Recognizing the Good Bugs in Cotton - Texas Is Cotton Country ...

Microplitis
croceipes
Family: Braconidae
Characteristics: Adults are large dark brown
to black wasps about 1/3 inch long. The
abdomen and legs are yellow to red and the
wings are dark. The cocoons are off white
to yellowish and smooth with long ridges.
M. croceipes is found throughout the Cotton
Belt except it is not reported from
California.
Hosts: In some areas, M. croceipes is one of
the most common parasites of bollworm larvae
in cotton. As many as 50 percent of
bollworm larvae may be parasitized by this
wasp. All stages of larvae are attacked but
3rd and 4th instars are preferred. Budworm
larvae are also parasitized. M. croceipes parasitizes
bollworms infesting alfalfa,
sorghum, tomato, wild hosts and corn in
the whorl stage but not in the ear stage.
General Biology: The adult female stings
the bollworm larva and deposits her eggs
inside the caterpillar. Third instar larvae are
most commonly parasitized. Larger larvae
often drive off the parasite before it can
sting. The wasp’s egg hatches into a grub
which feeds inside the bollworm for about 8
days. The parasitized bollworm soon stops
feeding. Once full grown, the wasp grub
bores out of the dead bollworm and spins a
white cocoon. The adult wasp emerges from
the cocoon in about a week. Development
from egg to adult requires about 15 days at
86°F. There are 3 or 4 generations per year
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