MIMEO REPORT EV-1972-2
on the Florida East Coas
JUN 2 9 1972
^ I.F.A.S. Univ. of Florida
W. G. Genung and H. Y. Ozaki
I.F.A.S. Agricultural Research and Education Center, Belle Glade
Agricultural Research Center Fort Pierce
AREC9 BELLE GLADE
Belle Glade AREC iimeo Report EV-1972-2
The Pepper Weevil Anthonomus eugenii Cano
on the Lower Florida East Coast/
'!illiam G. Genung-2
Henry Y. Czaki2
Pepper growers in the counties of Palm Beach, Broward and martin should be
alert to another pepper pest. The pepper weevil Anthonomus eugenii Cano has been
found at widely separated points in the area. This weevil is a native of Mexico
from whence it has been accidentally introduced, directly or indirectly, into
Texas, California, New Mexico, Arizona and Florida. Infestations that started in
New Jersey and Georgia apparently died out because of low temperatures, Boswell
et al. (1964). The species became established in lianatee County Florida in 1935
and subsequently spread to adjacent Gulf Coast counties. The weevil was unknown
on the lower east coast, however, until its occurrence there during the 1971-72
THE EAST COAST INFESTATION
In mid-MIarch a specimen of a weevil was found in a pepper pod from unsprayed
plots on the ilorlkami Farm, Delray Beach, and sent to AREC, Belle Glade for identi-
fication. Although badly damaged the specimen was recognized as a weevil and in
all probability the pepper weevil. Inspections were made in the Delray Boynton
area along Carter Road and Hagen Ranch Road and virtually 100% infestation in
dropped fruit was found to occur there. Infestation was also noted in pods taken
from the plants. He next inspected large commercial plantings in the Jupiter
area and northwest of the Indian Trial Ranch. Infestation at the Indian Trail
Ranch was about 25% and in the Jupiter area, near the Martin County line, the
infestation in two plantings visited was about 2% in one planting and 0% in the
other in dropped fruit. On March 24, 1972 our identification of the species was
confirmed by Dr. R. E. VWoodruff, Division of Plant Industry, Florida Department of
It appeared from the northward decline in infestation percentage figures that
the dispersion of the insect was from south to north since normally lighter
numbers would occur toward the periphery of infestation. We next scouted southward
into Broward County. The only pepper plantings located there were small commercial
2/ Professor (Entomologist) and Associate Professor (Associate Horticulturist)
AREC, Belle Glade and ARC, Fort Pierce, respectively, University of Florida
Institute of Food and Agricultural Sciences.
plantings in the northern section near the Palm Beach County line and south of
Hillsborough Road. A sample of 49 dropped pods was 100% infested.
In questioning growers about appearance of the weevil on their farms, it
was found that most had not noticed the beetle or were unaware that a pepper
weevil existed. Others claimed to have noticed the weevil or its damage for
varying periods of from several months to a year. It is interesting to note that
of many hundreds of peppers opened from sprayed plots during the winter at the
ARC, Fort Pierce, experimental farm on Carter Road west of Delray Beach, no
weevil infested peppers were noted until Harch 1972. Figures 7 and 8 show the
known national, state and local distribution of the pepper weevil.
The pepper weevil damages peppers by: 1) feeding and oviposition punctures
of adults in the young pods and bloom, 2) causing excessive dropping of the
pods, and 3) by presence of larvae and pupae in the fruit which causes discolora-
tion and renders them unfit for human consumption. Typical damage to individual
fruits are shown in figures 5 and 6.
Elmore and Campbell (1954), Goff and Wilson (1937) and Boswell et al. (1964)
all considered the pepper weevil among the most important pests of this crop.
Our observations to date are in agreement with this assessment. Goff and Wilson
(1937) reported whole plantings destroyed by the weevils in the Bradenton area
during the 1930's. Similar accounts are given by Elmore et al. (1934) for the
western pepper producing areas.
DESCRIPTION OF STAGES
Adult weevil: The pepper weevil looks like a small caliber cotton boll
weevil, to which it is in fact generically related. It is clothed with yellowish
brown to grayish hairs, over a dark brown body and wing covers. The hairs on
the wing covers often get worn off giving a patchy appearance. The chewing
mouth parts (mandibles) are on the end of the long, curved snout. The "elbowed"
antennae are inserted about 2/3 the way down.the snout. The weevils are from
about 2-3/4 mm to 3-1/4 mm in length (25.33 mm = 1 inch). Like other members of
the genus Anthonomus the legs bear prominent spines on the femurs, (see cover).
