262 
PARASITES OF GTPSY AND BROWN-TAIL MOTHS. 
parasites known to hibernate within them are believed to be thor- 
oughly well-established in America, their importation has been dis- 
continued. 
These parasites, including two which are secondary, number eight 
species in all, and will be first considered as a group. In the subse- 
quent pages each will be taken up separately, and the story of its 
importation and progress in America will be told. The species are as 
follows : 
Monodontomerus sevens Walk. Adult females hibernate within 
the nests, but do not attack the caterpillars. 
Pteromalus egregius Forst. Females enter the nest in the fall 
and oviposit upon the caterpillars after they have become dormant. 
Their eggs are deposited, and the larvae feed externally (fig. 59), be- 
coming full fed before cold weather puts a stop to their activity. 
Transformations are completed in the spring, and adults of the new 
generation leave the nosts about two or three weeks following resump- 
tion of activity on the 
part of the caterpillars. 
Apanteles lacteicolor 
Vier. Attack is presum- 
ably made upon the very 
small active caterpillars 
in the fall before they 
enter the nests for the 
winter. The parasitized 
caterpillars hibernate 
and resume activity in 
the spring. About the 
time when, had they re- 
mained health}", they 
would have molted for 
the first time, they die, 
and the parasite larva soon issues and spins a white cocoon within 
the molting web, which may or may not be upon the winter nests. 
There is no second generation upon the caterpillars of the brown- 
tail moth the same season. 
Meteorus versicolor Wesm. Habits essentially the same as those 
of Apanteles until after the caterpillars have resumed activity in the 
spring. The parasitized individuals usually live to molt once, and 
are overcome and destroyed away from the molting web or nests. 
The cocoons, which are characteristic of the genus, swing from the 
end of long threads. The adults issuing from them immediately 
attack the larger caterpillars of the brown-tail moth for a second 
generation. 
Zygobotkria nidicola Towns. Hibernating habits similar to those 
of Apanteles and Meteorus. The" affected caterpillars become full 
grown and spin for pupation before being overcome by their parasite. 
Sometimes they pupate. The parasite adult issues at about the time 
when the moth would have issued had the caterpillar completed its 
t ransformat ions. There is but one generation annually, and no alter- 
nate host is necessary. 
Fig. 59.— Larvae of Pteromalus egregius feeding on hibernating 
caterpillars of the brown-tail moth. Much enlarged. (Origi- 
nal.) 
