White-fringed beetles

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Material Information

Title:
White-fringed beetles distribution, survey, and control
Physical Description:
19 p., 6 p. of plates : ill., maps ; 27 cm.
Language:
English
Creator:
Henderson, C. F
Padget, L. J
United States -- Bureau of Entomology and Plant Quarantine
Publisher:
U.S. Department of Agriculture, Agricultural Research Administration, Bureau of Entomology and Plant Quarantine
Place of Publication:
Washington, D.C
Publication Date:

Subjects

Subjects / Keywords:
White-fringed beetles   ( lcsh )
White-fringed beetles -- Control   ( lcsh )
Genre:
federal government publication   ( marcgt )
non-fiction   ( marcgt )

Notes

Statement of Responsibility:
by C.F. Henderson and L.J. Padget.
General Note:
Cover title.
General Note:
"E-779."
General Note:
"June 1949."

Record Information

Source Institution:
University of Florida
Rights Management:
All applicable rights reserved by the source institution and holding location.
Resource Identifier:
aleph - 030295130
oclc - 780180955
System ID:
AA00025188:00001

Full Text
LiLBPK\Y
STATE PLANT BOAIIU)


June 1949



WHITE-FRINGED BEETLES
DISTRIBUTION, SURVEY, AND CONTROL

By C. F. Henderson and L. J. Padget
Division of Domestic Plant Quarantines


United States Department of Agriculture
Agricultural Research Administration
Bureau of Enromology and Plant Quarantine


E-779






LIBRARY
STATE PLANT BOARD

WHITE-FRINGED r.'.CTLES
DISTRIBUTION, SURVEY, AND CONTROL

By '. F. Hc rson and L. J. Padget,
Division of Domestic Plant Quarantines


A r-;ce of while-fr'".ged h-etles, G aphognathus leucoloma fecundus
(Buch.), was first r, -rted in the United States in September 1936, when
adult specin.ens si.l ':,Ltted by A. N. Tissot of the Florida Agricultural
Experiment Station were identified in the Bureau's Division of Insect
Identification. Later in that year the beetles were found in northwest
Okaloosa County, Fl ., where they were causing appreciable injury to
peanuts. Beetles also were found in northern Walton County, Fla., and
in contiguous area-, in Covington and Geneva Counties, Ala. The first
investigations on the economic importance of white-fringed beetles were
made in May 1927, by J. R. Watson of the Florida Agricultural Experi-
ment Station and U. C. Loftin of the Bureau of Entomology and Plant
Quarantine. The-': studies indicated that the larvae were causing ap-
preciable damao, to cotton, corn, peanuts, velvetbeans, and other crops
grown in areas mentioned. Other closely related species and races
of Grphognathus were subsequently found also causing economic damage,
and all are collectively ref- -red to as white-fringed beetles.
Subsequent to these preliminary investigations, delegations of ento-
mologists and insect pest control officials from a number of widely
separated States then visited the infested area, and as a result of their
studies and observations they concluded that white-fringed beetles were
a serious threat to a wide range of cultivated crops grown in many of the
agricultural areas of the United States.
In July 1937 the Bureau of Entomology and Plant Quarantine, the State
Plant Board of Florida, and the Alabama Department of Agriculture and
Industries r!etermined that a cooperative white-fringed beetle control
project should be established immediately. This work was organized
under the supervision of the Division of Domestic Plant Quarantines in
the Bureau of Entomology and Plant Quarantine. The purposes of this
project were to reduce populations by the application of suitable control
measures and to prevent further spread by effective quarantine action. In
the same year a research project in the Division of Cereal and Forage
Insect Investigations was established to study the biology of the beetles
and obtain other pertinent information necessary for controlling these
in ects and preventing their further spread.

ECONOMIC IMPORTANCE

White-fringed beetles cause serious damage to many field crops of
* Imic importance in the Suutherrn States (figs. 1 and 2). Most of the
dam;-_,t: is done lby the larvae, which feed on the roots of pr-,ctically any






















Figure 4.--Pupa in soil cell.


F------ -


Figure 5


-Adult.


Figure 6.--Egg masses cemented to twig.


Stages of the White-fringed Beetle Graphognathus leucoloma fecundus.


Fifcure 3.--Larvae.






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insect would impose a hazard on agriculture and levy a heavy toll on the
production of susceptible crops.

DESCRIPTION

White-fringed beetle larvae are approximately one-half inch long
when full-grown, strongly convex, yellowish white, legless, and picaly
weevil in form (fig. 3). The head is slightly darker an;- partially retracted
into the body. It bears two stout black mandibles, which it uses in fe, d-
ing on the roots of plants.
The pupae are approximately seven-sixteenths of an inch in length
and are immobile except for the abdomen (fig. 4).
Adult beetles are approximately seven-sixteenths of an inch in length
and about five thirty-seconds of an inch across the abdomen, brownish
gray in color, with a lighter band along the margins of the wing covers
(fig. 5). The common name of the insect is based on this lighter band.
Two paler longitudinal lines also occur on each side of the thorax and
head, one above and one below the eyes. The body is densely covered
with very short hairs; those on the wing covers are somewhat longer.
The snout is short and stout and bears clubbed antennae. The under-
wings are rudimentary, and the basal margins of the wing covers are
fused to the mesonotum. The beetle is thus unable to fly.
The eggs are oval in shape and a little more than one thirty-second
of an inch in length. They are milky white when freshly deposited but
turn to a dull light yellow after 4 or 5 days (fig. 6).

