1909.] PUBLIC DOCUMENT — No. 73. 73 



Gypsy moth laxvsB and pupae, about 161,000. 



Gypsy moth larvae from Japan, 8 large boxes, containing several 

 thousand larvae and parasite cocoons. 



Predatory beetles, 2,892. 



It -win be noticed that only about half as many of the hibernating 

 nests of the brown-tail moth were imported during the winter of 1907- 

 08 as during the winter of 1906-07; but the smaUer number is offset by 

 the larger numbers of larvae, pupae and egg masses, so that the gross 

 amount received is about the same as that of the previous year. The ■ 

 material received from Japan listed above came in before July 1, but 

 in all there have been received about 40 boxes, nearly all of large size. 

 From one shipment of the cocoons between 40,000 and 50,000 adults 

 of one of the most important parasites of the genus Glyptapanteles 

 were reared and were liberated directly in the open. 



The colonization work has been going on rapidly during the summer, 

 of 1908, and of the species colonized the following have been the most 

 numerous : — 



Pteromalus from the brown-tail moth nests, .... 114,000 



Trichogramma from the brown-tail moth eggs, . . . 11,600 



Telenomus from brown-tail moth eggs, 4,560 



Apanteles of the brown-tail moth, 12,875 



Japanese Glyptapanteles, 45,000 



Meteorus from brown-tail moth, 1,080 



PwpZo.from brown-tail moth pupae, 2,051 



Unclassified Ta«hinids, 4,177 



Named Tachinids, 1,600 



Cdlosoma sycophanta, adults and larvae, 978 



thus making nearly 200,000 of the most active enemies of the gypsy 

 moth and brown-tail moth liberated under the most favorable conditions 

 during the year. 



The results of the colonization work of previous years have not be- 

 come very evident. It is altogether likely that the species introduced 

 have found conditions favorable to their increase, and that at the pres- 

 ent time they exist in considerable numbers. The area, however, is so 

 extensive as to make their occurrence in ordinary collections a matter of 

 chance rather than of likelihood. There have been during the past two 

 years a tremendous destruction of the larvae of both brown-tail moth 

 and gypsy moth from bacterial and fungous diseases. These diseases 

 have appeared in spots, but unfortunately some of these localities were 

 those where colonies of parasites had been established, and in the whole- 

 sale destruction of the caterpillars by disease the introduced parasites 

 must have suffered severely. Knowledge has been gained, however, 

 which wiU make it more easy to select better localities for colonization 

 in the future. Several of the parasites have been found to have estab- 



