged in
order of tolerance (lowest to highest): (1) budwood sources, (2) nursery stock, (3)
newly-planted saplings and, (4) mature, producing trees (Knapp et al. 1996). Given
the Budwood Certification Program presently in effect in the state of Florida which
regulates the maintenance of budwood sources free of severe strains of CTV, the first
two categories demand a very low tolerance of BCA infestations. Such trees are best
protected either by screened enclosures, soil applications of systemic insecticides, or
a combination of both. Alternatively, geographic isolation of budwood groves in non


March, 1998

















Michaud: Review of Literature on Toxoptera citricida


citrus producing areas might provide a more permanent solution. Heavy infestations
on young trees may impede their growth (Hely 1968) and the tolerance level for BCA
on saplings is consequentially lower than that for mature trees. There is some indica
tion that BCA infestations can reduce flowering and fruit set (Hall 1930; Smit 1934;
Hely 1968), and occasionally lead to dropping of flower buds and young fruit on a large
scale (Symes 1924), although good quantitative data is lacking. This suggests that a
lower injury threshold may exist for trees in flower and early stages of fruit set. Apart
from these circumstances, tolerance levels for BCA infestations on producing trees
will likely vary with the local incidence of severe CTV strains capable of producing de
cline on sour orange-rooted trees or stem-pitting on scions of orange or grapefruit, and
with their proximity to susceptible trees. Otherwise, there is little indication of direct
damage to mature trees, even under heavy feeding pressure.
The earlier reports of successful chemical control of BCA usually recommended fo
liar sprays of lime-sulphate, nicotine sulphate, or soap and nicotine. Hall (1930) rec
ommended spraying winter colonies to reduce populations prior to spring flush. Tao &
Tan (1961) recommended chemical treatment of CTV infected trees, which tend to
bloom and flush early, in order to prevent migration of aphids to healthy trees which
flush later. Young resets typically flush earlier than mature trees and could be in
spected for BCA prior to the flush of mature trees and spot-treated as required to pre
clude outbreak populations when flush availability increases. Ideally, growers should
attempt to prevent BCA infestations developing on CTV infected trees, as opposed to
CTV susceptible, uninfected trees, as there is no evidence to suggest that even the
best systemic compounds can protect against CTV transmission. In practise, this will
only be possible for growers with good information on the location of CTV infections
in their groves. Foliar formulations of various insecticides can be used to kill aphids
on contact, but they can also be expected to have greater impact on non-target and
beneficial insects than systemic materials. Consequently, their use should be limited
to spot applications of heavily infested areas only.
Calza et al. (1968) evaluated 9 organphosphate and carbamate compounds against
BCA in Sao Paulo, Brazil. Tao & Wu (1968) painted tree trucks with a 30% aqueous
solution of the systemic insecticide monocrotophos (Azodrin) and found it more effec
tive against BCA than dimethoate, vamidothion, or formothion when applied in this
manner. In a later study (Tao & Wu 1969) they found that 2 spring applications of
monocrotophos at 12.5% a.i. gave good control of BCA and had minimal impact on nat
ural enemies in the grove. Buitendag & Bronkhorst (1986) found monocrotophos to be
without phytotoxicity to citrus trees and calculated application rates for control of
BCA on trees of different sizes. These authors also calculated rates for trunk applica
tions of Dicrotophos against BCA (Buitendag & Bronkhorst 1984) and described a
method for injecting systemic insecticides directly into trees (Buitendag &
Bronkhorst 1980). While systemic compounds may generally have lower impact on
natural enemies, their use as granular formulations or soil drenches on producing
trees is often narrowly restricted to particular seasons to minimize contamination of
ground water runoff. Foliar applications should be considered a last resort, unless
compounds can be selected which minimize impact on beneficial insects within the
grove. For example, Portillo (1977) showed that various concentrations of pirimicarb
were effective against BCA in laboratory tests, and relatively low in toxicity to C. san
guinea. In addition, spot treatments of heavily infested trees or blocks, as opposed to
blanket treatment of entire groves, would provide refuges for natural enemy popular
tions and speed their recolonization of treated areas.
Koli et al. (1978) tested 0.05% sprays of 6 insecticides against BCA on citrus seed
lings in India and found that phosphamidon gave the best initial knockdown and the
most prolonged activity. Trevizoli & Gravena (1979) compared trunk and foliar sprays

















Florida Entomologist 81(1)


of ethiofencarb, dimethoate, malathion and pirimicarb and found that all methods
and materials were effective against BCA. However, they found that trunk sprays of
pirimicarb and dimethoate had less impact on predator populations (C. sanguinea
and Chrysopa sp.) than did foliar sprays.
Milne & de Villiers (1977) determined application rates for delivery of dimethoate
by microjet and drip irrigation that gave season-long control of BCA and other ho
mopterans. Milne (1977) protected bagged nursery seedlings from BCA for a period of
5-6 wk with a single soil-drench application of dimethoate (40% EC, 1.0 ml/bag). Bui
tendag & Bronkhorst (1983) describe a method for using bands to hold Temik gran
ules against the trunks of trees. This method provided good control of BCA on young
citrus trees, but its effectiveness declined when trunk diameter increased above 125
mm. Shevale et al. (1987) found that foliar applications of phosphamidon, dimethoate,
methyl demeton, monocrotophos and quinalphos (each at 0.025% conc.) all provided
>95% reduction of BCA within 24 h of treatment, although phosalone did not. Signif
icant recolonization by BCA was evident in all treatments by day 15. Under the par
ticular conditions of this study, phosphamidon and dimethoate were judged to be the
most cost-effective.
Jothi et al. (1990) obtained control of BCA on lime in India with foliar application
of botanical insecticides. They found that oils of Mahua (Bassia latifolia) and pon
gamia (Pongamia pinnata) at 1% and seed extracts of pongamia and neem (Aza
dirachta indica) at 2% applied early in the flush cycle gave adequate control, and
resulted in BCA populations significantly lower than controls after 7 days. Field trials
conducted in Puerto Rico by Yokomi et al. (1995) indicate that foliar treatments of
ethion (2.5 lb ai/A) + oil (5 gal), ethion + abamectin (2.5 lb and 1.1 gal ai/A, respect
tively) + oil (5 gal), and pirimicarb (0.25 lb ai/A), and acephate (1.0 lb ai/A) all pro
duced close to 100% mortality of BCA, whereas chlorpyriphos (2.5 lb ai/A) yielded 88%
mortality Knapp et al. (1996) provide current recommendations for management of
BCA in Florida citrus, budwoodd sources, nurseries, and producing trees), and include
a list of currently approved materials.

ACKNOWLEDGMENTS

The author wishes to thank C. Bergh, C. McCoy, and especially R. Brlansky whose
review and commentary improved the manuscript. S. E. Halbert assisted in compiling
the host list and made other contributions to the MS. Thanks are also due to G. Evans,
L. Davis Jr., R. Gordon, L. A. Stange, M. Thomas, and H. Weems for their assistance
with specimen identifications. Special thanks to P Russ for her help in obtaining the
more obscure references. This work was funded by Grant No. 727342212 from USDA
APHIS. University of Florida, Institute of Food and Agricultural Sciences Manuscript
Transmittal No. R-05697.

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Aphididae) and their natural enemies in Citrus orchards in the Eastern Medi
terranean region. Turkiye III. Biyolojik Mucadele Knogresi Bildirileeri, 25-28
Ocak 1994, Ege Universitesi Ziraat Fakultesi, Bitki Koruma Bolumu, Izmir.
1994, 1-12. (in Turk., Eng. sum.).


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Wetterer et al.: Ecology of a Costa Rican Leaf cutting Ant


FORAGING AND NESTING ECOLOGY OF ACROMYRMEX
OCTOSPINOSUS (HYMENOPTERA: FORMICIDAE) IN A COSTA
RICAN TROPICAL DRY FOREST

JAMES K. WETTERER,1 DANIEL S. GRUNER AND JORGE E. LOPEZ3
'Center for Environmental Research & Conservation, Columbia University
New York, NY 10027

Department of Zoology, University of Hawaii, Honolulu, HI 96822

3Department of Ecology and Evolution, University of Chicago, Chicago, IL 60637

ABSTRACT

Leaf cutting ants (Acromyrmex sp. and Atta sp.) in Costa Rica show many intra
and interspecific differences in ecology. Recent taxonomic studies question whether
the Acromyrmex octospinosus populations on the Pacific and Atlantic slopes of Costa
Rica are a single species. We therefore examined the foraging and nesting ecology of
A. octospinosus in the tropical dry forest of Palo Verde National Park on the Pacific
slope of Costa Rica and compared our findings with published data on the ecology of
A. octospinosus in the tropical moist forest of La Selva Biological Station on the At
lantic slope. The Pacific A. octospinosus foraged primarily on the leaves of herbs and
other small plants, fallen leaves, fruit, flowers, and insect frass, but does not cut the
leaves of large trees. Worker size distribution within colonies was bimodal with only

















Florida Entomologist 81(1)


the larger workers leaving the nest to forage. Nests were shallow and generally under
a few centimeters of organic debris at the base of trees and woody shrubs or in crev
ices. The foraging and nesting ecology of the Pacific A. octospinosus appeared to be
very similar to that of the Atlantic A. octospinosus, except that the Pacific ants col
elected considerable amounts of insect frass (11% of all loads), whereas the Atlantic
ants had no recorded loads of frass. This difference in selectivity, however, may have
been due simply to seasonal differences in availability of frass at the sites.
Acromyrmex octospinosus was the only species of leaf cutting ant found at Palo
Verde. The vertisol soil of the area, which has very poor drainage when wet and cracks
deeply when dry, may not be suitable for major pest species of leaf cutters in Costa
Rica, Atta cephalotes and Atta colombica, which excavate nests deep underground.

Key Words: Atta, foraging selectivity, Palo Verde, pest ants

RESUME

Las hormigas podadoras (Acromyrmexsp. y Atta sp.) en Costa Rica muestran mu
chas diferencias intra e interespecificas en ecologia. Estudios taxon6micos recientes
ponen en duda la noci6n que poblaciones de Acromyrmex octospinosus en los flancos
Orientales y Occidentales de Costa Rica sean una sola especie. Por lo tanto, nosotros
examinamos la ecologia de alimentaciun y anidamiento de A. octospinosus en el bos
que seco tropical del Parque Nacional Palo Verde en el flanco occidental de Costa Rica,
y comparamos nuestros resultados con datos previamente publicados sobre la ecologia
de A. octospinosus en el bosque humedo tropical de la Estaci6n Biol6gica La Selva en
el flanco oriental. La alimentaci6n de A. octospinosus en el lado occidental consisti6
principalmente de hojas de hierbas y otras plants pequenas, hojas caidas, frutas, flo
res y excrementos de insects, pero no cortan hojas de arboles grandes. La distribu
ci6n del tamano de las obreras en la colonia es bimodal, y solo las obreras grandes
salen de la colonia para recoger alimentos. Los nidos son poco profundos y por lo ge
neral estan bajo unos cuantos centimetros de material organica al pie de arboles y ar
bustos, o en grietas. La ecologia de alimentaci6n y anidamiento de A. octospinosus en
el lado occidental parece ser muy similar a la de A. octospinosus en el lado oriental, ex
cepto que las hormigas en el lado occidental recogen cantidades considerable de ex
cremento de insects (11% de todas las cargas), mientras que las hormigas en el lado
oriental no han sido observadas cargando excremento de insects. Esta diferencia en
selectividad, sin embargo, puede ser causada por diferencias en disponibilidad de ex
cremento de insects en diferentes estaciones entire las localidades. Acromyrmex oc
tospinosus fue la fnica especie de hormiga podadora encontrada en Palo Verde. El
suelo vertisol de esa area, que tiene muy mal drenaje cuando esta mojado y que forma
rajaduras hondas cuando esta seco, puede no ser adequado para otras species dani-
nas de hormigas podadoras en Costa Rica, Atta cephalotesy Atta colombica, las cuales
excavan nidos profundos.





