40 IMPORTED PARASITES. 



colonizations in 1909. Both had been received before, and 

 both had been colonized, but in insignificant quantities and 

 under conditions which left much to be desired. It is consid- 

 ered, therefore, that the first satisfactory and possibly the first 

 effective colonization of these parasites was accomplished last 

 year. 



Both are Tachinids, and similar in many respects to Tachina, 

 Compsilura, etc., but differ from all others and from each other 

 in many minor particulars in their life and habits. In relative 

 importance, as determined by the frequency of their occurrence 

 abroad, they are about equal in rank, and compare favorably in 

 France with any other Tachinid parasites except Blepharipa. 



It is hoped that both will establish themselves in America, 

 but their ability to do so remains to be proven, and it is hardly 

 to be expected that either will be recovered before 1911 or 1912, 

 unless some of the earlier and relatively very unsatisfactory 

 colonizations should have resulted more favorably than is now 

 believed to be the case. 



Pabasites of the Pupa. 

 Theronia sp. 

 There are at least 10 species of large, wasp-like parasites 

 which attack the freshly formed pupse of the gypsy moth, and 

 the caterpillars just previous to their transformation, and which 

 belong to the genera Pimpla and Theronia. All of them are 

 very general in their host relations, and will attack the pupffi of 

 almost any moth which they encounter under the proper con- 

 ditions; but none of them, with the exception of the several 

 varieties or species of the genus Theronia, have ever occurred 

 so abundantly in any lots of imported gypsy pup^ as to justify 

 a position among the important parasites of the gypsy moth. 

 As parasites of the brown-tail, the several species of Pimpla are 

 quite effective both in Europe and America; and Theronia is 

 also a brown-tail parasite, but of relatively less importance. 



There are three species or varieties of Theronia, inhabiting 

 respectively Europe, Japan and America, and all are very sim- 

 ilar in appearance and habits. The American species, Theronia 

 fulvescens, appears to have reached its maximum effectiveness 



