178 PARASITES OF GIPSY AND BROWN-TAIL MOTHS. 



and of the resolve to investigate the matter thoroughly when the 

 opportunity should arise. In accordance with this resolve an inten- 

 sive study of the Japanese importations was begun in December, 

 1908. A large number of egg masses, which showed by the exit 

 holes (of Schedius) that they had been freely attacked by some para- 

 site which had issued in the fall, were selected, then "sifted," and 

 the eggs from each mass were then carefully examined and sorted 

 into three lots, composed, respectively, of the healthy eggs, the eggs 

 from which parasites had issued, and the eggs which were neither 

 one nor the other. Those falling in this third division were scrutin- 

 ized again with still more care. Anastatus was quickly recognized, 

 in most instances, and eggs containing its larvae placed aside. In 

 the majority of the remainder there was evidently no life, but in 

 a considerable number minute, white larvae could more or less 

 plainly be seen, surrounded and more than half concealed by the 

 remains of the embryonic caterpillars which had been destroyed. 

 These eggs were isolated in small vials, in order that there could be 

 no question concerning the identity of the particular host egg from 

 which any particular parasite issued. 



Long before this work was completed the necessity for all the care 

 that was being expended to secure accurate results was made mani- 

 fest by the emergence of no less than three species of parasites from 

 isolated or partially isolated eggs. The first of these to appear was a 

 species of Pachyneuron ( determined by the senior author as P. gifuen- 

 mAshm.), and on account of known habits of other members of the 

 genus was placed as probably secondary. Nevertheless it was given 

 an opportunity to prove itself a primary if it would, and the speci- 

 mens as they issued were confined in vials with gipsy-moth eggs, 

 some of which contained the healthy caterpillars, while others har- 

 bored the larvae of Anastatus. The Pachyneuron paid not the slightest 

 attention to either, but invariably died without attempting ovipo- 

 sition. 



The next species to issue was Tyndarichus navse How., and it was 

 with considerable surprise that it was recognized as different from 

 Schedius. On account of the strong superficial resemblance between 

 the two it had been supposed up to that time that they were one 

 and the same. 



The third was Perissopterus javensis How., of which a single speci- 

 men only was reared. To date this record is unique, and the species 

 has previously been reared only from scale insects. 



There was other and pressing work to be done with the parasites 

 of the hibernating brown-tail caterpillars, and a realization of the 

 difficulties which were likely to attend the prosecution of the egg- 

 parasite investigations, thus complicated by the discovery that &ve 

 and possibly more parasites were involved of which only one was 



