152 PARASITES OF GIPSY AND BROWN-TAlL MOTHS. 



IMPORTATION AND HANDLING OF PARASITE MATERIAL. 



Since insects like the gipsy moth and the brown-tail moth are sub- 

 jected to the attack of different species of parasites at different stages 

 in their development, it has been necessary, in order to secure all of 

 these, to import the host insects in as many different stages as pos- 

 sible and practicable. If the present experiment in parasite intro- 

 duction is brought to a successful conclusion, it will undoubtedly 

 encourage the undertaking of other experiments in which similarly 

 imported pests are involved. Even should it fail, from a severely 

 practical standpoint, and the complete automatic control of neither 

 the gipsy moth nor the brown-tail moth should be effected, it seems 

 to us that the technical results already achieved are sufficient to give 

 encouragement rather than the opposite to similar undertakings in 

 the future. It is therefore desirable to describe in some detail the 

 various methods employed for the importation and subsequent 

 handling of the parasite material. 



With very few exceptions the methods first employed proved more 

 or less unsuitable. Sometimes they were entirely discarded; usually 

 they were modified to suit the exigencies of the occasion. Some- 

 times these modifications were in comparatively unimportant par- 

 ticulars which would scarcely be pertinent to any other insect than 

 the gipsy moth or the brown-tail moth, and realizing this there will 

 be no attempt in such cases to enter into lengthy descriptions. At 

 other times radical modifications have been found necessary on 

 account of unforeseen difficulties which would be likely to occur in 

 pretty nearly any other undertaking along anything like similar lines. 



EGG MASSES OF THE GIPSY MOTH. 



The importation of egg masses of the gipsy moth (see PI. VI) 

 from European sources has been attended with no difficulty whatever, 

 beyond that of securing the collection of these eggs in sufficiently 

 large quantities. Any style of package, provided that it were suffi- 

 ciently tight to prevent loose eggs from sifting out, was as good as 

 another, and any one of the established means of transportation 

 served the purpose. 



In the case of shipments from Japan serious difficulties were 

 encountered. One of the parasites peculiar to that country and 

 unknown in Europe invariably issued en route and died without 

 reproducing. Various attempts to overcome this difficulty without 

 having recourse to cold storage failed and it was only after cold- 

 storage facilities were perfected and used that living parasites of this 

 species were secured in numbers. 



As in the instance of similar shipments from Europe, no special 

 form of package was required, but at the same time a word of appre- 