LIFE HISTORY

Larvae are usually found in the upper 9 inches of soil, where they
are in contact with or close to the roots of food plants. They are nearest
the surface during March and April. At maturity the larvae go through
a short inactive stage and then form cells in the soil, where they remain
quiescent for several days longer before transforming into pupae.
Pupation generally occurs during May, June, or July, the time varying
with locality and climate. However, some nonfeeders remain in the soil
for a year or more as carry-over larvae. The pupal stage is of 8 to 15
days' duration, after which the skin is molted and the young adult remains
in the pupal cell for several days, enabling the body wall to harden.
Adult beetles begin to emerge early in May and continue to emerge until
mid-August, the time depending upon species, locality, and climate.
Emergence fromthe ground usually takes place after a rain. The beetles
feed on leaf tissue for several days and then begin oviposition.
E31s are deposited in masses of 15 to 25 cemented to sticks, d.-bris,
or soil, and are partially concealed by fine particles of soil. They hatch
in approximately 2 weeks during warm weather when -.-Lfficient moisture
is present. Eggs have been kept viable for more than 7 months when






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held in a dry condition. The total number of eggs deposited is dependent
upon the food plants on which the adult feeds. Beetles feeding on grass
deposit only a few eggs (from 15 to 60), whereas leguminous plants such
as peanuts and velvetbeans are conducive to heavy oviposition (1,500 or
higher). Adults live for 2 or 3 months, and egg laying continues inter-
mittently throughout most of this period. The insects pass the winter
in the soil as small to half-grown larvae, except for the few full-grown
carry-over larvae as described above. The life cycle is shown infigure 7.
White-fringed beetles are parthenogenetic. No males are known, and
every adult is a female capable of producing viable eggs. A single beetle,
therefore, or any egg or larvae may establish a new infestation wherever
environmental conditions are favorable.


Figure 7.--Life cycle of the white-fringed beetle.
























Information for this circular has been drawn from life-
history studies made by the Division of Cereal and Forage
Insect Investigations; data on the South American distribution
of white-fringed beetles collected by the Division of Foreign
Parasite Introduction; treatment methods worked out by the
Division of Control Investigations; taxonomic determinations
made by the Division of Insect Identification; and information
on domestic distribution, survey, and control assembled by
the Division of Domestic Plant Quarantines.





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GEOGRAPHICAL DISTRIBUTION

White-fringed beetles occur in Argir-jtina, Chile, Urugua., and T ,i.
In Chile their range is almost cr!1tit,.-,-us from the irri-, district of
La Serena in the north to the vicinil. f 1, in th outh In ..
they are found from Juju:, and Santi-.:. -1 I ste., and ossi ly f.t r
north, to the provinces of San Juan, La ;-'ampa, an I Rio NI :, ',i ',
south. The beetles are genr rally distribute, over U ,, i are fo
in limited numbers in Brazil in the state ,.f i.o Gr-.: de :'
have also b:en identified fro.m New South Wales, -f.,.-tralia,
probably are not native.
White-fringed beetles were probabi-.- i'Itrodu_:,. 2'.' U '-.-d ..t t
at one or more ports in shipments fr,:.n. the South A:-ric,..; c .ent.
After their discovery in Alabama and Florida in 1936, sco .- ins.:-
tions in 1937 at ports of entry and ahlor.; railroad x ights-'-way and
other arteries of transportation reve.-led the pres. e of i se insects
in Louisiana and Mississippi. In 1942 they were found in l'orth C .' '
at Wilmington, in the course of regular scouting activities. In 1-'6 l:.-
festations of white-fringed beetles were discovered in Geor 4ia near
Eastman, Fort Valley, and Macon. The Georgia infestations were found
not only on general cropland and on residential and industrial sites, but
also in large ornamental nurseries. Inspection of properties landsc. i_ ']
with ornamentals obtained from these nurseries disclosed ,.;y adJitional
infestations in Georgia, one in South Carolina, and two in Aia',jma, The ,
finding of widespread infestations in nurseries and ornamental plantings
introduced a new approach to the technique of survey procedur.:s--
namely, tracing the movement of articles capable of dissemination: the
insect which were shipped from newly discovered infested p- rties
and thereby possibly locating additiornaLl infestations. In 19 -L.. -
fringed beetles w,-rv found in T ,nes -,:, in -. city of .. > .s. ce
Graphognathus leucolona fecund .,. :I...-. cred in his cou' r
species and races of Graphognathus ive .,.n foumd which also
economically important and are distril.,ted as follows (F:. 8):

leucoloma dubius (Buch.) leucoloma imitator Buch.: p,-r -: iriu (:--.ch.-
Alabama North Carolina : )-Th1ama
Florida Florida
Mississippi leucoloma pilosus (Buch.): Louisiana
North Carolina Alabama Mississippi

leucoloma fecundus Buch.: leucoloma striatus (Buch.):
Alabama Alabama minor (Buch.)-
Florida Florida Florida
Louisiana Georgia
Mississippi Louisiana
Mississippi
South Carolina
Tennessee





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oJoDlOC i1!

i Known infested oreas.


T owe imts of
in onnuof temperre
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Figure 9.--Distribution of the wh-ite-fr:*r-,_',:] beetle in ;.,uth -erica


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IOTHEOWS OF APPARMT UWT AM LOMB UIaWU OFa

--- JUPIKUA SWE ITED AMe XT f rUTTW
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--------------- ----- ^ --------- ^ ---~ ^ ------ Ws o^ M


Figure 10.--Probable areas in North America adaptable to white-
fringed beetle development.






