126 



THE SPRING GRAIN-APHIS OR ' ' GREEN BUG." 



that had not previously been parasitized; he experienced no diffi- 

 culty, however, in rearing it when the adults were placed in cages 

 with aphidids that were brown, having been killed by some species 

 of Aphidius. It may be that under certain conditions Megorismus 

 sp. is also a primary parasite. Mr. Parks finds that it takes about 

 30 days in developing from egg to adult in a temperature of about 

 70° F. indoors. 



It has been reared in conjunction with Aphidius sp. from Toxoptera 

 graminum and CJiaitophorus sp. at Wellington, Kans., by Messrs. 

 Kelly and Urbahns; from T. graminum and Aphis hrassicse in the 

 same locality by Mr. Parks. Mr. Parks also reared it from Macrosi- 



Fig. 34. — Megorismus sp., a secondary parasite of the spring grain-aphis: Male, greatly enlarged; female 



abdomen, more enlarged, at right. (Original.) 



phum pisi at Washington, D. C. Mr. C. N. Ainslie reared it from 

 Hyalopterus dactylidis in the same locality, and the junior author 

 reared it from Myzus persicse at Lafayette, Ind. 



Aphidencyrtus aphidiphagus Ashm. 



The species Aphidencyrtus aphidiimagus Ashm. (fig. 35) has also 

 been considered a primary parasite, and while we have no direct 

 evidence to disprove this we very strongly suspect that it is in this 

 case a secondary parasite. Like Megorismus, which, we have shown, 

 is sometimes, at least, a secondary parasite, we have reared it only 

 in conjunction with known primary parasites. Mr. G. G. Ainslie 

 could rear it only in connection with Aphelinus sp. from T. graminum 

 at Clemson, S. C, and Mr. C. N. Ainslie reared it from Aphis 