Fungus-growing ants (Myrmicinae; Attini) are unique among ants in their habit of
cultivating a symbiotic fungus for food. All attine ants are obligately dependent on
their fungus. In other aspects of their ecologies, however, different species of attines
vary greatly (Weber 1972, H6lldobler & Wilson 1990). Ants of the nine "lesser" genera
(Cyphomyrmex, Mycetosoritis, Mycetophylax, Mycocepurus, Mycetarotes, Myrmicoc
rypta, Apterostigma, Sericomyrmex, and Trachymyrmex) typically collect insect frass,
dead insects, or small pieces of fallen plant material to use as substrate for their fun
gal gardens. They tend to have small and inconspicuous colonies (fewer than 5000 in
dividuals), with relatively monomorphic workers. In contrast, ants belonging to two


March, 1998

















Wetterer et al.: Ecology of a Costa Rican Leaf cutting Ant 63

genera of attines, Acromyrmex and Atta, often depend on harvesting leaves for their
fungal gardens and consequently are commonly called leaf cutting ants. Leaf cutting
ant colonies can grow to include many thousand to several million highly-polymorphic
workers. Many leaf cutters, particularly Atta species, are major agricultural pests.
Earlier studies have found striking differences in the foraging and nesting ecology
of Acromyrmex octospinosus (Reich), Acromyrmex volcanus (Wheeler), Acromyrmex
coronatus (Fabricius), and Atta cephalotes (L.), the four species of leaf cutting ants
found on the Atlantic slope of Costa Rica (Wetterer, 1991, 1993, 1994a, b, 1995). Ac
romyrmex octospinosus and A. volcanus colonies forage primarily on small herbs and
fallen leaves, fruits, and flowers (Wetterer 1991, 1993). These colonies produce two
distinct size castes of workers (Wetterer, unpublished). The minima workers stay in
side the nest, tending the fungus garden and brood, while the relatively monomorphic
maxima workers leave the nest to forage. In A. coronatus colonies and small A. ceph-
alotes colonies, workers primarily cut the soft leaves of herbaceous plants (Wetterer
1994a, 1995). These colonies produce a narrow range of small workers, the largest of
which are just big enough to cut soft vegetation efficiently (Wilson 1983, Wetterer, un
published). In large A. cephalotes colonies, workers primarily attack the leaves and
flowers of trees (Cherrett 1968, 1972; Rockwood & Hubbell 1987; Vasconcelos 1990;
Wetterer 1994b). These colonies produce an extremely broad continuous size-range of
workers (Stradling 1978; Wilson 1983). A wide range of medium-size workers forage,
with the larger of these cutting thicker and tougher vegetation (Nichols-Orians &
Schultz 1989; Wetterer 1994b).
Recent taxonomic research, based on morphological characters and allozyme poly
morphisms, has raised questions as to whether the A. octospinosus on the Pacific and
Atlantic slopes of Costa Rica are a single species (J. Longino, T Schultz, & K.
Boomsma, personal communication). Because earlier studies indicated marked inter
specific ecological differences among leaf-cutting ants, we compared the foraging and
nesting ecology of Pacific and Atlantic A. octospinosus. We also examined the question
as to why A. octospinosus was the only leaf cutting ant species present at our study
site in Palo Verde National Park.


METHODS

We studied foraging selectivity and nesting habits of Acromyrmex octospinosus col
onies at the start of the wet season (June 1996) in tropical dry forest of Palo Verde Na
tional Park, Guanacaste Province, Costa Rica. We worked in the area around Palo
Verde Biological Station (10 19'N, 85 21'W; elevation 10 m), operated by the Organi
zation for Tropical Studies (see Janzen 1983 for a site description). We conducted our
study during daylight hours, when most A. octospinosus colonies were actively forag
ing. On an earlier visit to Palo Verde in the dry season (January 1996), there was no
diurnal foraging by A. octospinosus (J. Wetterer, personal observation).
Through extensive searches along hiking trails and roads around Palo Verde, we
located seventeen A. octospinosus colonies. At a nearby open pasture site, Sitio Mojal,
we collected data on one additional A. octospinosus colony (colony 12), making a total
of eighteen colonies. We found no other leaf-cutting ant colonies at the site, although
we did find a single live alate Atta cephalotes queen. We explored the area for several
kilometers in different directions, but never located any A. cephalotes colonies.
At each A. octospinosus colony, we collected laden foragers from along their forag
ing trails. To help ensure a representative sample, we collected laden foragers at ten
second intervals as they passed a designated point on their trail, or if there were few
foragers, we collected consecutive foragers. We used data from twelve colonies in our

















Florida Entomologist 81(1)


foraging selectivity analysis. At four large A. octospinosus colonies, we collected 25 for
agers from each of the two main trails. From six smaller colonies, we collected 25 for
agers for each colony. At two very small colonies, we collected only fourteen workers
from one colony and eleven from the other, because no more foragers came in a period
of several hours. At six other small colonies we collected none or only one forager due
to lulls in foraging activity that seemed to be associated with hot sunny weather. We
did not include these collections in our foraging selectivity analysis.
We classified each load as fresh (soft, pliant, and green) or fallen (dry or yellowed)
leaf material (fragment or whole leaf), herb section (stem or stem with leaves, leaf
buds, or flowers), flower (part or whole), fruit (part or whole berry), insect frass, or
"other." Whenever possible, we located and identified the original source of each load.
At each colony we followed laden foragers in order to locate their nests. We par
tially excavated nests to confirm the location of their fungus garden. In addition, we
collected one complete colony.
Voucher specimens from this study have been deposited at the National Museum
of Natural History, Washington D.C.

RESULTS


Foraging selectivity

Acromyrmex octospinosus foragers carried a wide variety of vegetable matter (Ta
ble 1). There were great differences among the twelve colonies and even between
trails of the same colony (Table 1). The fresh leaf material that the ants cut came pri
marily from leaves of herbs or from tree seedlings. For example, in the colony with the
highest proportion of fresh leaf fragments (colony 8), all leaf material came from small
Acacia seedlings growing in the area. Foragers also commonly cut pieces of fallen
leaves, sections of herbs (herb stems and stems with leaves, leaf buds, or flowers),
fruits, petals, and flower buds, plus variable amounts of other types of plant material
petioless, seeds, bark, sticks, and wood slivers). At several colonies, foragers carried
insect frass, apparently from caterpillars. Although we once found A. octospinosus for
agers with fruit fragments descending a small tree, we never found foragers cutting
the leaves of large trees.
The general types of material gathered by the Pacific A. octospinosus foragers was
very similar to those gathered by the Atlantic A. octospinosus foragers, except that the
Pacific A. octospinosus foragers harvested less fruit and more insect frass (Table 2).


Nesting Habits

We located the nests of all eighteen A. octospinosus colonies. All nests were very
shallow and required little excavation. Twelve nests were directly in contact with a
tree or woody shrub: eight under organic debris at the base of trees or woody shrubs,
two under organic debris on top of tree buttress roots, and two in tree crevasses (one
and two meters above the ground). Three nests were associated with artificial sub
states: one under roofing slates piled in a gully, one between two pieces of sheet metal
on the forest floor, and one in the cracked cement foundation of a building. Finally, two
nests were under organic debris in open soil areas and one was in a crevice of a rock
outcrop.
Within the A. octospinosus nests there was a noticeable bimodal worker size-dis
tribution with two distinct size castes of workers. Only the large workers left the nest
to forage.


March, 1998

















Wetterer et al.: Ecology of a Costa Rican Leaf cutting Ant 65

TABLE 1. FORAGING SELECTIVITY BY TWELVE COLONIES OF ACROMYRMEX OCTOSPINO
SUSIN PALO VERDE NATIONAL PARK ("A" AND "B" REFER TO TWO TRAILS FROM
THE SAME COLONY).

fresh fallen herb
Colony (n) leaf leaf part fruit flower frass other

1 A (25) 8 7 0 8 2 0 0
B (25) 3 1 0 18 2 0 1 (bark)
2 A (25) 4 8 8 0 3 2 0
B (25) 0 0 0 9 0 16 0
3 A (25) 6 0 0 0 1 14 4 (seeds)
B (25) 6 12 4 0 0 1 2 (leaf stipules)
4 (25) 5 4 3 6 7 0 0
5 (25) 10 5 1 1 3 2 3 (soil)
6 (25) 4 0 0 17 0 4 0
7 (25) 2 21 0 0 1 1 0
8 (25) 22 1 1 0 1 0 0
9 (25) 1 0 0 0 23 0 1 (leaf stipule)
10 (14) 0 4 0 0 9 0 1 (leaf stipule)
11 (11) 3 2 0 0 5 0 1 (wood sliver)
12 A (25) 14 4 4 0 0 0 3 (2 sticks, 1 seed)
B (25) 18 1 3 1 0 2 0

Total (375) 106 70 24 60 57 42 16


DISCUSSION

The foraging ecology of the Pacific Acromyrmex octospinosus appears to be very
similar to that of the Atlantic Acromyrmex octospinosus (Table 2; Wetterer 1991). The
colonies from both areas produce two distinct size castes of workers. The smaller
workers stay inside the nest, tending the fungus garden and brood, while the large
workers forage. Both Pacific and Atlantic Acromyrmex octospinosus show seasonal
variation in foraging activity, with primarily diurnal foraging in the wet season and
primarily nocturnal foraging in the dry season (Wetterer 1991). Both also primarily
cut the leaves and other parts of small herbs and scavenge on fallen leaves, fruits, and
flowers (Wetterer 1991). The Pacific ants, however, harvested less fruit and more in
sect frass than was recorded for the Atlantic ants (Table 2). The great variability in se
lectivity both among colonies and between trails of the same colony suggests that A.
octospinosus foragers are opportunists and shift their selectivity based on resource
availability (Table 2, see also Lewis 1975, Wetterer 1991). Rather than a strict "leaf
cutting" ant, A. octospinosus seems to be a scavenger of small herbs, fallen vegetation,
and other organic material.
Many genera of "lesser" fungus-growing ants commonly collect insect frass as a
substrate for growing fungus (Weber 1972, HOlldobler & Wilson 1990), though this is
rarely observed in leaf cutting ants (generally << 1% of loads, personal observation).
Frass would appear to be well suited for fungal growth, but probably rarely occurs in
great enough quantities to support large colonies of leaf-cutting ants. At the time of

















Florida Entomologist 81(1)


TABLE 2. FORAGING SELECTIVITY BY COLONIES OF THE PACIFIC ACROMYRMEX OCTOS
PINOSUS COMPARED WITH THAT OF COLONIES OF THE ATLANTIC ACROMYRMEX
OCTOSPINOSUS (WETTERER 1991), ACROMYRMEX VOLCANUS (WETTERER
1993), AND ACROMYRMEX CORONATUS (WETTERER 1995), AND SMALL COLO
NIES OF ATTA CEPHALOTES (WETTERER 1994A).

% fresh % fallen % herb % % %
Species (n) leaf leaf part flower fruit other

A. octospinosus
Pacific (375) 28 19 6 16 15 15
Atlantic (275) 23 17 9 19 27 5

A. volcanus (239) 33 8 15 33 6 7
A. coronatus (380) 82 11 2 3 1 2
A. cephalotes (200) 97 0 0 1 1 1



our study, the start of the wet season, there was a population explosion of caterpillars
at Palo Verde, resulting in a hyperabundance of caterpillar frass.
The nesting habits of the Pacific A. octospinosus also appears to be very similar to
that the Atlantic A. octospinosus, as well as those of other Acromyrmex species (Weber
1945; Wetterer 1991, 1993). At La Selva Biological Station, on the Atlantic slope,A. octos
pinosus most commonly nests under organic matter at the base of trees (Wetterer 1993).
A similar pattern of nesting for A. octospinosus has also been reported by Weber (1945).
In contrast, A. cephalotes colonies excavate nests deep underground (Weber 1972).
The question arises as to why the two major pest species of leaf-cutting ants in
Costa Rica, Atta cephalotes and Atta colombica Guerin, are absent at Palo Verde, but
are common in other dry forest areas of similar climate and vegetation in western
Costa Rica, e.g., Santa Rosa National Park, where they co-occur with A. octospinosus
(Rockwood 1973; J. Wetterer, personal observation). The presence of an alate Atta
queen indicates they are not excluded due to limitations of dispersal. Instead, a pos
sible explanation may lay in the soil of Palo Verde, a vertisol with a high proportion
of montmorillonite clay (E. Olson, personal communication). This soil absorbs water
into its lattice when wet, increasing its volume dramatically (Fanning and Fanning
1989). When the wet soil swells, pore spaces are squeezed out, resulting in very poor
drainage and aeration. When the soil dries, it contracts and meter deep cracks form.
Surface material fills these cracks causing soil "inversion," hence the name vertisol.
Vertisol soil may not be suitable for deeply excavated nests such as those of most Atta
species, due to insufficient aeration in the wet season and excessive exposure in the
dry season (E. Olson, personal communication). The superficial nests of A. octospino
sus may not suffer from these problems. The soil type may also indirectly explain the
insect frass collected by A. octospinosus, because many of the lesser fungus-growing
ants that collect insect frass also have deep nests (Wetterer, personal observation),
and thus may be absent at Palo Verde. Surveys for leaf-cutting ants and other fungus
growing ants in areas of different soil types are needed to test these hypotheses.
In conclusion, although taxonomic studies may distinguish differences between
the Pacific and Atlantic A. octospinosus, we could find no notable ecological differences
in foraging or nesting ecology between sites. This result is particularly surprising con
sidering the distinct differences in vegetation between the Pacific dry forest and the
Atlantic rain forest of Costa Rica (see Janzen 1983).


