606 MISC. PUBLICATION 657, U. S. DEPT. OF AGRICULTURE 
the species of parasites recovered from Phyllotoma. Dowden (139) 
gave an account of its life history. The adult is a delicate insect about 
1% inch long, and black, except for its yellowish legs. The female 
lays an external egg in the host larva’s mine, and the tiny parasite 
larva makes its way to its host, where it feeds externally. Develop- 
ment is rapid and only 8 to 10 days are required for the larva to com- 
plete feeding and spin its tough cigar-shaped cocoon inside the host 
larva’s mine. There is only one veneration a year, and the winter is 
spent in the cocoon stage. Pupation takes place in the spring, and 
adults emerge early in the summer. 
A panteles congregatus (Say) is a very general parasite of sphingid 
larvae, but has not been 
recorded from other fam- 
ilies of Lepidoptera. It 
is an important parasite 
of the catalpa sphinx 
(Ceratomia catalpae) 
as well as the tomato 
hornworm (Protoparce 
quinquemaculata), the 
tobacco hornworm (P. 
sexta), and many others. 
At times the catalpa 
sphinx is injurious 
throughout the Eastern 
States, and A. congrega- 
tus is almost invariably 
- found associated with it. 
Figure 185.—Larvae of the catalpa sphinx bear- (Gilmore (/S0@) studied its 
ing coccoons of Apanteles congregatus. biology as a parasite of 
the tobacco hornworm. 
The adult is a small, black insect, having yellowish legs, except the 
coxae which are black. It isa little less than 1g inch long. The adult 
female usually oviposits in the posterior segments of second- and third- 
instar host larvae. The act of oviposition requires from 20 to 30 
seconds, and a number of eggs are laid during one insertion of the 
ovipositor. The parasite larvae float freely in the lumen of the host. 
Development is completed in about 10 days. At the end of this time 
each parasite larva cuts its way through the host larval skin and spins 
a small white cocoon on the outside. Two hundred or more such 
cocoons have been seen on the body of one caterpillar (fig. 185). An 
average of 112 cocoons were formed on 12 larvae of Protoparce sexta 
under. laboratory conditions. During the summer about a week is 
spent in the prepupal and pupal stages, ~and from two to several genera- 
tions may be completed in a season. The winter is spent in the cocoon 
and, since the cocoons are loosely attached to the host larvae, they 
usually fall to the ground, where they are partly protected by debris. 
Adults emerge early in the spring. 
Bassus pumilus (Ratz.),a parasite of the larch casebearer (Co/e- 
ophora laricella), was successfully introduced into the United States 
from Europe in 1931-86. Recoveries have been made in Maine, New 
Hampshire, Vermont, and Michigan. In Europe it was found to be 
an important parasite of the c asebearer in Austria and Holland. Col- 
lections made in England showed it to be present, but of negligible 