-9-


;n sur-,_y conducted sin,'e 19.7, apr:ro'i ate ...y 24d '.r acreS in > ..se
.Stats Lave becr foLwid to be infested.
-1e pe'--^ntial r- ,ge in the United Stats was esl" -,iil-, I.v studi .{
geogrc,-'.c and *:lirr,Atic 16at- coli -c-?d f:oir S.-uth America, the activee
omce -.f *k'tct-fr:"T.:-,d b-ctles, in relation t. the kno.a. c, .,.tr button ,:*,
th,' C .,t".-.. 7=- -ncwn south.-rn limit of the .- tics in .uith America
is s I ."*" I.i. "-- '-'' 'iegrf-es (fi 9). In he .o. o .e.o n HI. i.phere thi
or.'. f, ... ..1.'it *. of -''*.: ,.,., P !f 7. 0; 1T nTrthe n

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i.m .. -,-..^ '." ..-'". t', i. 3 to 2'.. ..... ,rees, co -. s. :.,.,c, in r -.rr m i-
^p h r '. l 'o r _"I i;, .h"-.' .'" ." t' .. .*''*J" -'" o r id a : _' J i-i a .

corre ^i-.'- ,: ..',,-pro.1i i.. teiy tc '.I<, 70 U i.-.c -1: -in. '. "orth ,I ..^riia
T.a'.. t -,_.:rn t"eU G' f Coast i.er lim it : n -en .
corr .. 57 iso.v-erm I _. .i St: thi ,e
an -,Lrn Gul f"1!A~ r!~c I-e
*.nnr',: t1"r r'- -"a. ,..!".' is a'pr,"xi'"; ei';, *th '. of W asI'J _ton, C.
',- e.ice-e dica~ es t:.a*.' i.J sted area. a,.- :, ...." Coast
are '-,'y the c.' ert:inc.-i ich thie beetles :..' t a J t '- m
selves i. *..rt" A..erica. No rthi. a: *?, th.y rig'., ex, ,d to .- latitude
of Was' ngtnri, D. C. However, ie:r a,-,:.l ter:.-pc.; .re and latitude
ranges may net be the .nly fac tors '!--t iru luence t-,- d li 'i ; tion. f
type, -:oil ferperaturu -''ur.:.ng the winter, auid land us.-;ge in may also be
irnpc.-taint. P.:' f:-dl i.-s 'robabi" scondlry, 83 the precipit:.ti:.r r:.- _.es
fronm '?s thar 20 i;,ich'hs to more than 130 incs per '.-'r in iJferent
parts of Chile kncwn to be inhabited by these beetles.
QUARANTINES AND ,SUPPORTING MEASURES
FOR PREVENTING SPREAD OF BEETLES
Quarantine regulations against white-fringed beetles were promul-
gated by the Federal Government and the various States involved scon
after the discovery of this pest. State plant quarantine: were initiated
for restricting intrastate movement from infested areas of materials
believed capable of spreading the insects. A Federal domestic plant
quarantine was also promulgated, effective January 15, 1939, to restrict
the interstate movement of articles believed capable of disseminating
the beetles.
These early quarantines were prohibitive rather than restrictive in
nature, as information was meager on the biology and habits of these
insects. The quarantines were revised from time to time with the
accumulation of additional information about the beetles and their sus-
ceptibility to insecticidal and fumigation treatments.
Although the beetles do not fly, prevention of spread is made exceed-
ingly difficult by the cosmopolitan feeding habits of the insects, their
close association with roots and soil, the tendency of the adults to con-
ceal themselves when disturbed, the wide range of carrier materials,
the volume of movement from large areas throughout the year, and the
numerous channels of possible spread. When it is considered also that
any individual egg, larva, pupa, or adult can start an infestation in a new






-10-


locality, it is seen that only by stringent quarantine measures aided by a
drastic program of population suppression at shipment or movement
sources can we hope to be successful in preventing dissemination.
Quarantine procedures are not the only safeguards for preventing the
spread of infestation. The insects may inadvertently be disseminated
by the ordinary movements of man from public gathering places such as
schools, shipping points, processing plants, and railroad yards. The
adult beetles may crawl into vehicles located in such areas and be
distributed by these means. Therefore, in addition to quarantine pro-
cedures, insecticides are applied around such places to reduce popula-
tions and minimize the danger of spread.
Transportation of soil is one of the most likely means of dissemi-
nating white-fringed beetles. The insects spend the greater portion of
the year in the soil as larvae; eggs, pupae, and general. adults may also
be found in the soil at certain seasons of the year. The movement of
nursery stock and other plants with soil is especially dangerous, because
the larvae are usually found close to the roots. As a basis for certifica-
tion bare-rooting is resorted to, especially in those plant species having
matted root systems. Larvae may be completely removed by thorough
washing of these roots, or destroyed in soil balls up to 16 inches in
diameter by fumigation with approved dosages of methyl bromide.
DDT broadcast at the rate of 50 pounds per acre as a dust or as a
suspension spray and immediately worked into the soil by disking or
cultivation will eliminate white-fringed beetles. A treatment of this type
may be applied in nurseries, and plants grown in soil so treated are eligible
for certification without further treatment. However, since a few large
larvae which are difficult to kill with DDT may carry over to the next year,
the nursery stock may not be certified until after two adult-emergence
seasons. The single 50-pound soil treatment is supplemented during the
first season with multiple spray applications at one-half pound of DDT
per acre. Potted plants grown in sterilized soil containing DDT at the
rate of 1 ounce per cubic yard are also eligible for certification.
The larvae are also likely to be transported in uncured bulbs, tubers,
and corms of ornamental plants unless properly treated. The movement
of peanuts and peanut hay from infested areas is especially dangerous,
as this preferred food plant of the adult beetle is conducive to heavy
oviposition, and eggs are often deposited on the stems which are in
contact with the soil.
SURVEYS
One of the principal activities of the white-fringed beetle control
project is to conduct surveys for locating new infested areas and de-
limiting known infestations. These surveys are important adjuncts to
both quarantine and control activities, as the information gained there-
from is used to determine boundaries when establishing quarantine areas
and to ascertain the need for applying insecticidal treatments to infested
properties. Because of the importance of these surveys, considerable
attention has been devoted to developing methods of inspection for both
larval and adult white-fringed beetles.





