BUREAU OP ENTOMOLOGY. 255 



Experimental work. — During the fall collections were made to 

 determine the status of one of the egg parasites of the gipsy moth, 

 Schedius kuvanae. The results were more satisfactory than hereto- 

 fore, and it was possible to rear large numbers of this species and to 

 colonize them in infested towns where this species had not been 

 liberated previously. Nearly 2,000,000 specimens were released late 

 in September and October. 



In November collections were begun to determine the percentage 

 of parasitism by Anastatus hifasciatus^ a single-brooded egg parasite 

 of the gipsy moth. The collections that were made in the regions 

 where this parasite was first liberated gave the most satisfactory per- 

 centage of parasitism that had ever been secured. Material was col- 

 lected for use in colonizing this insect the following spring, but, al- 

 though the egg clusters were handled in the same manner in the 

 laboratory as heretofore, the number of eggs producing live parasites 

 was considerably less than had been secured in previous years, so 

 that it was possible to liberate this spring less than 2,000,000 speci- 

 mens. It is probable that both of these species will not survive in 

 maximum numbers such severe winter conditions as existed during 

 the past year. Further work later in the season will show how severe 

 the mortality has been. 



Parasitism by Com'psilura concinnaia averaged higher during 1917 

 than heretofore, and this species was reared from a number of native 

 caterpillars that were not previously known to be hosts of this para- 

 site. Blepharijoa scutellata^ a tachinicl fly which parasitizes large 

 gipsy moth caterpillars and emerges from the pupse, was recovered 

 in much larger numbers in the summer of 1917 than in any other year 

 since' its introduction. 



A new method has been devised for breeding specimens of Apan- 

 tel.es melanoscelus for colonization, and it has worked out very satis- 

 factorily. This species passes through two generations in the field, 

 the first attacking the small gipsy moth caterpillars and the second 

 destroying the nearly full-gi'own larvae. 



The Calosoma beetle has been found in limited numbers in many 

 widely separated parts of the infested area, and is more abundant 

 than usual in the sections that are badly infested. 



There were no severe infestations by the brown-tail moth this 

 summer, and there has been a corresponding decrease in the abun- 

 dance of the imported parasites that attack this insect. 



The work on diseases affecting the gipsy moth and brown-tail moth 

 has been confined principally to an attempt to determine the abun- 

 dance of the brown-tail moth fungus in the winter webs, study of the 

 value of an unnamed fungous disease which has been found in eggs 

 of the gipsy moth, and study and liberation of a bacterial disease 

 which originated in Japan and attacks the gipsy moth caterpillars 

 in the field. 



Little evidence has been secured during the past two winters that the 

 brown-tail moth fungus winters in any quantity in the webs of this 

 insect. The investigations on the disease found in eggs of the gipsy 

 moth have not progressed far enough to warrant conclusions as to 

 the extent to which this disease is responsible for nonhatch of eggs. 

 The study of the Japanese disease of the gipsy-moth caterpillars 