March, 1998

















Wetterer et al.: Ecology of a Costa Rican Leaf cutting Ant 67

ACKNOWLEDGMENTS

We thank M. Wetterer and E. Olson for comments on this manuscript; the students
and faculty of the OTS 96-3 course for field assistance and friendship; and especially
E. Olson for inviting us to join the course and making this study possible. Financial
support was provided by the Organization for Tropical Studies, Columbia University,
College of Natural Sciences and Department of Ecology, Evolution and Conservation
Biology at the University of Hawaii, the University of Chicago, and the US Depart
ment of Education (Gann Fellowship P200A40413 to JEL).


REFERENCES CITED

CHERRETT, J. M. 1968. The foraging behavior ofAtta cephalotes L. (Hymenoptera, For
micidae) I. Foraging pattern and plant species attacked in tropical rain forest.
J. Anim. Ecol. 37: 387-403.
CHERRETT, J. M. 1972. Some factors involved in the selection of vegetable substrate
by Atta cephalotes (L.) (Hymenoptera: Formicidae) in tropical rain forest. J.
Anim. Ecol. 41: 647-660.
FANNING, D. S., AND N. C. B. FANNING. 1989. Soil: morphology, genesis, and classifi
cation. John Wiley & Sons, NY.
HOLLDOBLER, B., AND E. O. WILSON. 1990. The Ants. Harvard University Press, Cam
bridge, MA.
JANZEN, D. 1983. Costa Rican Natural History. University of Chicago Press, Chicago,
IL.
LEWIS, T 1975. Colony size, density and distribution of the leaf cutting ant, Ac
romyrmex octospinosus (Reich) in cultivated fields. Trans. R. Entomol. Soc.
London 127: 5164.
NICHOLS-ORIANS C. M., AND J. C. SCHULTZ. 1989. Leaf toughness affects leaf harvest
ing by the leaf cutter ant, Atta cephalotes (L.) (Hymenoptera: Formicidae). Bio
tropica 21: 80-83.
ROCKWOOD, L. L. 1973. Distribution, density, and dispersion of two species of Atta
(Hymenoptera: Formicidae) in Guanacaste Province, Costa Rica. J. Anim. Ecol.
42: 803-817.
ROCKWOOD, L. L., AND S. P. HUBBELL. 1987. Host plant selection, diet diversity, and
optimal foraging in a tropical leafcutting ant. Oecologia 74: 55-61.
STRADLING, D. J. 1978. The influence of size on foraging in the ant, Atta cephalotes,
and the effect of some plant defense mechanisms. J. Anim. Ecol. 47: 173-188.
VASCONCELOS, H. L. 1990. Foraging activity of two species of leaf cutting ants (Atta)
in a primary forest of the central Amazon. Insect. Soc. 37: 131-145.
WEBER, N. A. 1945. The biology of the fungus-growing ants. Part VIII. The Trinidad,
B.W.I., species. Rev. Entomol. 16: 188.
WEBER, N. A. 1972. Gardening ants: the attines. American Philosophical Society, Phil
adelphia, PA.
WETTERER, J. K. 1991. Foraging ecology of the leaf cutting ant, Acromyrmex octospi
nosus, in a Costa Rican rain forest. Psyche 98: 361 371.
WETTERER, J. K. 1993. Foraging and nesting ecology of a Costa Rican leaf cutting ant,
Acromyrmex volcanus. Psyche 100: 6576.
WETTERER, J. K. 1994a. Ontogenetic changes in forager polymorphism and foraging
ecology in the leaf cutting ant, Atta cephalotes. Oecologia 98: 235-238.
WETTERER, J. K. 1994b. Forager polymorphism, size-matching, and load delivery in
the leaf cutting ant, Atta cephalotes. Ecol. Entomol. 19: 5764.
WETTERER, J. K. 1995. Forager size and ecology of Acromyrmex coronatus and other
leaf cutting ants in Costa Rica. Oecologia 104: 409-415.
WILSON, E. O. 1983. Caste and division of labor in leaf cutter ants. IV. Colony ontog
eny of A. cephalotes. Behav. Ecol. Sociobiol. 14: 5560.

















Florida Entomologist 81(1)


TWO NEW SPECIES OF LEPTOHYPHES
(EPHEMEROPTERA:LEPTOHYPHIDAE) FROM ECUADOR

T. Q. WANG,' R. W. SITES,' AND W. P. MCCAFFERTY2
'Enns Entomology Museum, Dept. of Entomology, University of Missouri-Columbia
Columbia, MO 65211

2Dept. of Entomology, Purdue University, West Lafayette, IN 47907


ABSTRACT

Leptohyphes liniti New Species and Leptohyphes nicholsae New Species are de
scribed from larvae taken in Ecuador. Leptohyphes liniti has a highly developed ridge
on the hind femora and otherwise is most similar to Leptohyphes tacajalo Mayo, also
from Ecuador. Leptohyphes nicholsae is closely related to L. curious Lugo-Ortiz and
McCafferty, described from Costa Rica, but differs in the presence of abdominal tuber
cles and color pattern.

Key Words: Ephemeroptera, Leptohyphidae, Leptohyphes liniti, Leptohyphes nichol
sae, New Species


RESUME

Leptohyphes liniti Nueva Especie y Leptohyphes nicholsae Nueva Especie son des
critas a trav6s de larvas colectadas en Ecuador. Leptohyphes liniti tiene una cresta
muy desarrollada en los f6mures posteriores, pero es muy similar a Leptohyphes taca
jalo Mayo, tambien de Ecuador. Leptohyphes nicholsae esta cercanamente relacio
nada a Leptohyphes curious Lugo-Ortiz & McCafferty, descrita de Costa Rica, pero
difiere en la presencia de proyecciones abdominales y en el color del abdomen.





Leptohyphes Eaton is a New World mayfly genus with 73 currently recognized spe
cies and has been treated by Eaton (1882, 1892), Navas (1920, 1931), Ulmer (1920),
Needham and Murphy (1924), Traver (1943, 1958), Allen (1967, 1973, 1978), Mayo
(1968), Brusca (1971),Allen and Roback (1969),Allen and Brusca (1973), Kilgore and
Allen (1973), Allen and Murvosh (1987), and Lugo-Ortiz and McCafferty (1995). Most
species of Leptohyphes are known from only larvae or only adults, and thus the tax
onomy of the genus will remain difficult until stage associations are established
(Lugo-Ortiz and McCafferty 1995). The various and sometimes unreliable characters
(e.g., apical spine on abdominal gill 2, which actually originates from underlying gill
filament of gill 2) used to describe species of Leptohyphes in the past suggest that the
status of several species requires further review.
Recently, one of us (RWS) collected mayflies from northern Ecuador, including two
distinctive new species of Leptohyphes. These species are named after M. L. Linit and
B. J. Nichols, who helped to collect the material upon which the descriptions herein
are based. Except where noted, the materials examined are deposited in the Wilbur R.
Enns Entomology Museum at the University of Missouri-Columbia, USA. All materi
als examined were collected by the three collectors indicated above.


March, 1998

















Wang, Sites & McCafferty: New Species of Leptohyphidae 69

Leptohyphes linitiWang, Sites and McCafferty, New Species
(Figs. 1-8)

Larva: Body length 4.5-6.0 mm; caudal filaments ca 3.0-4.0 mm. General color red
dish brown to light brown. Head patterned and setae as in Fig. 1. Body with scattered
minute spicules and without tubercles. Labrum dorsally with scattered, simple setae
and two to three rows of branched setae along the anterior margin (Fig. 2); mandible
with partially fused incisors (Figs. 3-4); hypopharynx with poorly developed superlin
guae, superlinguae with simple and branched setae (Fig. 5); maxillary palpi three
segmented (Fig. 6); labium with well-developed postmentum, labial palpi with long
setae, glossae reduced and with several branched setae (Fig. 7). Pronotum with lat
eral margins rounded and produced in anterior half (Fig. 1). Fore femora with well-de
veloped median transverse ridge with spines (Fig. 1); mid and hind femora with
elevated longitudinal ridge (highly developed in hind femora) extending from near
base to apex of femur, dorsal margins with prominent flat, long, blunt spurs (socketed)
and minute setae (Fig. 1); hind femora about 40% longer than fore femora, with ridge
width more than one-half length; hind tibiae with row of hairlike setae on ventral and
dorsal margins; hind tarsi about one-third length of hind tibiae; tarsal claws with sin
gle row of four to six denticles. Abdomen with scattered spicules; lateral flanges de
veloped on segments 2-7 (anterior margins of hind femora fitting on lateral flanges);
segments 6-9 with posterolateral projections; sterna reddish brown except hyaline
laterally on sterna 2-7. Abdominal gills 2 with basal spine (or projection) (Fig. 8). Cau
dal filaments with narrow dark brown bands near base in female (Fig. 1), and with
broad dark brown area near middle in male.
Adult: Unknown.
Holotype: Female larva, Ecuador, Carchi Prov, Rio San Juan, 1.8 km E Mal
donado, 2198 m, 16 July 1993. Paratypes: Nine larvae, same data as holotype; nine
larvae, Napo Prov, 6.2 km S Baeza (old town), 1865 m, 21 July 1993 (two housed in
the Purdue Entomological Research Collection, West Lafayette, Indiana; two housed
in the Museo Ecuatoriano de Ciencias Naturales, Quito, Ecuador; and two housed in
Universidad Cat6lica, Quito, Ecuador).
Other material examined: 14 larvae, same data as holotype; 20 larvae, Napo Prov,
6.2 km S Baeza (old town), 1865 m, 21 July 1993; three larvae, Pichincha Prov. Rio
Toachi nr footbridge, 0.3 km E Tinalandia, 741 m, 19 July 1993; one larva, Pichincha
Prov, tributary of Rio Toachi, 2.6 km S La Union del Toachi at dirt rd S from new
Quito Rd, 975 m, 19 July 1993; two larvae, Pichincha Prov., Rio Dos Rios at Dos Rios,
7.0 km NE on old Quito Rd, 1292 m, 19 July 1993; 42 larvae, Napo Prov, Rio Que
brada Juve, 1996 m, 20 July 1993.
Discussion: Leptohyphes liniti appears similar to Leptohyphes tacajalo Mayo from
Ecuador, but differs in the highly developed hind femora with marginal spurs and the
well-developed marginal rows of hairlike setae on the hind tibiae.
Larvae were taken in small to large streams with substrates consisting of stones,
stones in sand, and stones in vegetation. Elevations of the collection sites ranged from
741 to 2195 m and water temperatures ranged from 15-22 C.


Leptohyphes nicholsae Wang, Sites and McCafferty, New Species
(Figs. 916)

Larva: Body length 3.0 mm; caudal filaments ca 1.0 mm. Color pattern as in Fig.
9. Head pale brown, fringed with numerous long, fine, simple setae; ocelli raised
slightly on rudimentary tubercles; antennae pale yellow, nearly as long as head width.











Florida Entomologist 81(1)


/cc~,


,O1


Fig. 1. Leptohyphes linitiWang, Sites and McCafferty, New Species, larva, dorsal
view.


March, 1998

















Wang, Sites & McCafferty: New Species of Leptohyphidae 71


Figs. 2-8. Leptohyphes liniti Wang, Sites and McCafferty, New Species, larva. 2.
Labrum; 3. Left mandible; 4. Right mandible; 5. Hypopharynx; 6. Maxilla; 7. Labium;
8. Gill 2, ventral.

Labrum mostly with branched setae (Fig. 10); mandible with partially fused incisors
(Figs. 11-12); hypopharynx with well-developed superlinguae and marginal setae
(Fig. 13); maxillary palpi absent (Fig. 14); labium with regularly developed postmen
tum, labial palpi with sparse setae, glossae small and with apical branched setae (Fig.
15). Lateral margins of pronotum nearly parallel, fringed with fine, simple setae; fore
femora with well-developed, curved, setose transverse ridge in basal half of anterior
surface (Fig. 9); mid and hind legs with color pattern as shown in Fig. 9; mid and
hind femora and tibiae with long, fine, simple setae on ventral and dorsal margins;
hind femora subequal in length to fore femora; hind tibiae and hind tarsi subequal in
length; tarsal claws about half as long as tibiae, and with single row of four to six den










72 Florida Entomologist 81(1) March, 1998


'I


\~TT

N:


Fig. 9. Leptohyphes nicholsaeWang, Sites and McCafferty, New Species, larva, dor
sal view.