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Inspection for Larvae

Inspections for larvae of white-fringed beetles are conducted early
in the spring, when vegetation is young and most susceptible to injury
by the root-feeding larvae. Discovery of a new infestation early in the
larval season not only serves as a basis for the immediate promulgation
of quarantine action, but also permits the inception of a control program
during the life of the beetle generation then present.
White-fringed beetle larvae are known to feed upon 385 species of
plants distributed in 41 orders. Since it would be impossible for person-
nel not thoroughly trained in taxonomic botany to become familiar with
all these plant species, and since inspection for larvae under so many
plants would be slow, tedious, and costly, a standard method of larval
inspection was established which has proved satisfactory. In the system
of survey thus devised five beetle relationships are taken into consider-
ation: (1) Likely areas, (2) favorable sites, (3) preferred plants, (4)
selective sampling, and (5) plant symptoms.
Likely areas.--From the points of introduction into the United States
white-fringed beetles spread along the various arteries of transporta-
tion and became established in other areas. Since railroads undoubtedly
played an important part in the early dissemination of the pest in this
country, railroad yards and industrial and processing plants were of
major interest in early inspection programs. The application of control
measures and the judicious enforcement of quarantines have minimized
railroads as a source of spread, and the larger infestations which were
established by such movement before the control project was begun have
probably been located by search along transportation lines. From a
survey standpoint, therefore, railroad yards, processing plants, and
community centers are now of less irAportance. Of primary importance
at the present time are locations to which materials capable of dissem-
inating infestations were moved from known sources of infestation prior
to their discovery. First consideration is accorded properties that have
been landscaped with nursery stock moved from areas of known infesta-
tion. In fields displaying loss of stand characteristic of white-fringed
beetle injury inspectors look for larvae in the soil around the roots of
dead, dying, and dwarfed plants. This approach may be considered as
the first step in surveying regions not known to be infested.
Favorable sites.--White-fringed beetle larvae occur more frequently
in certain ecological environments than in others. Most of the species
and races are seldom found in woods, swamps, or old-stand native
vegetation. When present in numbers, they usually occur on land that is
well drained and has recently been disturbed by cultivation or other
human activities. On farm land the inspector concentrates on cultivated
fields, pastures, and fence rows, rather than woody swampland. White-
fringed beetles are seldom found in well-kept lawns and, if present, occur
in such limited numbers that detection is difficult. Therefore, in resi-
dential areas the inspector limits his search to flower beds and shrubbery.







He also inspects undeveloped lots and aqlly'ays in the vicinity. Since
the amount of time that he can spend in an cone area is limited, the in-
spector gives special attention to the most ',.vorable beetle sites.
Preferred plants.- -Although white-fringp d beetles are known to feed
on several hundred species of plants, observations over a period of years
have disclosed that certain ones are preferred by the larvae. That is, in
random diggings under many different plants in an infested field, larvae
are found more frequently under one plant species than under another.
In a heavily infested field, of course, larvae may be present under prac-
tically every species of plant. Inspectors are thus instructed to use
selective diggings and to specialize on certain plants in preference to
others. These preferred food plants include practically all field and
garden crops and native vegetation such as dog:%ennri. Polypremum,
evening-primrose, goldenrod, ragweed, broomsedge, wild geranium,
plantain, wild lettuce, dock, Euthamia, sheepsorrel, and various briers.
Broomsedge and other perennials, such as dogfennel, which are favored
by the adult beetle as shelter plants, are carefully inspected, especially
during the early spring, as the adult often oviposits at the base of these
plants and larvae may be concentrated there.
Selective sampling.- -After an area has been geographically and
ecologically delimited, the acreage is still too large for digging every
preferred food plant that may be found thereon A selective sampling
is therefore made, in which preferred food plants are inspected in
representative portions of the land. Inspection of a field, for example,
might include examination of the soil under preferred food plants growing
in the shade of trees, in the direct sun, in the interior of the field, and
at its periphery. This method has been found more satisfactory than
sampling by digging under the preferred food plants every few feet
apart.
Plant symptoms --When young plants are attacked by larvae, they
may show certain abnormal symptoms, such a', willing, reddening, and
yellowing,. if all plant species thus attacked displayed symptoms quite
distinct from tiov, cause-d by other factors, in -'ection for larvae -.cLuld
be greatly _iiLn.PLiiied. Ho',-ever, the morbid plant ,,mptoms usually
associated with the larval activity of white-fr. 'ged beetles are identical
with these caused by several other agents. Furthermore, these symptoms,
when caused by white-fringed beetles, are sometimes displayed only by
low-growing or very young plants in the early spring and in heavily in-
fested. are..s, and they tend to disappear in those plants that survive.
Thus, 2,ic search for morbid plant symptoms cannot be considered a
co..irinuously valid method of larval inspection by itself. However, in
most areas it is useful during the early spring in limiting still fu-ther the
number of plants to be examined after the previously mentioned approaches
have been used.
In looking for larvae the inspector digs the plant up by the roots with
a hand trowel or a shovel, and breaks the soil apart. It is not necessary
to dig much dirt, as the larvae, if present, will be found on the roots or
nearby in the soil.






