RESULTS
 Nearly 7.5 cm of rain fell during the 10-week study. The
average daily temperature was 29*C.

Cantaloupe
 Only 69% of the seeds germinated, and during the following
two weeks 12% died from damping-off (Rhizoctonia suspected).
Powdery mildrew (Erysiphe sp.) developed into a severe problem
by the time the first fruit was approximately 8 cm in diameter.
The mildew first appeared 17-18 days after seedling emergence
and was observed on the underside of most leaves one week later.
One or more fungicide sprays are needed when the first symp-
toms appear, otherwise the basal leaves die and leaf death slowly
progresses distally on the vine until only the distal third or less of
a plant remains green 12 weeks after seedling emergence.

Melonwornis (Pyralidae)
 Eggs of the melonworm, Diaphania hyalinata (L.), first ap-
peared three and a half weeks after seedling emergence and 22%
of the leaves had one or more eggs on them at this time. One
week later 36% of the plants had larvae, 31% of the leaves had
feeding damage and 12% of the leaf surface was eaten (Fig. 1).
By the fifth week after emergence 63% of the plants had melon-
worms, and an average of 3.2 larvae occurred per plant. Larvae
were on 89% of the plants by the sixth week and thereafter all
plants were infested.


 FIG. 1. Melonworm larvae on cantaloupe.


 3 4 5 6 7 8
 Weeks After Seedling Emergence

 By the sixth week the ovipositional rate of the increasing adult
population caused moderate-size plants (35-40 leaves/plant) with
3-5 melonworms to develop economically threatening popula-
tions two weeks later with 43-74 larvae and 20% of the total leaf
surface eaten (leaf number ranged from 83-136/plant). If no in-
secticides were used at this point the plants would be heavily or
completely skeletonized in about three more weeks.
 Only 73% of the field-collected pupae were viable and 49% of
these were parasitized. Seventy percent of the parasitism resulted
from a new species of ichneumon wasp, Agrypon caribbaeum-
Bland. Rearing of this larval parasite for potential biological con-
trol of melonworms is being conducted by the USDA-ARS
Southern Region U.S. Vegetable Laboratory, Charleston, South
Carolina (personal communication, Kent D. Elsey). A. carib-
baeum is described by Bland (1984).

VOL. XX-PROCEEDINGS of the CARIBBEAN FOOD CROPS SOCIETY


 A second ichneumon, Eiphosoma dentator (F.), accounted for
 only 3% of the emerged parasites. It ranges from southern U.S.
 and the West Indies to South America and is common in the
 tropics (Krombein et al., 1979). Most of its hosts are in the
 Pyralidae, subfamily Pyraustinae, but it had not been recorded as
 a melonworm parasite.
 Nearly 15% of the parasites were a chalcid wasp, Brachymeria
 ovata Say, a known pupal parasite of melonworms. It occurs
 throughout most of the U.S. and Mexico and has been recorded
.from the West Indies (Thompson, 1955; Krombein et al., 1979).
 A tachinid fly, Nemorilla pyste Walker formed 12% of the
 parasite complex. It is found in most of North America including
 Mexico and has been recorded as a melonworm parasite (Arnaud,
 1978).


 Leafminer Flies (Agromyzidae)
 The vegetable leafminer, Liriomyza sativae Blanchard, first ap-
peared in cotyledons four days after seedling emergence and, by
the following week when the leaves were open, nearly 50% of the
cotyledon surface was mined. The third week after emergence
when up to three pairs of leaves were open, most of the mines
were on the first pair of leaves and averaged 0.5 mines per leaf.
New miner damage decreased by the fourth week and damage
appeared negligible thereafter.


Aphids (Aphididae)
 Melon aphids, Aphis gossypii Glover, first appeared on the
 ventral leaf surfaces ten days after seedling emergence and the
 population increased rapidly thereafter. The population was
 localized on a few vines at first but spread to all plants by the
 sixth week. No aphid-infested young plants (6-20 leaves) survived
 to bear fruit unless they were sprayed with an insecticide. Leaves
 of young plants with high aphid populations (ca. 40 aphids/16
 cm2 leaf surface) curled downward and the plants became
 stunted. Aphid control is needed before leaf curling begins.
 Older plants (with more than 85 leaves) with moderate to high
 infestation grew poorly. Complete spray coverage of a leafs ven-
 tral surface is important for effective control, but this can be dif-
 ficult to accomplish due to the horizontal position of leaves and
 their proximity to the ground.
 Aphidophagous syrphid larvae, Pseudodoros clavatus F., first
 appeared four weeks after seedling emergence (two weeks after
 aphids were first recorded). However, the syrphid population in-
 creased at a slow rate and occasional clusters of 3-5 larvae/leaf
 were not observed until nearly ten weeks had passed and signifi-
 cant aphid damage had occurred. Even at this time the syrphid
 population was too low (1 larva/42 leaves) to exert sufficient con-
 trol of the high aphid population.
 Lacewing larvae, Chrysopa sp., were occasionally observed after
 the ninth week, but their population never exceeded 1 larva/85
 leaves. Lady beetle larvae, Cycloneda sanguinea Casey, were less
 common and averaged 1 larva/428 leaves.



 Ants (Formicidae)
 Workers of the fire ant, Solenopsis geminata F., were first
 observed on plants four days after seedling emergence and the
 ant population increased parallel with the aphid population.
 Plants with the highest aphid populations generally had large
 numbers of ants tending the aphids. It was not uncommon to
 find a leaf with 400 aphids and 75 ants. Occasionally ants were
 observed transporting aphids. On young plants (6-20 leaves) ants
 frequently covered part to nearly all of the basal leaves with soil
 while they tended the aphids. Ant control would probably reduce
 aphid dispersal and increase their susceptibility to parasites.


57