Egg: The egg is broadly oval in outline, pale when laid, but becoming
yellowish with age.
Larva: The grub when mature is about 12 mm long, comparatively stout, leg-
less and usually observed in a C shaped outline. It is usually a dirty white
hue with a yellowish tan head and brown jaws, Figs. 2 and 3.
Pupa: The pupa is about the size of an adult. The legs, snout and other
adult appendages become evident in this stage, Figs. 2 and 4.
Pre-emergent adult: The newly transformed adult is light brown in color
and remains in the pod until sufficiently hardened to chew its way from the pod.
Mating: Young adults held at about 75-80 F mated about 2-3 days after
Oviposition: Egg laying occurred 4 to 5 days after emergence. Eggs were
deposited in young sweet peppers.provided for the purpose. A few eggs were
deposited on the outside of the pods. Goff and Wilson (1937) reported that eggs
of unfertilized females were deposited on the surface of pods but that normal
oviposition occurred after maing. In this study 3 eggs that were laid on the
surface were placed in holes artificially prepared. These three eggs hatched in-
dicating that fertilized females may also occasionally lay eggs on the pod surface.
Normally the female gnaws a hole into the pod to about the depth of the snout,
and then turns and inserts her ovipositor and deposits an egg. About 5 to 10
minutes or more are required to form this hole. After egg deposition the hole is
sealed by filling with a brownish fluid that hardens and effectively plugs the
opening. Limited observations indicated that females averaged nearly six eggs
per day. Since these females were among pairs confined together individual
variations in this regard were not obtained.
Incubation: The time required for egg hatching at about 75-80F was between
3 and 4 days and averaged 3.29 days during late March and April. This appears to
be in line with the 2.5 to 3.0 days recorded by Goff and Wilson (1937) during
Larval stage: The larval period in this study ranged from 6 to 10 days.
After hatching the minute larvae chew their way into the core area in young pods
where they feed on the seed and core. Where eggs are laid in older pods the
entire development sometimes occurs in the wall of the fruit. Before pupation
the matured larva forms a cell-like space in which transformation to the pupa
Pupal stage: The pupal stage required 4 to 5 days.
Pre-emergent adult: The young adult remains in the pod until sufficiently
hardened to chew through the wall of the pepper.
Total time from egg to adult required 16 to 19 days and averaged about 17.5
days. Goff and Wilson found about 13 to 16 days during June. During the cooler
months of a normal year development would undoubtedly be more prolonged than
reported either here or by Goff and Wilson (1937). Time required for development
of stages to adult are given in Table 1.
Host plants: While peppers including both hot and sweet varieties are
definitely the preferred hosts of this weevil, it is known to attack eggplant
(Boswell et al. 1964, and Goff and Wilson 1937). It has attacked nightshade in
California but Goff and Wilson (9.37) were unable to find either larvae in berries
or adults on the plants of nightshade in the Florida gulf coast area. Further-
more these authors found that adults confined with the nightshade in cages would
not oviposit therein although they resumed oviposition when peppers were provided.
In this study the writers found the adults on nightshade plants and during a
period of about 45 minutes examination 4 pepper weevil larvae were found in night-
shade berries in the Delray Beach area.
Temperature: The literature indicates that this naturally tropical weevil
is highly susceptible to low temperatures (Boswell et al, 1964, Elmore and
Campbell, 1954). It would, therefore, be much less of a problem during cold or
even normally cool winters. Its scarcity (or absence ) in the Florida gulf
coast area in recent years may be due to several severe winters including 1957-
58 and 1964-65. However, the last Division of Plant Industry, Florida Department
of Agriculture, record for that area ante-dates those winters by about 12 and 20
years respectively. Elmore et al (1954) credit fluctuating yearly temperatures
with the advance and recession of this weevil in California and elsewhere.
Natural enemies: Elmore and Campbell (1954) concluded that natural enemies
in California were of little importance, particularly because of the inaccessi-
bility of the immature stages. Natural enemies also appear to be of relatively
little importance in Florida. We have seen a small jumping spider, probably an
immature Phidippus audax (Hentz), with what appeared to be one of these weevils;
however, the specimens were not secured. Weevils of various kinds including
many small species were found in 59% of meadowlark Sturnella magna argutula
Bangs stomachs at the AREC, Belle Glade. Since many meadowlarks were observed
in pepper plantings it is presumed the apparent fondness for weevils would be
reflected in their diet in pepper fields.
