PARASITES HIBERNATING IN BROWN-TAIL WEBS. 
287 
There were plenty of caterpillars of the brown-tail moth available 
and the smallest that could be found were confined in a cage with the 
first of the parasites that were reared. Oviposition was not observed, 
and the parent adults did not live very long, but the caterpillars did 
very well for about 10 days, after which the cocoons of Meteorus 
began to be found in the cages in most gratifying numbers. It 
seemed as though success was assured, and other similar experiments 
were immediately begun in the hope that some method would be 
found for prolonging the life of the adult parasites in confinement 
and securing more abundant reproduction. 
'\ he days of rejoicing over tliis, the first successful reproduction 
experiment with any of the parasites imported in 1 1)07, were very few. 
In about a week the adults began to issue from the cocoons, and 
all proved to be males. It 
Looked like a curious coinci- 
dence at first, but when one 
after another of the various lots 
of cocoons hatched and out of 
the total of every single 
individual was of the one sex, 
it was evident that something 
serious was the matter. Where 
the trouble lay was not ascer- 
tained at that time, nor has it 
been determined as the result 
of Other experiments similarly 
conducted in later years. In 
all, 24 1 adult Meteorus have 
been reared in confinement , and 
among them there have been 
just 5 females, not one of which 
was secured until the late sum- 
mer of L908. Breeding Meteorus on a Large scale for colonization 
purposes under circumstances like these can not be considered as an 
economically profitable venture. 
The numbers of Meteorus reared from the caterpillars imported in 
the hibernating nests were increased by the addition of some few more 
secured from importations of full-fed and pupating caterpillars later 
in the season, and a small colony was planted in 1907, but it was so 
small as to make its success more than doubtful, and it was deter- 
mined to rear enough for at least one good colony in the spring of 
1<)08. 
A description has already been given of the methods winch were 
perfected during the winter of 1907-8 for the rearing of Apanteles 
lacteicolor Vier. in large numbers from the caterpillars of the brown- 
Fig. lis.— Mc!(orus versicolor: Adult female and co- 
coons. Much enlarged. (Original.) 
