172 PARASITES OF GIPSY AND BROWN-TAIL MOTHS. 



removed from host egg is well represented by figure 14, and the 

 pupa by figure 15. This latter is very beautifully colored, the 

 creamy ground color being set off by darker abdominal bands and 

 wing covers, and by the delicately tinted reddish eyes. 



It was soon demonstrated by a careful study of the European 

 eggs that no other parasite and no secondaries were present. These 

 eggs were therefore kept in confinement until after the caterpillars 

 had all hatched in the spring. Then those which remained were 

 examined, and the number which contained parasites carefully esti- 

 mated, and found to be about 80,000, nearly all of which were con- 

 tained in a very large shipment received during the winter through 

 Prof. Jablonowski, and collected from various Hungarian localities. 



The Japanese eggs, which contained numerous secondary parasites 

 as well as Anastatus, were all carefully rubbed clear of their hairy 

 covering, and those which contained Anastatus larvae (PL XI, Rg. 2) 

 carefully and painstakingly picked out by hand, one by one. In 

 this manner enough to make a total of nearly 90,000 of the para- 

 sites were secured. 



One exceedingly important characteristic of the parasite was not 

 considered with sufficient attention at a time when this might 

 have been done. Several observations upon the activities of the 

 females in the summer of 1908 had led the observer to question their 

 ability to fly; but when several of them were placed upon a large 

 sheet of paper and stirred into action, they disappeared with suffi- 

 cient celerity to banish any doubts which may have been entertained. 

 In considering these crude experiments in retrospect and in the light 

 of subsequent developments, it would appear that their jumping 

 abilities were rather underestimated, because it is now certain that 

 they are either unwilling or else, like the female of their host, are 

 unable to fly. 



A most careful examination of egg masses in the vicinity of the 

 locality where the colony of about 500 had been liberated the summer 

 before had failed to discover the presence of parasitized eggs. It is 

 now known that this was. due to the accident of placing this colony 

 in a locality where the gipsy-moth a wilt" disease proved later to be 

 so destructive as to kill all the pupae which were present when the 

 first of the parasites were liberated, and which it was then thought 

 would produce moths enough to deposit a sufficiency of eggs for 

 attack. As a result of this extreme percentage of pupal mortality, 

 there were practically no eggs within a radius of several hundred 

 feet. 



The cause of failure not being apparent, it was guessed that it 

 might be due to the extremely rapid rate of- dispersion rather than to 

 the reverse, and to provide against loss through too rapid dispersion 

 at first, very large colonies were decided upon as most advisable. 