Varietal differences: Three pepper varieties at the Fort Pierce ARC,
Morikami Farm, Delray Beach, were observed for possible pepper weevil resistance
but little could be detected. It was observed earlier that Avelar variety perhaps
was less desirable to the weevils. If any real difference existed, however,
it was merely a preferential factor that became inundated and broke down under
extreme population pressure (Table 2).
Dispersion: The pepper weevil flies readily which could be an important
factor in its rapid spread in the southeastern coastal areas. It can obviously
be spread through the channels of commerce through infested fruit and plants.
For many years DDT was the preferred insecticide for pepper weevil (Boswell
et al, 1964, Brogdon et al., 1967, Elmore et al, 1954). With the abandonment of
this material, toxaphene became the preferred material. As shown by Elmore
and Campbell (1954) many insecticides give good initial control of pepper weevil.
Our tests including standard and experimental materials also indicate that most
insecticides including various chlorinated, phosphatic and carbamate materials
give good initial control. The problem of insecticidal control, as various
authors have noted, is complicated by the habits of the insect and control may.
break down unless a long residual material is used or close interval applications
are made. The immature weevils are relatively safe inside the pods and adults
that emerge shortly after application are likely to survive long enough to
produce eggs in their turn.
Also, sources outside the immediate planting may complicate the situation.
Weevils from untreated, inadequately treated or abandoned plantings can move into
the field. In addition, now that we know the weevils breed in nightshade in the
east coast area this weed must be considered as a source of the weevils.
Results from two randomized complete block experiments superimposed on older
experimental plantings shown in tables 3 and 4 indicated good kill of weevils
present on the Port Pierce ARC, Morikami Farm at Delray Beach. A third test is
currently underway including some materials in addition to those reported here.
Since.this test is on younger plants it is hoped that more residual control data
as well as yield records can be secured therefrom.
It is our opinion that if the current heavy infestation persists, under favor-
able environmental conditions for the weevil that a sanitary program by which
all drops are gathered and destroyed should accompany an insecticide control
program. In addition all nightshade in or around pepper plantings should be
destroyed. While Lannate and toxaphene gave good initial weevil kill during our
tests (Table 3), variety trials under a weekly insecticide schedule of Lannate
and Lannate + toxaphene applications became quite heavily infested. There were
an excessive number of drops in these plots; however, the pods on the plants were
generally considerable' lower in infestation under the insecticide program than in
untreated closely adjacent plantings. The point should again be emphasized that
under saturation population pressure a chemical control program alone may not be
Since all approved materials in our tests gave adequate kill of the weevils
present at application (Tables 3 and 4), we would suggest one of these be in-
cluded in the pepper insecticidal program.
The pepper weevil is a serious pest of peppers as demonstrated by damage
inflicted in California, Texas, Florida, New Mexico and Arizona. Fortunately,
it is hampered to some extent by environmental factors, particularly low temp-
eratures which have caused elimination of the beetle in New Jersey and Georgia
(Boswell et al., 1964), and lattitudinal recessions at various times in California
and Texas (Elmore and Campbell, 1954). Cold winters at various times may have
effected its elimination in the gulf coast (Bradenton Tampa) area of Florida
where it caused severe damage in the 1930's and 40's. Division of Plant Industry
records extend only to 1945. Dr. S. R. Poe (personal communication) has not seen
the weevil in that area nor heard ofl1ny infestations during his tenure as
entomologist of the AREC, Bradenton.-
Our finding that the weevil on the east coast breeds in nightshade, although
Goff and Wilson (1937) could not induce infestation in nightshade at Bradenton
even under duress, might indicate two distinct biotypes of the weevil. This
strengthens our contention that the east coast infestation is independent of the
previous infestations and that the current outbreak originated from infested
peppers from Mexico.
I/ Just before release time for this report, however, it was learned from
Dr. Poe that he had found three pepper weevils in the Immokalee area
The fact that nightshade is a host, even though possibly a poor host, could
complicate control and make either planned or natural eradication more difficult.
There also are other wild species of the genus Solanum in Florida, some with
red and orange berries, that we have not examined for weevils up to this point.
The relatively tough skin of the horsenettle Solanum carolinense might render
these relatively large berries unacceptable to the weevils, but again this has
not yet been checked.