I) 'yl~


zl'


j
















Wang, Sites & McCafferty: New Species of Leptohyphidae 73


10


15 "- 16

Figs. 10-16. Leptohyphes nicholsae Wang, Sites and McCafferty, New Species,
larva. 10. Labrum; 11. Left mandible; 12. Right mandible; 13. Hypopharynx; 14. Max
illa; 15. Labium; 16. Gill 2, ventral.


tides. Abdominal terga 3-9 each with midposterior tubercle (strongly developed on
terga 6-9); abdominal segments 3-9 with well developed posterolateral projections,
and 3-8 with moderately developed lateral flanges (Fig. 9); sterna pale yellow. Oper
culate gills with underlying gill filament longer than operculate gill (Fig. 16), without
basal spine, pale yellow, ovate, weakly pointed distally, with distinct basal and me
dian blackish markings (Fig. 9). Caudal filaments without dark brown banded seg
ments, with whorls of short, simple setae at alternating articulations (Fig. 9).
Adult: Unknown.

















Florida Entomologist 81(1)


Holotype: Male larva, Ecuador, Pichincha Prov., Rio Peripa at Puerto Limon, 314
m, 18 July 1993. Paratype: Female larva, same data as holotype.

DISCUSSION

Leptohyphes nicholsae appears to be closely related to Leptohyphes curious Lugo
Ortiz and McCafferty from Costa Rica because both species possess the following at
tributes: small size, similar operculate gill shape, ridge and setal arrangements on
the legs, and the well-developed posterolateral projections on abdominal segments 7
and 8 (see Lugo-Ortiz and McCafferty 1995). It differs from L. curious by possessing
tergal tubercles and a different color pattern on the legs and operculate gills. Lugo
Ortiz and McCafferty (1995) noted the unique characteristics of L. curious and com
mented that it did not exactly fit the traditional definitions of either Tricorythodes Ul
mer or Leptohyphes. They further suggested that it was representative of a distinct
Neotropical lineage within Leptohyphes. The discovery of L. nicholsae shows indeed
that the lineage consists of more than one species.
The new species is known from only one collecting site. The Rio Peripa, where it
was taken, was at low elevation (314 m) at Puerto Limon. The collecting site was ap
proximately 30 m wide, had a stony substrate, and a water temperature of 24'C.

ACKNOWLEDGMENTS

We thank G. Onore, Universidad Cat6lica, Quito, for his assistance with local lo
gistics and in obtaining collecting permit No. 038-IC from the Ministerio de Agricul
tura y Ganaderia. We also thank A. Provonsha and C. Lugo-Ortiz, Purdue University,
West Lafayette, IN, for critically reading the manuscript. The Spanish abstract was
translated by C. Lugo-Ortiz. Partial funding for this project was provided in part by
MU project #PSSL0232. This is Missouri Agricultural Experiment Station journal se
ries paper No. 12632. The paper has also been assigned Purdue ARP Journal No.
15405.


REFERENCES CITED

ALLEN, R. K. 1967. New species of New World Leptohyphinae (Ephemeroptera: Tric
orythidae). Canadian Entomol. 99: 350-375.
ALLEN, R. K. 1973. New species of Leptohyphes Eaton (Ephemeroptera: Trico
rythidae). Pan-Pacific Entomol. 49: 363-372.
ALLEN, R. K. 1978. The nymphs of North and Central American Leptohyphes
(Ephemeroptera: Tricorythidae). Ann. Entomol. Soc. America 71: 537-558.
ALLEN, R. K., AND R. C. BRUSCA. 1973. New species of Leptohyphinae from Mexico
and Central America (Ephemeroptera: Tricorythidae). Canadian Entomol. 105:
83-95.
ALLEN, R. K., AND C. M. MURVOSH. 1987. Mayflies (Ephemeroptera: Tricorythidae) of
the southwestern United States and northern Mexico. Ann. Entomol. Soc.
America 80: 3540.
ALLEN, R. K., AND S. S. ROBACK. 1969. New species and records of New World Lepto
hyphinae (Ephemeroptera: Tricorythidae). J. Kansas Entomol. Soc. 42:372
379.
BRUSCA, R. C. 1971. A new species of Leptohyphes from Mexico (Ephemeroptera: Tri
corythidae). Pan-Pacific Entomol. 47: 146-148.
EATON, A. E. 1882. An announcement of new genera of the Ephemeridae. Entomol.
Mon. Mag. 18: 207-208.
EATON, A. E. 1892. Biologia Centrali-Americana, Insecta, Neuroptera, Ephemeridae.
Bernard Quaritch, London 38: 1-16.


March, 1998

















Wang, Sites & McCafferty: New Species of Leptohyphidae 75

KILGORE, J. I., AND R. K. ALLEN. 1973. Mayflies of the Southwest: new species descrip
tions, and records (Ephemeroptera). Ann. Entomol. Soc. America 66: 321-332.
LUGO-ORTIZ, C. R., AND W. P. MCCAFFERTY. 1995. Contribution to the taxonomy of
Leptohyphidae (Insecta: Ephemeroptera) of Central America. Stud. Neotrop.
Fauna Environ. 30: 165-176.
MAYO, V. K. 1968. Some new mayflies of the subfamily Leptohyphinae
(Ephemeroptera: Tricorythidae). Pan-Pacific Entomol. 44: 301-308.
NAVAS, L. 1920. Insectos Sudamericanos. la Serie. Anales Soc. Cient. Argentina 90:
52-72.
NAVAS, L. 1931. Insectos de la Argentina. Rev. Cos. Entomol. Argentina 3: 317-324.
NEEDHAM, J. G., AND H. E. MURPHY. 1924. Neotropical mayflies. Bull. Lloyd Libr., En
tomol. Ser. 4: 179.
TRAVER, J. R. 1943. New Venezuelan mayflies. Bol. Entomol. Venezolana 2: 7998.
TRAVER, J. R. 1958. Some Mexican and Costa Rican mayflies. Bull. Brooklyn Entomol.
Soc. 53: 8189.
ULMER, G. 1920. Neue Ephemeropteren. Arch. Naturg. 85: 180.


++++++++++++++++++++++++++++++++++++++++++++++++++++

















Baranowski & Slater: Cayman Island Lygaeidae


THE LYGAEIDAE OF THE CAYMAN ISLANDS WITH THE
DESCRIPTION OF A NEW SPECIES OF OCHRIMNUS
(HEMIPTERA)

RICHARD M. BARANOWSKI' AND JAMES A. SLATER2
1University of Florida Institute of Food and Agricultural Sciences
Tropical Research and Education Center, Homestead, FL 33031

Dept. of Ecology & Evolutionary Biology, University of Connecticut, Storrs, CT 06269

ABSTRACT

A key to the 50 species known from the Cayman Islands is provided, brief descrip
tions are given and the origin and relationships of the lygaeid fauna are discussed. A
new species is described and new synonymy is presented.

Key Words: Cayman Islands, Lygaeidae, new species

RESUME

Se introduce una clave para las 50 species que se conocen de las islas Caiman, se
presentan descripciones breves, y se discuten el origen y las relaciones de la fauna
Lygaeidae. Se describe una especie nueva y se introduce nueva sinonimia.





The insect fauna of the Cayman Islands has received considerable attention in re
cent years. Our own interest in these islands has been stimulated by this work since
we have for a number of years been concentrating a considerable part of our research
and field work on the lygaeid fauna of the West Indies. It thus seems appropriate to

















Florida Entomologist 81(1)


bring together our information on these interesting islands, discuss the faunal rela
tionships, and present a faunal list that is more in keeping with the actual species
composition than that currently reflected in the literature.
The natural history and biogeography of the Caymans have been treated in detail
by Brunt & Davies (1994) and will not be repeated here except to note that the islands
are all low lying and are closer geographically to such islands of the Greater Antilles
as Cuba and Jamaica than they are to any of the small island groups of the Caribbean.
One of the interesting aspects of the Cayman lygaeid fauna is that, in contrast to
the butterfly fauna (Askew 1994) in which endemism occurs only at the subspecific
level, at least 5 species are endemic. It must be admitted, however, that the Lygaeidae
have not been collected as intensively as the butterflies of the Caribbean. Thus some
of the apparent Cayman endemics may be the result of limited collecting on other is
lands. Nevertheless, the Cuban lygaeid fauna have been more carefully studied in the
past than has that of any of the other islands, and we have collected extensively on Ja
maica without taking any of these endemic species.
Our prior knowledge of the Cayman fauna comes from the 1938 Oxford University
Expedition material that was studied by Scudder (1958). He reported 17 species
present of which four were described as new. Askew (1994) noted that thirteen species
were collected on Grand Cayman, eight on Cayman Brac, and three on Little Cayman.
Slater (1964) listed the same species. Froeschner (1983) listed two species from Grand
Cayman Island, one of which represented an additional species. Based on our collect
ing over the past 10 years, we can list a total of 50 species, a number surprisingly close
to the known butterfly fauna. With this number of species we feel confident that we
have a reasonably complete inventory of the fauna of the Caymans.
From the outset we have been interested in the possible vicariant nature of the
fauna relative to overwater dispersal. We feel that it is not yet possible to analyze sta
tistically the number of species relative to island size, particularly because Little Cay
man seems relatively poorly collected. Nor can we make meaningful contributions to
the degree of faunal "turnover" due to arrival of new immigrants and extinction of el
ements of the known fauna. We do believe that our present knowledge of the lygaeid
fauna provides a base line from which future studies can be profitably pursued. All
species described as endemic by Scudder (1958), with the exception of Ozophora mi
nuscula Scudder, have been taken on the Cayman Islands and none have been taken
on any other island of the Caribbean. We also recognize one additional new species as
endemic so that at least 5 species are considered endemic, or 10% of the fauna. Askew
(1994) commented upon the dominance of Lygaeidae in the Hemiptera fauna, at least
on Grand Cayman, and while he noted that this figure represented only a small frac
tion of the fauna, he believed that the figures probably accurate reflected the balance
of family representatives. We see no reason to doubt the validity of this conclusion.
Of the species that are not endemic on the Caymans, the great majority are wide
spread in the West Indies. Many of these are "weed species" that live in disturbed hab
itats and frequently reproduce on a number of host plants, or that live on or below
host plants that thrive in ruderal environments.
Dieuches armatipes (Walker) and Oxycarenus hyalinipennis Costa are Old World
species that have only recently been reported from the Western Hemisphere.
Excluding these recently introduced species what can we conclude about the origin
and relationships of the Caymans lygaeid fauna? To attempt to answer this question,
we compared the fauna of the Caymans with that of Cuba and Jamaica, the two large
islands most likely to have served as source areas. Askew (1994) found that the but
terfly fauna of the Caymans was derived predominantly from Cuba. He found that 42
of the 48 butterfly taxa were also in Cuba but only 29 were shared with Jamaica and
progressively fewer with Hispaniola, Puerto Rico, and the Bahamas.


March, 1998

















Baranowski & Slater: Cayman Island Lygaeidae


The lygaeid fauna, while not contradicting this relationship, does not support it to
any extent. Of the total of 50 lygaeid species now known from the Caymans, 39 also
occur on Cuba, but 34 occur on Jamaica. Even this difference appears more likely to
represent lack of collecting than actual absence of species on one or the other of the
islands. For example, Nysius raphanus Howard and Cymodema breviceps Stal have
been reported from Cuba but not Jamaica, but both are widespread almost through
out the Caribbean. Conversely, Oedancala cladiumicola Baranowski and Slater is a
relatively recently recognized species that is known from southern Florida as well as
the Bahamas, Caicos, and Jamaica. It is host specific and is almost certain to be found
on Cuba.
We conclude that most, if not all, of the Caymans fauna has reached the islands by
overwater dispersal rather than as a result of vicariance. Slater's (1988) paper detail
ing his disagreement with Rosen's (1985) depreciation of dispersalist concepts, should
be consulted to understand our position on this matter.
Although we believe the present evidence strongly supports the probability of
overwater dispersal as the primary reason for the present Caymans lygaeid fauna (in
agreement with Askew's (1994) conclusions on the butterfly fauna), we feel that while
Cuba may well be the source area from which much of the fauna is derived, the ma
jority of species are so widespread in the Caribbean that it is impossible to demon
state this.
In support of our hypothesis that the origin of the Cayman fauna is primarily the
result of overwater dispersal, several points should be considered. Most important is to
consider what is not there, as Rosen (1985) and some other biogeographers seem reluc
tant to do. None of the higher taxa that have restricted distributions in the Greater An
tilles are present. Particularly striking is the absence of the Pamphantinae. Slater
(1988) indicated that the distribution on the islands suggests vicariance between Cuba
and Hispaniola (and possibly Puerto Rico) since a number of sister taxa occur on the
two islands and the subfamily is not otherwise represented in the West Indies, include
ing its absence from Jamaica. This still seems essentially true for the islands, although
extensive collecting in South America has revealed a considerable pamphantine fauna.
Concepts of the taxon as an island-mainland vicariance example, however, will require
cladistic reexamination once the mainland fauna is better understood.
None of the endemic antillocorine West Indian genera, such as Bathydema and An
tillodema, are present on the Caymans, nor are representatives of the geocorine Nin-
yas that occurs in less disturbed habitats in both Jamaica and Cuba.
Several widespread Caribbean species are absent, indicating a rather random dis
persal pattern. Examples are .. .'.. J ..'. compact Distant and Oedancala bimacu
lata (Distant), both of which are sedge feeders and might be expected on the islands. The
absence of Ozophora rubrolinea, an abundant species on the north coast of Jamaica, and
common on the mainland of Central and northern South America is unexpected. Its ab
sence appears to be real, for members of the genus come to lights abundantly, and a
number of widespread species of Ozophora are common on the Caymans.
Thus we see a general pattern of a fauna composed primarily of species very wide
spread on the islands. This distribution suggests the importance of overwater coloni
zation in producing this pattern, even relative to the two species apparently recently
introduced from the Eastern Hemisphere. Superimposed on this basic pattern is the
presence of several endemic species and the absence of some widespread and common
species, as well as the absence of taxa that tend to be restricted to islands of the
Greater Antilles.
All measurements are given in millimeters. The following abbreviations are used;
RMB -Richard M. Baranowski collection, JAS -James A. Slater collection, USNM
United States National Museum, BMNH -British Museum of Natural History. Orig

















Florida Entomologist 81(1)


inal references are not given as they can be found in Slater (1964) or Slater and
O'Donnell (1996). We are aware of the higher classification proposed by Henry (1997),
but prefer to retain the traditional classification for a faunal paper of this type.