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Figure 11.--Characteristic white-fringed beetle larval damage
to Irish potatoes.














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Figure 12.--White-fringed beetle adult in characteristic feeding
position on peanut leaf.























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Figure 13.--Feeding signs of white-fringed beetle adults.


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-13-


Inspection for Adults

When inspection for adults is employed for locating or delimiting
infested areas, the various approaches described above under inspection
for larvae are also used. In addition, advantage is taken of two primary
instincts of the beetle, viz., its search for food and its urge for shelter.
After he has found a suitable environment, the inspector looks for pre-
ferred food plants showing characteristic feeding signs. The adult beetle
straddles the leaf margin, extends its head as far as possible, and cuts
the leaf edge. Then it draws the head downward, removing and ingesting
a marginal section of leaf tissue. When the head has completed the
maximum arc, it is again thrust forward, and another narrow strip is
cut and eaten in the same way. Individual feeding varies considerably,
but beetles not disturbed seem to eat away three or four such marginal
strips without changing position. The leaf area thus removed is approx-
imately one-quarter of an inch in length along the leaf margin and about
three-sixteenths of an inch deep. Such cuts are typical feeding signs,
but individual feedings may overlap, and a typical sign may be altered
or enlarged by additional feedings until the entire leaf from the margin
inward may be consumed. Figure 12 shows the insect in characteristic
feeding position. Typical feeding signs on a number of preferred food
plants are shown in figures 13 and 14.
Although these feeding signs are characteristic for white-fringed
beetles, they cannot readily be distinguished from those of some other
insects. However, these signs may be helpful to the inspector when
used in conjunction with preferred food plants occurring in a favorable
environment. When feeding is recent, the edge of the incised area will
be green or show only a slight discoloration, and the beetles may be
found attached to the plant or on the ground close by. Old feeding signs
show a marked discoloration along the periphery of the leaf. Since the
beetles spend part of the day under preferred food or shelter plants, a
search is made on or beneath these favored plants whether or not feed-
ing signs are noted. When disturbed the insects will often drop from
the plants and feign death, so that they are difficult to detect. Field
experience is an important asset to an inspector looking for adults, as
a knowledge of the insect's habits, reactions, and environmental prefer-
ences is of much value in this type of activity.
From a project standpoint, inspection for larvae is more profitable
than inspection for adults. The latter type of inspection is possible only
during a relatively short period of the year, when control activities
directed against adults are underway. Personnel of the project are
more efficiently utilized in inspections for larvae during the spring and
early summer before such control operations begin. During the control
season inspection for adults may be carried on between control operations
as a supplement to inspection for larvae.






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CONTROL

When white-fringed beetles were first discovered in this country,
little information was available on which to base a control program.
Various emergency measures were attempted but abandoned as being
outdated or impracticable. They included the use of barrier ditches,
trap crops, and flame throwers. As research data on the beetles were
accumulated, other methods of control proved to be more successful,
and operations against the pest were revised accordingly. Herbicidal
sprays, fallowing, and clean cultivation were found to reduce popula-
tions, but such treatments have been superseded by the use of insecti-
cides, which give comparable results at less expense.
All control work has been undertaken as a cooperative State and
Federal function to prevent or retard further spread of the beetle and
to protect crops in the infested area against loss.

Herbicides
A sodium arsenite-fuel oil herbicide is used to a limited extent
around important dissemination points, such as sales and shipping areas
alrd railwa.y sidetracks, where the hazard of spread is so great that even
light pcpuiations. are dangerous. The herbicide eliminates those species
of broad-leaved plants offering food and shelter to the insects and forces
trm ti-. other envirnrnkmnts. During this movement populations are dras-
tically reduced by exposure, and the beetles are also killed by contact
with the hnerbicide or from eating foliage sprayed with this poison. The
continued use of the arsenical herbicide results in a predominantly grassy
condition not conducive to large white-fringed beetle populations.
The employment of herbicides in recent years has been limited be-
cause of their high cost, their toxicity to livestock, changes in flora in
many previously treated areas, and low beetle populations now existing
in environments adapted to such treatment. Its use in the future will
probablyy be confined largely to railroad yards and sidings and to isolated
locations where the insects cannot be controlled by other methods.

Insecticides
.Th, use of irisectici.,_s has become the most important method of
cont roI, white-f.-', .d Le,-tles, recr-iuse :.' the vast acreage that may
be .ecilvely treated at (Impa'.;ativel low ..ist. Moreover, the pro-
duction crops is not interrupted as wrS ,i clean cultivation and fallow-
ing are p,'-actict .
SCatci;,, ars. :-'itc was the first insecticide employed against white-
friig- .lties; it was used to a limited extent as a dust in 1938. Since
t'- chemical causes b'uriing of leg..mn rr,,,us plants such as peanuts and
elve .... is extr-i 1 toxic to livestc'.k, it x'as replaced largely
b i1939. A-,e c' uite inaJc control operations Dos-
sib on very of est.: ,i.perty, as this ..-,:-cticide is not in-
uiioi to ost -l,.';.t lie and is relativIl.y n'ntoxic to liv_-st.ck.

