A weekly insecticidal program accompanied by such sanitary practices as
clean up of crop refuse and culls, immediate disking of abandoned plantings,
destruction of dropped fruit and a sound weed control program could result in
virtually weevil free peppers. An insecticidal program alone, under saturation
population conditions, would be at best only partially effective. It is not
beyond the realm of possibility that the proposed program with an occasional
colder than normal winter could eventually result in eradication of the weevil.
To accomplish this, however, the practice of dumping cull peppers from
foreign importations in pastures and other sites from which pepper weevils
could spread would definitely have to be abandoned.
The writers wish to thank Division of Plant Industry Entomologists
Mr. H. A. Denmark and Dr. R. E. Woodruff for furnishing occurrence records on
the older pepper weevil infestation in the Bradenton Tampa area.
Table 1. Duration in days of stages of
humidity of 60-85 percent!/.
pepper weevil at 75-80 F and relative
Spec. No. Egg Larva Pupa Total egg to adult
8 3.5 9.5 5 18
9 3 8 5 16
3 died (unknown cause)
_/ Individuals above the broken line were examined twice daily for progress
of development which was computed to nearest half day. Those below the
line were closely estimated but frequency of examination was reduced to
avoid injury to the insects after incubation.
Table 2. Percent pepper weevil infestation in sweet pepper varieties, Winsberg
Farms, Delray Beach, Florida-- .
2/ I II III IV Avg.
Early Cal. Wonder
1 Dropped fruit, 4/7/72 and 4/13/72.
2/ Total number of infested peppers 17, 171, 163 for the respective varieties,
per 400 foot/row. Later avelar produced 2-6 times more pounds of non-
infested pods than that produced by 23-1-7.
3/ No fruit, early Cal Wonder produced almost no pods because of severe virus
infection. Some pods from early Cal may have dropped from adjacent plots
Line 23-1-7 produced only a few pods because of virus.
Table 3. Number of pepper weevilspeaten from 10 pepper plants per plot 24 hours,
5 days after application- .
Average number of weevils
Treatment Form. A/I/A 24 hrs. 5 days
Carbaryl2- 1I 1.5 0 0.66
Lannate- S 0.5 0 1.00
Thiodan- E 0.5 0 0
Toxaphene-- E 1.0 0.33 0
Phosvel E 1.0 0.33 1.00
Orthene 0.5 0.33 0
Fundal 1 0.5 2.33 1.33
Check No treatment 9.66 5.66
/ Treatments replicated 3 times.
1iaterial approved for use on peppers.
Table 4. Number peppei/weevils counted on 20 plants per plot 48 hours after
Treatment Form. A/I/A Avg. number weevils
Phosvel E 1.0 0
Orthene W 0.5 0
Fundal 1 0.5 0.33
Check No treatment 4.66
/ Treatments replicated 3 times.
Boswell, Victor R., S. P. Doolittle, Leon ,i. Pultz, A. L. Taylor, L. L. Danielson
and Roy E. Campbell. 1964. pepper production. USDA, Agr. Res. Service,
Agr. Info. Bul. 276.
Brogdon, J. E., M. E. Marvel and R. S. Mullin. 1967. Commercial vegetable
insect and disease control guide. Fla. Coop. Extension Service, Univ. of
Fla. IFAS, Circular 193F.
Elmore, John C. and Roy E. Campbell. 1954. Control of the pepper weevil. J.
Econ. Entomol. 47(6): 1141-1143.
Elmore, John C., A. C. Davis and Roy E. Campbell. 1934. The pepper weevil
USDA Tech. Bull. 447.
Goff, C. C. and J. W. Wilson. 1937. The pepper weevil. Fla. Agr. Exp. Sta.
._ II I ILC
Fig. 1 Adults of the pepper weevil
with millimeter scale
Fig. 2 Last stage larvae and
pupae of the pepper weevil
Fig. 3 Larva inside the pepper pod
Fig. 4 Pupa and pupal cell inside
Fig. 5 Peppers attacked by pepper
Fig. 6 Peppers showing typical
interiors as damaged by feeding of
pepper weevil larvae
R SANG SEMINOILE
E HIGHLANDS OKEECHOBE
LRLOTTE GLADES A
Fig. 7- Pepper weevil infestation in U.S. and Florida:
circles show infested states, solid squares older Florida
infestations, solid dots show recent Florida infestations.
Hagen Ranch rd.
Ranch 25 %
West of Jupiter
Fig. 8- Known pepper weevil infestations on lower east
coast, March 1972.