178 JOURNAL OF ECONOMIC ENTOMOLOGY [Vol. 10 



holds great opportunities for such work. With this in view it was 

 suggested by Mr. A. F. Burgess that a paper deahng with some of the 

 methods that are being used for colonizing imported parasites and 

 checking their status in their new environment would prove of interest 

 and value to others who are working with similar projects. 



The methods used in introducing and establishing a new insect 

 depend entirely upon its habits, life cycle, and seasonal history. In 

 the time allotted for this paper, it would be difficult to deal in detail 

 with the many parasites which are receiving attention at the Gipsy 

 Moth Laboratory. Accordingly, I shall discuss the methods used in 

 handling only two species, namely, Anastatus hifasciatus Fonsc. and 

 Schedius kuvance How. These insects belong to the family Encyrtidce 

 and parasitize the eggs of the gipsy moth; otherwise they have little 

 in common. 



The story of the importations and successful establishment in 

 America of these parasites is a fascinating one and has been reported by 

 Howard and Fiske in Bulletin 91 of the Bureau of Entomology. Both 

 were successfully colonized during the summer of 1909, Anastatus 

 being liberated as larvae within imported gipsy moth eggs, while 

 Schedius were released as adults, which were obtained by breeding at 

 the laboratory. 



It is essential that the life and seasonal histories of the host and 

 parasite be known before work of this nature can be done intelligently. 

 The seasonal histories of the parasites with which we are dealing are 

 briefly as follows: Schedius hibernates as an adult. In the spring, a 

 week or two before the gipsy moth eggs hatch, these hibernated in- 

 dividuals may be found ovipositing in gipsy moth eggs, starting a 

 spring generation, the progeny of which carries the species through 

 the summer. In July soon after the gipsy moth eggs are laid, Sche- 

 dius attacks them and a generation is produced about every twenty-five 

 days, until cold weather sends them to their hibernating quarters. 

 Four generations and a partial fifth are completed each fall by Sche- 

 dius. Anastatus, on the other hand, like its host, has but a single 

 generation. Very soon after the gipsy moth lays her eggs, Anastatus 

 oviposits in them and the larva of the parasite devours the egg contents 

 before the embryo has time to develop. It remains within the host 

 egg through the winter and early summer, until a week or so before the 

 gipsy moth eggs are laid, and after pupating the adult parasite issues 

 and attacks the new eggs. It is important to note that these parasites 

 do not disperse at an equal rate, Anastatus spreading much slower 

 than Schedius. Also that Anastatus has but one generation each year, 

 while Schedius has several generations. These facts have an important 

 bearing on the plans of work. 