KEY TO THE CAYMAN ISLANDS SPECIES OF LYGAEIDAE

1. Suture between abdominal sterna 4 and 5 curving forward laterally and not at
training lateral margin of abdomen (Rhyparochrominae) ................. 2
1'. Suture between abdominal sterna 4 and 5 straight or nearly so and attaining
lateral m argin of abdom en ........................................ 32
2. With at least spiracles of abdominal segments 3 and 4 located dorsally .... 3
2'. All abdominal spiracles located ventrally ............................. 4
3. Lateral margins of anterior pronotal lobe carinate or explanate; only spiracle of
abdominal segments 3 and 4 located dorsally (Rhyparochromini) ...........
................................. .. D ieuches arm atipes
3' Lateral margins of anterior pronotal lobe rounded; abdominal spiracles on seg
ments 2, 3, and 4 located dorsally (Myodochini) ................... .... 16
4. Apical corial margins deeply concave on inner half (Antillocorini) ......... 5
4'. Apical corial margin straight or nearly so ............................ 6
5. Posterior pronotal lobe uniformly brown ................ Botocudo species
5'. Posterior pronotal lobe brown with pale markings ...... Cligenes distinctus
6. Trichobothria on abdominal sterna 4-5 arranged in a longitudinal linear row
with posterior trichobothrium located caudad of spiracle 5; head dorsally with
an iridescent area at base; usually with a trichobothrium present at each an
tero-lateral pronotal area (Lethaeini) ............. Paragonatas divergens
6'. Two posterior trichobothria on segments 4 and 5 located dorso-ventrad of one
another; head above lacking iridescent areas; never with antero-lateral prono
tal trichobothria (Ozophorini) ...................... .............. 7
7. Forewings coleopteroid, meeting along midline; membrane absent or greatly
reduced ...................................... Ozophora coleoptrata
7'. Forewings macropterous, fully developed ............................. 8
8. Dorsal surface of body with short, but distinct upstanding hairs (viewed later
a lly ) . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
8'. Dorsal surface glabrous or with scattered decumbent hairs, or at most an iso
lated upstanding hair ............. ........... ................. 10
9. Small species, 5 mm or less in length ............... Ozophora coleoptrata
9'. Larger species, more than 5 mm in length ........... Ozophora burmeisteri
10. Bucculae U-shaped; head anteriorly declivent, almost at a right angle to body
length ........................................ Ozophora laticephala
10'. Bucculae V shaped; head somewhat declivent, but never downward curved at
alm ost a right angle to body length ................................. 11
11. Small species, less than 4.75 mm in length .......... Ozophora minuscule
11'. Larger species, well over 5 mm in length ............................ 12
12. Femora dark brown .................. Ozophora pallidifemur fuscifemur
12'. Femora stramineous, with or without a brown annulus, never completely dark
b row n . . . . . . . . . . . . . . . . . . . . . . .. 13
13. Humeral pronotal angles weakly, but distinctly notched ..................
.................................. Ozophora pallidifemur pallidifemur
13'. Humeral pronotal angles evenly rounded ............................ 14
14. Membrane completely dark, lacking a conspicuous white apical macula or
stripe .......................................... Ozophora umbrosa


March, 1998

















Baranowski & Slater: Cayman Island Lygaeidae


14'. Apex of membrane with a conspicuous pale macula or stripe ............ 15
15. Hemelytra anterior to transverse dark fascia variegated with brown and yellow
areas (sometimes colors obscured in very pale faded specimens) ...........
........................ ......... Ozophora quinquemaculata
15'. Hemelytra anterior to transverse dark fascia either completely pale and
strongly contrasting or at most with oblique dark dash on corium laterally at
level of distal 12 of scutellum ........................... Ozophora carol
16. Interocular distance less than postocular distance .... Myodocha unispinosa
16'. Interocular distance greater than postocular distance ................. 17
17. A crescent-shaped striated area present ventro-laterally on anterior portion of
abdom inal sternum ................................... ....... 18
17'. Striated area lacking on anterior portion of abdominal sternum ......... 19
18. Pronotum markedly bilobed with transverse impression deeply incised; forefe
mur with spines present on both inner and outer edges of ventral surface ...
Froeschneria piligera
18'. Pronotum with transverse impression not deeply incised; forefemur with
spines present only along inner edge of ventral surface ..................
............................................... Ligyrocoris litigiosus
19. Evaporative area covering a considerable portion of metapleuron; more than 3
rows of claval punctures; 3rd antennal segment usually longer than interocular
distance ..................................... ................. 22
19'. Evaporative area around metathoracic scent gland auricle reduced to a narrow
band around auricle; claval punctures usually in 3 rows; length of 3rd antenna
segment usually less than interocular distance (Prytanes) .............. 20
20. First antennal segment with distal end dark ............. Prytanes confusa
20'. First antennal segment unicolorous throughout ................... .. 21
21. Forefemora light yellow .............................. Prytanes minima
21'. Forefemora chiefly dark brown ................... ... Prytanes dissimilis
22. Mesoacetabulum with mesepimeron emergent from between meso and me
tepistern um .................................................. 23
22'. Mesepimeron enclosed by metepisternum touching mesepisternum ...... 29
23. Head relatively elongate with a distinct "neck" present; postocular distance
equal to or greater than distance between ocelli (Heraeus) ............. 24
23'. Head less elongate, lacking a distinct "neck"; postocular distance less than dis
tance between ocelli (Neopamera) ....................... .......... 25
24. Smaller species (less than 6 mm), apical area of corium and apex of membrane
without white areas ............................... Heraeuspulchellus
24'. Larger species (7-8 mm), apical area of corium with large irregular white mac
ula; apex of membrane with median white area ........ Heraeus triguttatus
25. Fourth antennal segment with a conspicuous white or light yellow subbasal an
nulus ...................................... ......... .......... 26
25'. Fourth antennal segment unicolorous throughout .................... 27
26. Relatively large species (7-10 mm) with eyes strongly produced ...........
.Neopamera neotropicalis
26'. Relatively small species (less than 6 mm), eyes not large, not prominently pro
duced ........................................ Neopam era albocincta
27. Anterior pronotal lobe impunctate, corium with a distinct dark transverse fas
cia ............................................ Neopamera bilobata
27'. Anterior pronotal lobe punctate, corium nearly uniformly testaceous, lacking a
transverse dark fascia ........................................... 28
28. Third antennal segment only two-thirds length of segment two; smaller species
(not over 4.5 mm) .............................. Neopamera intermedia

















Florida Entomologist 81(1)


28'. Third antenna segment much more than two thirds length of segment two;
larger species (5 mm) ............................. Neopamera vicarius
29. Elongate (6-9 mm in length); anterior pronotal lobe flattened, slightly convex,
in lateral view lower than posterior lobe; pronotal collar with a median "dip" to
posterior margin (Paromius) ..................... ................ 30
29'. Small (not over 5-6 mm); anterior pronotal lobe strongly convex, not lower than
posterior lobe in lateral view; pronotal collar essentially straight across midline
(Pseudopachybrachius) ..................... .................... 31
30. Length of anterior pronotal lobe at least 1.8 times length of posterior pronotal
lobe; anterior pronotal lobe usually reddish brown ....... Paromius dohrnii
30'. Length of anterior pronotal lobe less than 1.6 times length of posterior pronotal
lobe; anterior pronotal lobe usually black .............. Paromius longulus
31. Posterior (apical) margin of corium black, posterior femora pale ...........
............................ .. Pseudopachybrachius vinctus
31'. Posterior margin of corium pale or light brown; posterior femora with dark
markings . ........................ Pseudopachybrachius basalis
32. Abdominal spiracles on segments 2 through 7 all placed dorsally ........ 33
32'. At least one pair of spiracles on segments 2 through 7 located ventrally ... 44
33. Clavus punctate; posterior pronotal margin not depressed laterad of base of
scutellum ...................... ............... Kleidocerys virescens
33'. Clavus impunctate; posterior pronotal margin depressed laterad of base of
scu tellu m . . . . . . . . . . . . . . . . . . . . . . . . . . .. 3 4
34. General coloration dull yellowish brown, never with bright red or orange mark
ings, apical corial margin sinuate on mesal half; hind wing lacking a subcosta
and possessing intervanals (Orsillinae) ............................. 35
34'. Generally with red or orange coloration; apical corial margin straight, hind
wing possessing a subcosta and lacking intervanals (Lygaeinae) ......... 40
35. Costal margin of corium straight for greater part of length, at least to level of
distal end of claval commissure; connexivum often exposed laterad of corium.
................. ................. Neortholomusjamaicensis
35'. Costal margin of corium expanded from base, never straight for distance be
yond level of posterior end of scutellum; connexivum not exposed laterad of co
riu m .......................... ........ ..... .............. 36
36. Stridulatory structure consisting of a row of fine grooves and ridges present on
lateral corial margin (Xyonysius) .................................. 37
36'. Lateral margins of corium lacking a stridulatory structure (Nysius) ...... 38
37. Corium not or scarcely constricted at base; pronotum distinctly longitudinally
calloused on each side of midline; veins of corium unspotted or at most very
faintly spotted .................. .................. Xyonysius basalis
37'. Corium conspicuously constricted at base; pronotum not distinctly longitudi
nally calloused on either side of midline; veins of corium more or less heavily
spotted with fuscous ............................ Xyonysius californicus
38. Bucculae low, gradually tapering posteriorly, fading out gradually near base of
head ............................................. N ysius raphanus
38'. Bucculae high anteriorly, slightly narrowing posteriorly, ending abruptly at or
near base of head .................................... ........ 39
39. Basal portion of lateral corial margins with prominent hairs ..............
................... .............................. N ysius scutellatus
39'. Basal portion of lateral corial margins devoid of hairs, or at most with minute,
extremely small hairs present .......................... Nysius tenellus


March, 1998

















Baranowski & Slater: Cayman Island Lygaeidae


40. Scutellum tumid and swollen with a weak median longitudinal carina, but
never with lateral areas excavated; lacking a subbasal transverse carina (On-
cop eltus) .................. ......... .......... ................ 41
40'. Scutellum not tumid and swollen with a median carina and adjacent areas flat
or excavated; a subbasal transverse carina usually present ............. 42
41. Hemelytral membrane with a white mark just basad of center ............
.............................................. Oncopeltus aulicus
41'. Hemelytral membrane without white markings ....... Oncopeltus fasciatus
42. Pronotum with 4 short deep transverse impressions present behind calli
(Ochrim nus) ................... ............ ........ .......... 43
42'. Pronotum often punctate behind calli, but without 4 transverse impressions
.Ochrostomus pulchellus
43. Dorsum black except for indistinct ocher pronotal and corial margins ......
.................................. .. Ochrim nus nigriceps
43'. Dorsum black except posterior pronotal lobe largely orange ..............
.............................. .. Ochrim nus bracensis n. sp.
44. Abdominal spiracles on segments 2 to 5 located dorsally, spiracles of segment 7
located ventrally ...................... ............... ........ 45
44'. Abdominal spiracles on at least segments 6 and 7 located dorsally, or all spira
cles ventral ...................................... .... ........ 48
45. Hemelytra coarsely punctate (Cyminae) ............................ 46
45'. Hemelytra impunctate, or at most with a few scattered punctures (Blissinae)
47
46. Head strongly deflexed in front; eyes somewhat stalked and produced away
from antero-lateral margins of pronotum; corium chiefly hyaline with only a
few mesally located punctures ................... .. Cymoninus notabilis
46'. Head not strongly declivent anteriorly; eyes usually in contact with or nearly in
contact with antero-lateral pronotal angles; corium not hyaline, densely punc
tate over almost entire surface ..................... Cymodema breviceps
47. Body relatively short (less than 4 mm); black with white markings; forecoxal
cavities open posteriorly .............................. Blissus antillus
47'. Body elongate and slender; gray brown; forecoxal cavities closed posteriorly .
................................ .. Ischnodem us praecultus
48. Abdominal spiracles on segments 3 and 4 located dorsally; eyes protruding and
reniform; forefemora not greatly incrassate and not armed below with number
ous spines (Geocorinae) ............................. .......... 49
48'. All abdominal spiracles located ventrally; eyes not unusually large and reni
form; forefemora incrassate and armed below with numerous spines ..... 50
49. Head and pronotum yellow-brown; vertex smooth and shining ............
Geocoris punctipes
49'. Head and pronotum black, at least pronotum with a strongly contrasting white
stripe running longitudinally through meson ......... Geocoris lividipennis
50. Forefemora only moderately swollen; corium expanded, extending beyond lat
eral margins of abdomen; bucculae extending to base of head; hind coxae
widely separated (Oxycareninae) .............. Oxycarenus hyalinipennis
50'. Forefemora strongly swollen; corium not extending beyond lateral margins of
abdomen; bucculae short, confined to front of head; hind coxae not widely sep
arated (Pachygronthinae) ........................................ 51
51. Apical corial margin with a distinct dark spot (may be faint) along margin ..
................................ .. Oedancala crassim ana
51'. Apical corial margin lacking a distinct dark spot . Oedancala cladiumicola

















