PAKASITES 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. 



The days of rejoicing over this, the first successful reproduction 

 experiment with any of the parasites imported in 1907, 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 156 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, 244 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 1908. 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 sprint of 

 1908. 



A description has already been given of the methods which 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. 68. — Meteorus versicolor: Adult female and co- 

 coons. Much enlarged. (Original.) 