COCKLESUR- Xoanthum emrIcaGRM Welt


"'


ow
*.6.q

/


VELvt7 e l- -
$tiztb ofo or D rnet* 4w t


TEAWEE D-
Side rhombifolio L,


COFFEE WEED-(Sickis- Pod)
EMSli$to Tore (L.) Bri;ton & Rose


KUDZU VINe-
Pursrria Tf>hBEr90 **' (S4i It,


GOLDENROD- 'Soidego ep L.


.A 'P '


- <'. 'i SO (0011 L


S'WCfT rn ", **** -, ) .r.

Figure 14.--Feeding signs of white-fringed beetle adults.


TATE PLAY 'OA
ST ATE pL-AM- SOARE


/


. ; .
























"_,j ,._ "-T ~ a & ',rw ff t ", .** "
-Z 6


Figure 15.--Fleet of machines for applying
concentrated sprays from the ground.


'
p..


* 4
'. 'v


Figure 16. --Concentrated-spray machine in
operation.


Figure 17.--Airplane with special spray boom
for applying concentrated sprays for control
of white-fringed beetles.


L.






- 15-


The in:,e(ticides were originally applied as dust-,, but because of
frequ -'f rains duirir,' th. -,rintrol sea.;on they were superse' (4 by spra;'s.,
whic, ar mor, adhesive. Dilute upra'_ wi-rc' first e, ,ro .c bhut on-
centra- ri spr '*' 1 r veloped 1ich a. more sive :'c d
central f- spray b
I-t :- ;plied .Tt,.)re ,' ,.-*":.om ic all ecial c~f e f, r .. 1 '" c r'
, Yh, ra c: spt-"- i 1,.ve b'- :', v' ,c n us < 'c ivel in
all .:.:r.iol areas (>'" s. 15 and 16 .- o .s
successfuL-y for F; lyi : .-. nra, s ra a s .
been. dtvi'ed for tti? p .- -- (it- 17)
Control f.-: -'. d ,.ii-? e re greatly m7: d o
High mortalities of ad,.ts we: .- ob1 i : wi1 Caiu dm
olite sprays (or dusts und,-.r fav,.r._'-'..e we:.ther cri'" :'s), -'* r
populations of larvaI were not _:,rresliordlnc ly red'-,ed. It '. ess, -
to obtain very high mortality of adults to affect futu,,' populations of e ,
as the white-fringed beetle has a high r productive potr;.,I:al. DDT i ,'-.,c
to larvae as well as adults, and drastically reduces p,;jpulatirn: of larva,-
and holds them at low levels. Its use against %hite-frinc--d b c-tles shows
much promise, and many field studies have been undertaken to "ird the
most effective methods of applying it. Altho',-igh this woil- is ?ti.l in pro-
gress, much information has been obt-.ined which is :-,.._ used in lar 7e-
scale operations against the beetle.

Methods of Applying DDT

DDT may be used in white-fringed beetle Io,-t c.l as a soil treatment
or as a foliage application. As a soil treatment, or control for larvae, the
DDT is applied to the ground surface as a dust or spray and then incorpo-
rated into the soil by cultivating. As a foliage treatment, or control for
adults, the insecticide is applied to the foliage and ground as a spray and
is not subsequently worked into the soil.
Treatment of soil for control of larvae.--DDT is most effective when
applied as a soil treatment against the larvae. This is also an economical
method of treatment, since single 10-pound applications have remained
effective for the 5-yea' duration of tests still in progress. Moreover,
this type of treatment may be applied at a time of year when crops are not
grown, and when it will not interfere with farming practices. When applied
in the fall or early spring at the time of plowing or disking, the DDT may
be incorporated into the soil v'ith farm equipment in the course of regular
farming operations.
DDT soil treatments are app!ie" as susp-nsions or dusts, at the rate
of 10 pounds of DDT per acre. The su -penr-sions are applied as concen-
trated sprays by machine. They are ,--epared by mixing a wettable powder
containing 50 percent of DDT directly with water. The dusts are applied
by hand, or with a fertilizer 'd:stributo such as one attached to a standard:
grain drill. They are prepared by ii nr the 50-perccnt DDT with inc.
carriers to concentrations of 2.5 to 5 percent of DDT. Duz ts have b.. n
somewh t more effective than suspens.Jonr as soil t-rea'mn. T'" ayse
thoro.'.h-, incorporation of the DDT into the soil immediately after treat-
ment is essential for satisfactory control.