Florida Entomologist 81(1)


LYGAEINAE
Ochrimnus bracensis Baranowski & Slater, NEW SPECIES

Black, posterior portion of pronotum orange, fourth antennal segment, labium and
tarsi brown. Line between black and orange portions of pronotum forming a "W."
Head, black areas of pronotum, scutellum, clavus, corium, pleural areas of thorax,
and abdominal segments 2-5 densely clothed with decumbent black hairs tipped with
gold. Hairs on orange part of pronotum light with gold tips. Lateral margin of mem
brane narrowly white. Abdominal segment 6 and sternal areas of segments 2-5 and
legs with long golden hairs.
Length head 1.0, width 1.20, interocular space 0.75. Pronotum trapezoidal, ante
rior margin concave, lateral margins straight, posterior margin slightly convex.
Length pronotum 1.33, width 2.08. Scutellum with prominent median carina stem
and arms. Length scutellum 0.88, width 1.15. Length claval commissure 0.65. Midline
distance apex clavus to apex corium 2.10. Midline distance apex corium to apex mem
brane 2.65. Labium short, extending posteriorly between meso and metacoxae.
Length labial segments I 0.62, II 0.65, III 0.68, IV 0.58. Antennal segments I-III
densely clothed with short, decumbent black, gold tipped hairs sparsely interspersed
with long upright dark hairs. Segment IV densely clothed with short decumbent gold
hairs and long upright gold hairs. Length antennal segments I 0.44, II 1.02, III 0.90,
IV 1.06. Total body length 5.50.
Types. Holotype. 6 CAYMAN BRAC: The Creek, 17-X-1995, H. V & R. M. Bara
nowski blacklightt trap). In United States National Museum (USNM). Paratypes. 4d,
4 same data as holotype; 1d, 2 same except 20-X-95; 19, same except 6-9-VII-97;
2d, 39 same except 7XI-95, E. A. Dilbert; 29, same except 8-XI-95; 19, same except
26-V96; 1 same except 28-V96; 19 13-VI-96; 29, same except 26-VI-96; 19,same
except 22-VII-96. In R. M. Baranowski, J. A. Slater, United States National Museum,
Florida State Collection of Arthropods, American Museum of Natural History collec
tions.
Etymology: Named for the island, Cayman Brac, on which it appears to be en
demic.
This striking species very similar to 0. nigriceps, is readily distinguished by the
unique black coloration with only the posterior pronotal lobe a strongly contrasting
orange and by the uniquely colored hairs.


Ochrimnus nigriceps Scudder

Moderate sized (5.8-6.8), almost completely black-brown, covered with a dense, de
cumbent dark pubescence. Apical four-fifths of fourth antennal segment and margin
of membrane very narrowly pale.
Grand Cayman (Scudder 1958, RMBJAS).


Ochrostomus pulchellus (Fabricius)

Head dark brown with pale basal spot. Pronotal calli and 2 broad rays on posterior
pronotal lobe dark brown. Area anterior to calli white, lateral areas red. Inner one
half of clavus white, outer one-half dark brown. Corium dark brown with lateral and
apical margins broadly white, banded with red stripe just within pale margin. Mem
brane black with white margin.
Grand Cayman (Scudder 1958, Froeschner 1983, RMB), Cayman Brac (RMB), Lit
tle Cayman (RMB).


March, 1998

















Baranowski & Slater: Cayman Island Lygaeidae


Oncopeltus aulicus (Fabricius)

Red and black, easily recognizable by the large black macula covering most of pos
terior pronotal lobe. Usually a conspicuous white bar on forewing membrane.
Grand Cayman (RMB).

Oncopeltus fasciatus Dallas

One of the larger members of the genus (10-12). Orange-red and black. Central
area of pronotum with a transverse fascia, most of membrane and appendages black.
Grand Cayman (Froeschner 1983, RMB, NMNH).

ORSILLINAE
Neortholomusjamaicensis (Dallas)

Small (4-5), narrow, elongate. Dull yellowish gray with numerous brown spots on
head, pronotum, and hemelytra. Scutellum dark anteriorly with a broad pale Y
shaped callosity.
Grand Cayman (RMB).

Nysius raphanus Howard

Very small (3-4), yellowish brown. Scutellum black, except at extreme distal end.
Pronotum short, nearly twice as wide as long. Bucculae very low and tapered to pos
terior end.
Grand Cayman (RMB).

Nysius scutellatus Dallas

Small (3-3.5), bucculae high anteriorly, ending abruptly at or near base of head.
Basal portion of corial margins with prominent hairs.
Grand Cayman (Scudder 1958), Cayman Brac (RMB).

Nysius tenellus Barber

Small (3.6-4), pale yellowish testaceous, bucculae strongly elevated throughout.
Pronotum only one-third wider than long. Corial veins usually unspotted. Scutellum
bicolored or black.
Grand Cayman (RMB).

Xyonysius basalis (Dallas)

Subequal in size to X. californicus and paler in color, yellowish testaceous rather
than cinereus. Lateral corial margin scarcely contracted basally, entire lateral corial
margin slightly convex rather than straight. Male genital capsule either completely
pale yellow or slightly fuscous basally
Cayman Brac (Scudder 1958).


Xyonysius californicus (Stal)

Moderate sized (4.7-7), dull yellowish to brownish gray. Bucculae very short,
scarcely extending midway to base of head, head and pronotum subequal in length.
Male genital capsule black with broad pale yellow margin.

















Florida Entomologist 81(1)


Grand Cayman (RMB), Cayman Brac (RMB), Little Cayman (RMB).


ISCHNORHYNCHINAE
Kleidocerys virescens (Fabricius)

Relatively small (3-3.5), with head, pronotum, and scutellum ochraceous with fus
cous punctures. Scutellum usually dark anteriorly with distal end pale.
Grand Cayman (RMB).


CYMINAE
Cymoninus notabilis (Distant)

Small (3-3.3), elongate, slender. Head, pronotum, and scutellum somewhat pubes
cent, dark reddish brown. Corium yellowish with extreme apex darkened. Legs dull
yellow. Abdomen usually brownish or yellowish, sometimes, particularly in females,
green. Apex of labium and distal tarsal segment fuscous. Second antennal segment
1.5 times length of segment 3.
Grand Cayman (RMB), Cayman Brac (RMB), Little Cayman (RMB).


Cymodema breviceps (Stil)

Moderate sized (3.4-3.7), light yellow-brown with first 3 antennal segments concol
orous, head and 4th antennal segment darker. Pronotum with yellow line mesally on
anterior half. Scutellum also with median yellow line. Apical margin of corium darker.
Grand Cayman (RMB).


BLISSINAE
Blissus antillus Leonard

Blissus plans Leonard 1968: 151-152. NEW SYNONYMY
Blissus slater Leonard 1968: 150-151. NEW SYNONYMY.
Moderately small (2.5-3.5), posterior pronotal lobe black, strongly contrasting with
gray anterior lobe. Labium frequently extending posteriorly beyond middle of mesos
ternum. Hemelytra white with black-brown markings; membrane white. Both mac
ropterous and brachypterous forms known.
Grand Cayman (RMB), Cayman Brac (RMB), Little Cayman (RMB).
Leonard (1968) described three species of Blissus from the Caribbean:B. slater and
B. antillus from Puerto Rico, and B. plans from Grenada. His descriptions are based
largely on color, pruinosity, size, and the shape of the metathoracic scent gland peri
treme. In some instances he described a feature for one species, but did not discuss or
compare the condition of the same feature in the other species. For example, he stated
that the scutellum of B. slateri is distinctly punctate, but did not indicate the condition
of the punctation in the other two species. In fact, the scutellum is punctate in all three
species. We have examined considerable material from Jamaica, Dominican Republic,
Trinidad, St. Barthelemy, Dominica, Tortola, Virgin Gorda, and St. Lucia and find the
scutellum punctate in all specimens examined. Leonard stated B. slateri possesses
light straw-yellow setae on the pronotum but that B. antillus has silvery setae on the
pronotum. We cannot see these differences even in the paratypes examined. Because
the scent gland peritreme varies in the island populations we examined, we believe
that it is not a reliable differentiating character. We dissected male genital capsules
and parameres of several paratypes, representing all three species, as well as from


March, 1998

















Baranowski & Slater: Cayman Island Lygaeidae


specimens from other islands and do not find significant differences. In our opinion
Blissus is represented by a single species in the West Indies. We elect to use the name
antillus for this species and reduce B. slater and B. plans to synonymy.
In addition to our inability to find differentiating features, the West Indian popu
nations occur exclusively in ruderal habitats, suggesting that this is another example
of a "weed" species found in disturbed habitats throughout the Caribbean.
The relationship of B. antillus to the ubiquitous Florida chinch bug, B. insularis
Barber, is important. We have not found differences in the genital capsule or in the
parameres between West Indian specimens and specimens from Florida. However,
this is the case with a number of apparently distinct species of Blissus.
B. insularis can be separated from B. antillus by a combination of characters. B. in-
sularis always has uniformly straw-colored legs whereas B. antillus varies from hav
ing dark brown legs to light brown with a dark brown annulus on one or more femora.
The most constant differentiating feature is the anterior portion of the pronotum,
which in B. insularis, is covered by a uniform, undivided pubescent band that reached
the anterior margin. The pubescent band of B. antillus does not reach the anterior
margin and is completely, or partially, divided along the midline.
B. insularis does occur in the West Indies, as we have examined specimens from
the Bahamas.

Ischnodemus praecultus Distant

Ischnodemus slater Alayo & Grillo 1982: 58-62 NEW SYNONYMY.
Moderate sized (5-5.5). Hemelytra smoky colored with pale white to dull testa
ceous membrane. Surface of head, pronotum, and scutellum predominantly or en
tirely dull grayish or reddish brown pruinose. Lateral corial margins grayish brown
with shining areas of posterior portion of pronotum separated into three distinct mac
ulae.
Grand Cayman (RMB).
We have examined the holotype of slaterifrom Cuba and believe it to be conspe
cific with the widespread and somewhat variable I. praecultus.

GEOCORINAE
Geocoris lividipennis Stal

Small (2.5-3), strikingly colored, with head, pronotum, and scutellum chiefly black
contrasting with the pale yellow wings. Pronotum with a complete median longitudi
nal pale stripe and lateral areas of pronotum often yellow-brown. Vertex granulose.
Grand Cayman (RMB), Cayman Brac (RMB), Little Cayman (RMB).


Geocoris punctipes (Say)

A moderate sized (3-3.5) big-eyed bug; pale straw-yellow, usually with a dark me
dian scutellar stripe. Vertex of head smooth and polished with a median sulcus ex
tending to base of head.
Grand Cayman (RMB).


OXYCARENINAE
Oxycarenus hyalinipennis Costa

Small (3-4), elongate, pronotum and head tapering anteriorly. Head and pronotum
uniformly brown with dense, upright hairs, entire hemelytra hyaline. Abdomen and

















Florida Entomologist 81(1)


femora shining dark brown, meso and metatibiae with a striking median, broad,
white annulus.
This insect, known as the cotton seed bug, is a common and widespread species in
the Old World tropics. It is an introduced species in the Western Hemisphere and has
been established for many years in South America.
Slater & Baranowski (1994) reported it for the first time from the West Indies from
Long Island, Bahamas.

