EGG PARASITES OF THE GIPSY MOTH. 177 



tion annually, and its seasonal history is closely correlated with that 

 of its host. Schedius, on the contrary, will pass through a generation 

 per month, so long as the temperature is sufficiently high, and its 

 seasonal history is in no way correlated to that of the gipsy moth. 

 It appears not to hibernate in the gipsy-moth eggs, and it is quite 

 probable that an alternate host is necessary to carry it through the 

 summer months after the gipsy-moth eggs have hatched in the spring, 

 and before the moths begin depositing eggs for a new generation. 



At the time when the popular account of the parasite-introduction 

 work was prepared for publication through the office of the Massa- 

 chusetts State Forester it was considered to be much the more 

 promising of the egg parasites, and its history in America was spoken 

 of as one "of the most satisfactory episodes in the work of parasite 

 introduction." The account of the first successful importation of 

 living specimens as given at that time is included in the two follow- 

 ing paragraphs, which are quoted verbatim. 



As long ago as the spring of 1907 a few dead adults were secured in an importation 

 of gipsy-moth egg masses received during the winter from Japan, but none was living 

 on receipt. During the winter next following, large importations were made, and 

 many thousands of eggs, from which some parasite had emerged, were found, but not 

 a single living specimen was obtained. It was evident that it completed its trans- 

 formations and issued in the fall, and that, if it hibernated in the eggs, it was warmed 

 to activity while the packages were in transit to America, and the adult parasites 

 either died or escaped en route. 



In the fall, winter, and spring of 1908-9 a large quantity of eggs of the gipsy moth 

 were received from Japan, the shipments beginning early in the fall and continuing 

 until nearly time for the caterpillars to hatch in the spring. The first, received in Sep- 

 tember, contained hundreds, possibly thousands, of the parasites, which had issued 

 from the eggs en route, and all of which, as usual, had died; not a single living individ- 

 ual was received. Specimens were referred to Dr. Howard, who found that they 

 represented an entirely new and hitherto undescribed species, which he named after 

 Prof. Kuwana, who collected and sent the eggs from which they had issued. A single 

 pair of living specimens rewarded the careful attention which was lavished upon the 

 importations received later in the fall and during the winter, and it was not until 

 April, 1909, that a mated pair could be secured. During that month a total of 11 

 individuals issued from cages containing Japanese eggs recently received. 



These 11 individuals served as the progenitors of a numerous and 

 prolific race, but the story of the investigations which were made 

 upon the various shipments of egg masses received at the laboratory 

 from September, 1908, to April, 1909, which was not touched upon 

 in an earlier account, is perhaps worthy of a place here. 



LIFE OF SCHEDIUS AND ITS RELATIONS TO OTHER EGG PARASITES, PRIMARY AND 



SECONDARY. 



Mention has already been made of the rearing of a small encyrtid 

 parasite from Japanese eggs in company with Anastatus in the sum- 

 mer of 1908, of the doubts which were felt as to its true character, 



95677°— Bull. 91—11 12 