-16-


Broadcast dusl treatments of 5 pounds of DDT per acre reduce larval
populations to a point where economic damage to most crops would not be
expected for one year, but do not last long enough to protect subsequent
crops. Ten pounds of DDT per acre applied in this manner almost
completely eliminates larval populations and is just about as effective as
heavier applications. Therefore, the 10-pound dosage is used for general
treatment.
DDT applied broadcast as a dust in the fall and immediately disked
into the soil is the most effective treatment yet found for control of white-
:r.-ingc-d beetles. Most of the larvae are small at this time of the year, and
are close to the surface, where they are likely to come in contact with the
insecticide. Moreover, small larvae.are more susceptible than large
larvae to DDT. However, if fall plowing is not practiced, a DDT soil
tr. atnme;t at the time of breaking the land in the spring is preferable to
a fall surface treatment with the DDT not incorporated into the soil until
the following spring.
Ten pounds of DDT broadcast and worked into the soil is much superior
to application in the rows, in the over-all reduction of larval populations.
However, DDT applied in the row at the time of spring planting might give
better protection of the immediate crop, as the insecticide would be con-
centrated in he plant-root area.
Treatment of foliage for control of adults.--Although soil treatments
with DDT are highly effective in controlling larvae, it is evident that not
all infested properties can be treated in this manner. There are vast
acreages of permanent pasture, railroad rights-of-way, and industrial
properties which are infested with white-fringed beetles and constitute a
hazard o, spreading the beetle to uninfested areas. On these lands the
control of adults is necessary, and this can be accomplished best by foliage
applications at the rateof 1/2 to 1 pound of DDT per acre at 2- to 3-week
intervals throughout the adult-beetle emergence season. When immediate
mortalities are desired to reduce the danger of spreading the beetle, a
foliage rather than a soil treatment must be applied. DDT worked into
th-, soil at the time of application results in a surface concentration of
the insecticide which is insufficient for killing adult beetles, and the entire
effect of such treatment is that of a larvicide. In surface applications pro-
visions must be made for safety to livestock.
As a foliage treatrnent DDT may be applied (1) in a suspension, by mix-
ing DDT lust containing a wetting atgent with water (or adding the wetting
agent); (2) in an emulsion, by dissolving technical DDT in a suitable solvent,
adding an emulsifier, and mixing with water; (3) in a solution prepared
by dissolvir.g technical DDT in an auxiliary solvent (as xylene) and further
dilutirng with a cheaper and less soluble solvent (as kerosene), or dissolving
Q.e DDT In a larger quantity of the regular solvent without the auxiliary
7olvent; (4) in a dust diluted with an inert carrier. Methods (1), (2), and (4)
"'also been ti--d in soil tre.:._rrvnts against white-fringed beetle larvae.
DDT emuls'-Jnns and suspens,.oas applied to the foilage during the
emer :'iice season have been very satisfactory against white-fringed
beet1 adults. .V'.ien applied as a dust or as a dilute or concentrated






-17-


spray to foliage on idle or semicultivated land in several one-third
pound per a: re applications, DDT has be-en appreciably more i-.4fective
against -iadults of Gra.honpithu:- leucoloma fecundus ,a. sil
number" of appl-c" ti -f cryc.' '",,- r r ar ir-.te -"I 12 -.'-' -' p
,. -, -.:;-iius T -, reducl':'i f. n su fo +. '".- -tr en resul"
of !iling the adu.ts c: .. ib- b wt larv as .. e e t
Sci-, rather tv!Fr. o 0 ?.' U-silu. ac .- "- *.- v e ir
the soil.
In a nurnoer o, fieic' les. s:.';.- p'.li '-ions of 5 to 1 -
per acre to the foliagcr on idle or :,I CL m '" c. : the -i
emergence season were i.sn-ati,'-. *..ry in f.- : .' .,- t .s",
populations. Where, 5 'oLunds of D'&'r r e acre or 1.,ss '-.*: .4-: to t.
foliage in a season, this amou-_t hd to h.- divided intP at east f e li
cations in order to achieve satisf&acLory larval redInio. In .*-re ral th
larval reduction from a given amount of DDT increase, d with th number
of applications.
Emulsion sprays gave higher m:ttalities of adult beetles iha.r sus-
pensions when- applied as single foliage treatments at 5 or 10 nound-.: c
DDT c-r acre. The superior results were probably d._ie tn the great:
adhesiveness of the emulsion, which allows the DDT residue to rem-i.
longer on the surface of the foliage and scil. Multiple 1-pounri-t.er-acre
applications of emulsion were also superior tc an iJ:tlcal nm_.r
suspension treatments. Emrnulsion sprays applied as a surfac.. trealm--t
on idle land in thE fall of the year at rates up tc 12 pounds of DL'T p-r
acre showed no effect on adults emerging the following sumr-.-r an
indication that the DDT showed no residual action' on the surface fr:
one year to the r..':'.

Ef'.ect of DDT 'r C:-.-

Tess;. conducted to deter in.,L tn e e' .ect o" DiT ?.s soi a. fo'-,..:e
treatmeintF at the dosages -'ver. a'-, c-' showed:' th. ,'-: "-'- :- :.,
on the foliage or vieic were to be 1 r--.,ectec rr-.m whiLe-fri' '- tl
control operations with DDT or., cro.is commonly grcwn in :hK are<- -,
infestation. Emulsion sprays appiied at the rates of 5 ard, 10 r-ou-n(I: -
DDT per acre (with 5 and 10 quarts of xv'ol, respectively) in 6-1/2
allions of spray liquid had no adverse effect on the foliage of r:utte:
oeans, snap beans, cabbage, sugarcane, corn, cotton, cucumber, lettuce,
English peas, field peas, tomatoes, and turnips. Reco,-Js t-kepn on sra,
ben-. and tomatoes indicated no loss in yield. Arn -mu.ion ..,pii.C at
5 ,',u.ios oer acre to a la-ge number of orr.nme',ta' plants a
deL' '.- nal effect on the foliage.
Dt1"c su.--)-nsions applled as s.-'i. tr-:.tr1r.en's at -,4es t. 1 .?* .-
SDI -e .d dver effect on tT-! 'i-_j. of 1b'1. 1. c
-.- - ," ," peas, tr- l,;,. .-' t,:, -r" :--e --es. -.o'ns
su ; -: -. ) : lie .s s,.il treatir..3 '.-, c. r:-.c, s of 5 Ac.d 1C r,.. n :