PACHYGRONTHINAE
Oedancala crassimana (Fabricius)

A relatively robust yellowish brown species with relatively thick antennal seg
ments. Usually less than 7.5 mm in length. Often with a dark spot present midway
along apical corial margin. This is often absent in West Indian specimens, in which
case it can be distinguished from 0. acuminata by the shorter labium; from O. cla
diumicola by the lack of reddish coloration and from 0. cubana by the more robust
nonlinear body and by not having the scutellum black adjacent to the pale median
vitta.
Grand Cayman (Scudder 1958, RMB).

Oedancala cladiumicola Baranowski & Slater

Similar to crassimana, but lacking black spot along apical corial margins. Reddish.
Found only on sawgrass.
Grand Cayman (RMB).

RHYPAROCHROMINAE


ANTILLOCORINI
Cligenes distinctus Distant

Small (2.5-3.0), robust with generally dark appearance. Head blackish, anterior
pronotal lobe, scutellum, and ventral surface dark brown, strongly contrasting with
testaceous hemelytra and legs. Corium with two spots along lateral margins, one at
apex of corium, one midway between base and apex. Entire pronotal surface densely
punctate with a very coarse row anteriorly, giving impression of a weak pronotal col
lar.
Grand Cayman (RMB), Cayman Brac (RMB).

Botocudo species

We have collected an apparently undescribed species of the Botocudo complex on
Cayman Brac. The relationships of species currently placed in Botocudo are very un
satisfactory. Therefore, we feel it best to wait until the generic limits of this tribe are
studied and redefined before attempting to place this species.

LETHAEINI
Paragonatas divergens (Distant)

Moderate sized (4-5); dark brown with humeral angles of pronotum, an elongate
vitta on clavus, and irregular spots on corium yellow. Dorsal surface with sparse up
right hairs. Femora dark brown with distal tips pale; tibiae and tarsi light brown.


March, 1998

















Baranowski & Slater: Cayman Island Lygaeidae


Grand Cayman (Scudder, 1958, RMB), Cayman Brac (Scudder 1958, RMB).

MYODOCHINI
Heraeus pulchellus Barber

One of the smallest West Indian Heraeus species, barely exceeding 4 mm in length;
testaceous, lacking an annulus on fourth antennal segment; possesses complete dark
brown fascia across hemelytra.
Grand Cayman (RMB), Cayman Brac (RMB).

Heraeus triguttatus (Guerin)

Larger (7-8) than pulchellus. Typically bright reddish brown with apex of corium
and most of membrane black. Apical area of corium possessing a large irregular white
macula. Apex of membrane with conspicuous subquadrate median white area.
We have specimens from Grand Cayman and Cayman Brac that are dark brown
rather than bright reddish brown; however, we can find no morphological differences
other than the color.
Grand Cayman (Scudder 1958, RMB), Cayman Brac (RMB).

Neopamera albocincta (Barber)

Elongate (5-5.5), pale reddish to reddish brown, postmedian corial fascia generally
broken into series of spots. Fourth antenna segment with proximal white annulus.
Elongate head relatively more attenuated than N bilobata.
Grand Cayman (RMB), Cayman Brac (Scudder 1958, RMB).

Neopamera intermedia (Barber)

Moderate sized (4-4.5), brownish with pale markings; legs yellowish with a narrow
band near distal end of posterior femora; antennae light brown with distal third of
segment III and all of segment IV darker.
Grand Cayman (RMB), Cayman Brac (Scudder 1958, RMB).


Neopamera bilobata (Say)

Rhyparochromus scutellatus Dallas 1852: 575-576 NEW SYNONYMY
Resembles N. albocincta closely in form and color, but tends to run somewhat
darker (although the color is variable), and is slightly larger and more robust and
lacks a pale proximal area on the 4th antenna segment.
Dallas' species N scutellatus has been treated as a subspecies of N bilobata since
its status was reduced by Van Duzee (1909). Barber (1953) discussed the status, not
ing the darker femora, relatively shorter anterior pronotal lobe, and shorter second
antenna segment. However, such specimens apparently have no geographic signifi
chance and occur in many populations. There seems no reason to treat this as a tri
nomen in the modern concept of the subspecies, and it is here synonymized.
Grand Cayman (Scudder 1958), Cayman Brac (RMB).


Paromius longulus (Dallas)

Elongate, moderate sized (5.5-7), head, anterior pronotal lobe, scutellum and un
der surface frequently dull black, often thickly clothed with grayish pubescence. Pos

















Florida Entomologist 81(1)


terior pronotal lobe reddish brown with darker punctures. Corium and clavus dull
testaceous. Antennae reddish brown with distal end of third and usually all of fourth
segment fuscous.
Grand Cayman (RMB).

Paromius dohrnii Guerin

Light tan, elongate, with anterior pronotal lobe reddish brown and almost twice
the length of posterior lobe, with transverse impression shallow and usually obsolete
mesally
Grand Cayman (RMB).

Pseudopachybrachius basalis (Dallas)

Small (3.5-5), robust; lateral corium lacking a distinct postmedian transverse fas
cia, margins completely pale. Oval pale spot present near inner apical corial angle.
Head, pronotum, and scutellum dull black, corium dull yellow with dark brown punc
tures. Antennae reddish brown.
Grand Cayman (RMB), Cayman Brac (RMB).

Pseudopachybrachius vinctus (Say)

Small (2.8-3.0), head dark, pronotum contrasting with pale hemelytra having a
conspicuous black spot on apical corial margin. Fourth antennal segment dark brown,
contrasting with 3 pale proximal segments. Legs pale.
Grand Cayman (Scudder 1958, RMB), Cayman Brac (Scudder 1958, RMB), Little
Cayman (RMB).

Prytanes minima (Guerin)

Small (2.5-3), reddish brown. Third antennal segment (males in particular) some
what thickened. Hemelytra variegated. Legs uniformly pale yellow.
Grand Cayman and Cayman Brac (Scudder 1958, RMB).

Prytanes formosa (Distant)

Body relatively elongate, head acuminate, clothed with decumbent sericeous
hairs. Anterior pronotal lobe convex, not higher than posterior lobe and considerably
narrower. Antennnae prominent, first, third, and fourth segments uniformly dark
brown, second segment paler.
Grand Cayman (RMB).

Prytanes dissimilis (Barber)

A relatively robust, moderately large species for the genus (3.5 mm or greater).
Scutellum frequently bicolored. Posterior pronotal lobe usually with a median dark
stripe. Subdistal ends of middle and hind femora in part dark red-brown.
Cayman Brac (RMB).

Froeschneria piligera (Stal)

Large, robust (7-8) with a deep transverse pronotal impression. Abdominal strid
ulitrum well developed. Body surface with numerous elongate upstanding hairs.


March, 1998

















Baranowski & Slater: Cayman Island Lygaeidae


Head, anterior pronotal lobe, scutellum, and ventral surface black, hemelytra black
and dull brown with a transverse macula.
Cayman Brac (RMB).

Ligyrocoris litigiosus (Stal)

Medium sized with a distinct lunate abdominal stridulitrum. First antennal seg
ment pale, fourth antenna segment completely dark. Legs and antennae dull yellow.
Femora spotted distally.
Grand Cayman (RMB).


Myodocha unispinosa Stal

Relatively large (8) with very elongate "neck." Head and neck, shining black.
Forefemur slender with a single large spine present. Antennae brightly colored, first
segment red-brown, strongly shining, contrasting with pale yellow second segment.
Grand Cayman (RMB).


OZOPHORINI
Ozophora umbrosa Slater

Moderately large (5.5-6.5), generally dark chocolate brown with pale spots on co
rium; membrane lacking pale apical macula. Dorsal surface glabrous. Fourth anten
nal segment with a conspicuous white annulus.
Scudder (1958) reported Ozophora atropicta Barber from the Caymans. Despite
our rather extensive collection of Ozophora species, we have been unable to collect
this species on the Caymans. We have recently examined part of the Scudder mate
rial, which is deposited in the Natural History Museum (London-not Oxford as the
Scudder paper states). These specimens are 0. umbrosa Slater, a species not described
at the time of Scudder's paper. We are thus referring the Caymans records of 0. atro
picta here.
Little Cayman (Scudder 1958, RMB) Cayman Brac (RMB).


Ozophora burmeisteri (Guerin)

Pronotum nearly uniformly black or dark chocolate brown. Posterior pronotal lobe
with yellow streak midway between meson and margin or a pair of yellow spots in
same area. Fourth antenna segment with conspicuous white annulus, 3rd segment
slightly swollen distally and dark chocolate brown on distal 13. Readily distinguish
able by the combination of its very dark pronotum and erect dorsal hairs.
Grand Cayman (Scudder 1958, RMB), Cayman Brac (Scudder 1958, RMB).


Ozophora carol Slater & Baranowski

Body elongate, relatively stout; head, anterior pronotal lobe and broad rays ex
tending through posterior pronotal lobe dark red brown. Anterior pronotal color
broadly pale yellow on either side of median red brown spot. Scutellum chiefly dark
red brown, but with raised elliptical calloused area yellow, shading anteriorly to red
dish brown. Antennal segments I, II, and III pale yellow with distal end of III, proxi
mal end and distal 34 of IV contrastingly dark chocolate brown. Body nearly glabrous
above, lacking conspicuous upstanding hairs.

















Florida Entomologist 81(1)


Grand Cayman (RMB).

Ozophora coleoptrata Slater

Small (3-4.5), chiefly dark chocolate brown with contrasting pale yellow bands on
the posterior pronotal lobe, and on the cubital vein of the clavus. Legs and antennae
uniformly pale yellow. Dorsal surface possesses numerous upright hairs. Color varies
considerably with some specimens pale yellow laterally on the corium.
Slater (1990) described this species from a series consisting only of coleopteroid in
dividuals with the clavus and corium fused and the membrane reduced to a small flap.
We have collected immatures on Grand Cayman that molted to macropterous adults.
The macropterous form differs from other small (3-4.5) Ozophora in having sparse up
right hairs on the dorsum.
Grand Cayman (RMB), Cayman Brac (RMB), Little Cayman (RMB).


Ozophora laticephala Slater & O'Donnell

Small (2.8-3.3), short, stout. Generally pale yellow with the posterior pronotal lobe
and most of the hemelytra contrasting with the dark anterior pronotal lobe, the latter
having pale white or yellow lateral margins. Bucculae U-shaped, rather than V
shaped as in other Caribbean species of Ozophora.
Grand Cayman (RMB) and Cayman Brac (RMB).


Ozophora minuscule Scudder

Moderate sized (4.3), markings somewhat similar to 0. pallidifemur, but much
smaller. Known only from the type series consisting of two males collected in a light
trap near Georgetown. Dr. Peter Fitzgerald operated a blacklight trap for us for sev
eral years but never collected this species.
Originally described and known only from Grand Cayman (Scudder 1958, BMNH).


Ozophora pallidifemur pallidifemur Scudder

Moderate sized (5-5.5), predominantly dark brown with uniformly pale yellow
legs. Antennal segments I, II, and III pale with distal ends of II and III darkened.
Fourth antennal segment brown with white subbasal annulus. Membrane uniformly
dark.
Originally described and known only from Grand Cayman (Scudder 1958, BMNH,
JAS, NMNH, RMB).


Ozophora pallidifemur fuscifemur Scudder

Similar to nominal 0. pallidifemur, but can be separated by the dark brown legs.
Originally described as a distinct species. Slater (1987) reduced this taxon to a
subspecies of 0. pallidifemur on the basis of each being endemic on separate islands.
Cayman Brac (Scudder 1958, RMB), Little Cayman (Scudder 1958, RMB).


Ozophora quinquemaculata Barber

Moderate (5-6) sized, relatively stout with strongly variegated light and dark
markings on pronotum and hemelytra. Posterior pronotal lobe with three dark long


March, 1998

















Baranowski & Slater: Cayman Island Lygaeidae


tudinal stripes, the median one occurring as a broad lobe along the meson, lacking a
pale streak. Apical corial margins dark distally from inward extension of dark apical
corial macula completely over raised corial margin apex.
Grand Cayman (RMB).


RHYPAROCHROMINI
Dieuches armatipes (Walker)

Large, robust (9 10), variegated with chocolate brown to black and light yellow to
almost white. Pronotum with broadly explanate pale lateral margins contrasting
strongly with the predominantly dark remainder of pronotum. Scutellum with a pair
of small yellow spots. Hemelytra variegated, with a complete transverse dark fascia
and large oval elliptical white subapical corial macula.
This African species apparently has recently become established in the Western
Hemisphere. It was first reported from Grand Cayman and St. Kitts and from inter
cepted specimens from the Dominican Republic and Jamaica by Henry and Froe
schner (1993). It is also now known from the Florida mainland.
Grand Cayman (Henry and Froeschner 1993, RMB) and Cayman Brac (RMB).


