BULLETIN No. 181. 



GALL APHIDS OF THE ELM.* 

 Edith M. Patch. 



Introduction. 



The study of this Httle group of elm aphids involves various 

 problems, certain of which may be outlined here, as they add 

 an interest to the species concerned. 



Coloplia ulmicola is considered by some the same as Colopha 

 comprcssa of Europe. Even if this be the case, I have chosen 

 to retain the American name for this species because it seems 

 discreet to be entirely sure of the relations of this insect in one 

 country before getting it involved with European problems. 



So far as the literature is concerned the cockscomb gall in 

 America has been so constantly associated with Colopha ulmi- 

 cola that it was with considerable surprise that I found that the 

 species issuing from the cockscomb gall in Maine in 1909 was 

 not a Colopha but a Tctrancura. This cockscomb Tetraneura 

 was, it seems, first taken by that most excellent observer Mr. 

 Pergande years ago and in a correspondence with Mr. Monell 

 received the name of Tctrancura colophoidea Monell mss. This 

 species was described and figured under the name of Tctra- 

 ncura uliiii (by error) by Mr. Sanborn,! but the name of colo- 

 plioidca never escaped manuscript except in a paper "Upon the 

 Aphis-feeding Species of Aphelinus" by Doctor Howard,^ 

 where it was merely mentioned. 



The differences between T. colophoidea and C. ulmicola ex- 

 cei'it for the venation are perliaps not such as would definitely 



*Papers from tlic Maine Agricultural Experiment Station : Entomol- 

 ogy No. 43. 



tKansas Aphid, page 23. 



tEnt. News, October 1908, p. 365. 