-18-


DDT per acre had no effect on the yield of snap beans, corn, sweet-
potatoes, peanuts, or tomatoes.
In control operations against the white-fringed beetle DDT is not
applied to crops where the foliage or other exposed portions of the plant
are consumed by man or animals, because of the hazard involved. Studies
have indicated that an appreciable quantity of this insecticide is stored
in the fatty tissues of animals that have fed on treated foliage, and is
also found in the milk, where it was concentrated in the butterfat.

Fumigants

Fumigation is very effective in killing white-fringed beetle larvae
and pup.. in the soil. However, the cost of such treatment is compar-
-'vevly '._ d,-rFd its use is ccrn.r-.7-d to small, isolated infestations.
Sror~~ i ,me nurseries have beeri fumigated with methyl bromide
,.:.:-, i" e, cu -t to the owners a':- not prohibitive.

Biological Cori. rol

'-.- ,ive sear.- n was made in S'tuth America by the Division of
Foreign -arasite Introduction for natural enemies of white-fringed
:-.r-]es in native abitat. In Argentina, Uruguay, Chile, and Brazil
several tho. .-and _]'r,3;-hogriathus leucoloma larvae and adults were
e.d 'r-.-d fr,.s p *,sence of parasites, with entirely negative results.
ar :-- numbers -'f mass-s were exposed in infested fields,
S e we.'- foundto be parasitized. These studies indicated that para-
sites -,o not exert an:, appre' ible control on white-fringed beetles in
S 'uth Amerrica.
Observations over a period of years in the infested portions of the
United States made by the Division of Cereal and Forage Insect Investi-
gations, in which thousands of eggs, larvae, pupae, and adults were
examined, failed to disclose the presence of any insect parasites.
Tachinid eggs were found on a few adults of four species of white-fringed
beetles, but in none was successful parasitism reported. Thousands of
eggs have been exposed in infested fields, but no egg parasites have been
discovered.
Parasitic nematodes of the genus Neoaplectana were found to attack
white-fringed beetle larvae throughout their known range in the United
States. These parasites proved to be a controlling factor in certain
isolated localities in Harrison County, Miss., but were not of economic
importance elsewhere. These nematodes seem to be more numerous
in undisturbed land than in cultivated fields or other areas disturbed
by man-made enterprises. Thus, with few exceptions, the parasite does
not build up sufficient populations in the ecological environment most
suitable for white-fringed beetle development. Other species of parasitic
nemratodes have been found that attack the larvae on occasion, but none
were of any practical consequence.






- 19-


Tic fur,-..i Metarrhiz.ium anisopliae sometimes attacks white-fringed
beetle larv. in '. field, but has not proved to be of economic impor-
tance.
Numerous oredators have been found in the act of destroying white-
fringed beetle adults in the field, but predation is not thought to be an
important factor in controlling beetle populations. Predators observed
attacking these insects included certain insects, spiders, amphibians,
reptiles, birds, and mammals.
Cultural Control
Although the main efforts have been directed towards preventing
further spread of the beetle by applying the necessary regulatory pro-
cedures and suppressing populations with insecticides, a cultural cont uol
program is also in operation. Farmers on infested acreages are en-
couraged to adopt certain cultural practices in order that they may
conduct their business profitably in the presence of the insect.
Since the economic importance of white-fringed beetles is due to the
damage done by the larvae in the spring of the year, the timing of crop
planting is an important factor influencing subsequent plant injury. The
planting of suitable crops is also of importance, since the fecundity of
the adult varies tremendously with the types of food plants consumed.
During the summer months larval populations are negligible, and
during the fall and early winter larvae may be numerous but are usually
too small to cause appreciable e-.unomic damage.
Legumes are favorable food plants for both larvae and adults, and
induce heavy oviposition by the beetles that feed on them. Wherever
possible, farmers on land with high beetle populations are encoui-aged
to grow fibrous-rooted plants, such as oats and other small gri.n 5,
instead of corn intercropped with velvetbeans. They are also urged to
grow the necessary soil-building legumes, such as lupines and Austr .'an
winter peas, in the winter. The oats and winter legumes may be planted
in September and October and therefore escape injury by the larvae.
Furthermore, because of their more extensive root systems, crops
planted in the fall can withstand attack by the larvae the following spring
better than can spring-planted crops.
Other recommended practices include the solid planting of corn
rather than intercropping with legumes; the planting of summer legumes
such as peanuts, velvetbeans, or other primary food plants of the insect
on not more than one-fourth of the cropped land; and the production of
these leguminous crops not more than once in three or four years on the
same land. Permanent pastures are also recommended.
Studies have shown that different soil types in the same area have
varying beetle populations even though identical crops are planted ther,..;n.
Therefore,in an over-all cultural control program farmers are encourag--d
to plant their necessary cash crops, which may be conducive to high
beetle populations, on the portions of their land that by observation -.En.
to be least favorable to build-up of beetle populations.






UNIVERSITY OF FLORIDA


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