ACKNOWLEDGMENTS

We thank Mrs. Helen Baranowski for her assistance in collecting many of the spec
imens discussed here; Mrs. Holly Glenn, Ms. Julieta Brambila, Tropical Research and
Education Center, for assistance in mounting, labeling, and curating the collection;
Dr. Peter Fitzgerald, Grand Cayman, and Mr. E. A. Dilbert, Cayman Brac, for operate
ing blacklight traps for us. We also thank Dr. A. G. Wheeler, Clemson University and
Ms. Wendy Meyer for critically reviewing the manuscript. Florida Agricultural Exper
iment Station Journal Series No. R-06114.


REFERENCES CITED

ALAYO, P. D., AND H. GRILLO. 1982. El genero Ischnodemus Fieber (Heteroptera: Lyg
aeidae: Blissinae) en Cuba. Centro Agricola 9: 51-63.
ASKEW, R. R. 1994. Insects of the Cayman Islands. In: M. A. Brunt & J. E. Davies
(eds.). The Cayman Islands: Natural History and Biogeography, 333-356. Klu
wer Academic Publishers, The Netherlands.
BARBER, H. G. 1953. The genus Pachybrachius in the United States and Canada with
the description of two new species (Hemiptera: Lygaeidae). J. New York Ento
mol. Soc. 60: 211-220.
BRUNT, M. A., AND J. E. DAVIES (eds.) 1994.The Cayman Islands: Natural History and
Biogeography. Kluwer Academic Publishers, The Netherlands. 604 pp.
DALLAS, W. S. 1852. List of the specimens of Hemipterous insects in the collection of
the British Museum. Pt. II London: Taylor & Francis. pp. 369-592.
FROESCHNER, R. C. 1983. Heteroptera records from the Grand Cayman Island. Proc.
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mol. Soc. Washington 95: 449-452.
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Florida Entomologist 81(1)


ORGANIC MULCH AS A FACTOR IN THE NYMPHAL HABITAT
OF MYNDUS CRUDUS (HEMIPTERA: AUCHENORRHYNCHA:
CIXIIDAE)

F. W. HOWARD' AND C. OROPEZA2
1University of Florida, Fort Lauderdale Research & Education Center
3205 College Avenue, Fort Lauderdale, Florida 33314 USA

2Centro de Investigaci6n Cientifica de Yucatan, Apartado Postal 87, Cordemex 97310
Merida, Yucatan, Mexico

ABSTRACT

Certain types of organic mulches spread on the ground in a palm planting with St.
Augustine grass, Stenotaphrum secundatum, ground cover enhanced the habitat for
the nymphal development of Myndus crudus Van Duzee, as measured by the greater
numbers of adults emerging from mulched areas compared with controls. Plots
mulched with chopped and shredded coconut fronds had greater numbers of M. cru
dus than controls. Higher numbers of M crudus emerged from plots with pine bark
mulch than from control plots. There were no significant differences in mean numbers
of adults captured in plots with eucalyptus and pine bark mulch. The least numbers
of adults emerged from plots mulched with pine bark nuggets. Myndus crudus
nymphs were never in the open but always beneath pieces of mulch. The benefit of
mulches to the insects appears to be that of providing shelter.

Key Words: Myndus, Cixiidae, Fulgoroidea, palm, lethal yellowing, cultural control


March, 1998

















Howard & Oropeza: Myndus crudus and Organic Mulches 93

RESUME

Ciertas classes de cobertura organica dispersada sobre el suelo en un plantio de pal
meras con past de San Agustin, Stenotaphrum secundatum, mejoraron el habitat
para el desarrollo de las ninfas de Myndus crudus Van Duzee, como fue estimado por
el mayor nfimero de adults emergidos de estas areas en comparaci6n con testigos.
Parcelas con frondas de cocotero picadas y ralladas tenian nfimeros mayores de estos
insects que los testigos. Un mayor numero de M. crudus emergi6 de parcelas con cas
cara de pino picada en comparaci6n con los testigos. El promedio de adults capture
dos en parcelas con cobertura de eucalipto y de cascara de pino no difiri6
significativamente. Las ninfas de M. crudus nunca estuvieron al descubierto, sino
siempre debajo de los fragments de cobertura. El beneficio de las coberturas organic
cas para M. crudus parece ser el de proveer abrigo.





Myndus crudus Van Duzee (Hemiptera: Auchenorrhyncha: Cixiidae), a widely dis
tribute planthopper in the American tropics (Howard et al. 1984, Kramer 1979, Vil
lanueva Barradas 1991), is a vector of lethal yellowing of palms (Howard 1987,
Howard et al. 1983). Lethal yellowing is a fast-spreading, destructive disease associ
ated with a phytoplasma to which at least 35 species of Palmae are susceptible, in
cluding the economically important coconut palm, Cocos nucifera L., and date palm,
Phoenix dactylifera L. The disease has long been known in western islands of the West
Indies, from where it apparently invaded Florida (US.A.) and Mexico (Howard 1983,
Howard et al. 1984, Villanueva Barradas 1991). It has recently spread to Belize and
Honduras (Ashburner et al. 1996). Thus far, there is no evidence implicating any in
sect species other than M. crudus as a potential vector of lethal yellowing.
The nymphs of M. crudus develop at or just under soil level on grasses or sedges,
and the adults feed on palms (Howard & Villanueva-Barradas 1994, Eden-Green
1978). At least 37 species of grasses (Graminae) and 4 species of sedges (Cyperaceae)
have been reported as nymphal hosts of M. crudus (Carrillo Ramirez & Pina Razo
1990, Howard 1989, Howard 1990a, Howard 1990b, Pina Quijano 1993, Tsai & Kirsch
1978, Villanueva B. et al. 1987, Zenner de Polania & Lopez A. 1977). When rearing M
crudus, Eden-Green (1978) observed that the nymphs were often hidden beneath
pieces of coconut fiber. Therefore, we decided to determine whether coconut fiber and
similar materials spread on soil among nymphal hosts would improve the habitat for
M. crudus nymphs, as estimated by the numbers of emerging adults.


MATERIALS AND METHODS

The study was conducted at the Fort Lauderdale Research & Education Center in
a 0.6 ha grove of 100 coconut palms and other susceptible species of palms. St. Augus
tine grass, Stenotaphrum secundatum (Walt.) Kuntze, a preferred host of M. crudus
(Howard 1990b), was the predominant ground cover. Plots (2 x 2 m) selected at ran
dom were not mowed or otherwise disturbed during each experiment.
In the first experiment, which was initiated February 1994, a mulch was obtained
by passing coconut palm fronds through a mechanical brush chipper. This material
consisted of fine shredded fragments and larger pieces of variable size between 2-5 cm
in width and 5-10 cm in length. The material was spread on each of 6 plots (0.05 m3/
plot) and raked lightly so that it settled on soil and allowed the grass blades to
emerge. Six similar plots where fiber was not spread were selected as controls.

















Florida Entomologist 81(1)


In May 1994, traps were used to sample adults emerging from the plots. Traps con
sisted of 60 x 60 x 50 cm plywood boxes. Polypropylene funnels of 5 cm dia and 0.5 cm
mouth were fitted over an opening at the center of the top of each box. Transparent
plastic test tubes (2.1 x 10 cm) were placed over the funnel mouths. Adults that
emerged from the plants attempted to exit through the funnel opening and thus were
captured in the tubes and counted.
Emergence traps were placed simultaneously in the center of each of 6 plots with
coconut fiber and 6 control plots. Just prior to placing a trap, the grass was agitated
vigorously for several minutes to repel any adult Auchenorrhynchous insects from the
sample area. Additionally, any adults captured in traps during the first 24 hours were
removed and not counted in samples. The traps then remained in place for 1 week, af
ter which the numbers of male and female M. crudus captured in emergence vials
were determined.
In the second experiment, initiated February 1995, the effect of the following ma
trials on the nymphal habitat for M. crudus were tested: (1) pine nuggets, (2) pine
bark mulch (Hyponex Corporation, Marysville, Ohio), (3) cypress mulch (Greenleaf
Products, Inc., Haines City, Florida) and (4) eucalyptus mulch (AACTION Nursery
Products, Inc., Fort Myers, Florida). The length and width of 10 of the larger frag
ments were determined for each type of material. The materials were spread as in the
first experiment in 6 plots per material, with 6 control plots.
Adult M. crudus emerging from plots were sampled during June -July, 1995. In
each plot, an emergence trap was placed successively for 4 days each in the NE, NW,
SW, and SE quadrants, and M. crudus female and male adults captured were counted.
Plots were closely examined for M. crudus nymphs for 2 hours on the afternoon of
October 12, 1995. Grass stolons were carefully parted to examine soil surfaces of
about 400 cm2 at a time, and mulch fragments were lifted to examine the soil surface
beneath them.
Data of the experiment with coconut fiber were analyzed by Student's t-test and of
the experiment with several types of mulch with Analysis of Variance and the Waller
Duncan Bayesian k ratio t-test (SAS Institute 1985).

RESULTS

A mean of 4.16 (SEM = 1.74) adults were captured in emergence traps from plots
mulched with coconut fiber, compared to 0.17 (SEM = 0.17) adults from control plots
(P 0.05, t = 2.29). The total of 25 adults captured from mulched plots included 18
males and 7 females.
In the second experiment, the numbers of M crudus adults captured varied among
mulch types (F= 4.08, df4, 115, P< 0.05)(Table 1). More adults were captured in plots
with pine bark mulch than from plots with cypress mulch, pine bark nuggets or the
control plots. The highest numbers of M. crudus resulted from plots with pine bark
mulch and eucalyptus mulch. Similar numbers of M crudus resulted in plots with cy
press mulch, pine bark nuggets and the control plots.
There were differences between mulch types in lengths of pieces (F = 13.5, df 3, 36,
P < 0.0001). Based on the length and width of the largest pieces, pine bark nuggets
was the coarsest of the materials in the second experiment, followed by pine bark
mulch, eucalyptus mulch, and cypress mulch (Table 2). Pine bark nuggets consisted of
large pieces of bark with almost no fine material. All the other materials consisted of
about equal volumes of large pieces and fine fibrous material.
During the 2-hour examination of plots on October 12, a total of only 10 M. crudus
nymphs were observed. All were beneath fragments of mulch. Nymphs occurred sin
gly or in groups of up to three.


March, 1998


















Howard & Oropeza: Myndus crudus and Organic Mulches 95

TABLE 1. MEAN NUMBERS OF M CRUDUS ADULTS CAPTURED IN EMERGENCE TRAPS IN
PLOTS WITH DIFFERENT TYPES OF MULCH.

Mean' number of M. crudus adults
Mulch material captured Standard Deviation

Pine bark mulch 3.04 + 3.20 a
Eucalyptus mulch 2.00 + 2.48 ab
Cypress mulch 1.71 + 1.97 b
Control 1.08 + 1.41 b
Pine bark nuggets 0.75 + 1.03 b

1Means within a column followed by the same letter are not significantly different (P < 0.05, least significant
difference.)


DISCUSSION

The higher numbers of adult M. crudus emerging in plots with certain types of or
ganic mulches probably reflects higher numbers of nymphs in these plots. It is not
known whether this was due to (1) preference of these microhabitats by ovipositing fe
males, (2) movement of nymphs into plots from adjacent areas, or (3) a greater rate of
survival in plots. In any case, the fragments benefit the nymphs of this species by pro
viding shelter.
Possibly, organic mulches may also benefit nymphs indirectly by improving the
soil, thus the quality of host plants. The principal benefit to plants of wood mulches is
in improving water retention of the soil, thus increasing the availability of water and
reducing the rate of leaching of nutrients. The nitrogen content of wood mulch is gen
erally about 0.09% and release of nutrients due to decomposition is extremely slow
(Anon. 1994). Release of nutrients from decomposing organic mulch may be important
to plants over long periods, but probably would have been insignificant during the pe
riod of this experiment.
Based on evidence from the first experiment, that coconut frond mulch enhanced
the ground habitat for M. crudus development, we expected that any organic mulch
would have similar effects. However, other materials differed in this respect. Fewer
M. crudus adults developed to adult in the coarsest (pine bark nuggets) and finest (cy
press mulch) materials than in the materials of intermediate sizes. Whether these dif


TABLE 2. MEAN WIDTHS AND LENGTHS OF FRAGMENTS (EXCLUDING FINE FIBER) OF DIF
FERENT MULCH TYPES TESTED FOR ENHANCEMENT OF M CRUDUS NYMPHAL
HABITAT.

Mulch type Mean width + SD1 Mean length SD

Pine nuggets 3.190 1.15 a 6.1 + 2.22 a
Pine bark mulch 1.620 + 0.69 b 5.5 + 1.28 a
Eucalyptus mulch 0.950 + 0.62 c 3.4 + 1.07 b
Cypress mulch 0.840 + 0.31 c 2.4 + 1.02 b

1Means within a column followed by the same letter are not significantly different (P < 0.05, least significant
difference.)




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