6 



Report for 1S56) a very interesting: article on the grain Aj)hix {Aphis 

 aveita^ Fab.), in which he made the unfortunate mistake of confound- 

 ing several other species with the true grain louse; erroneous figures 

 of one of which were published on PI. 1, figs. 5 and 6, representing a 

 species of Siphonophora Koch. This error of judgment in distinguish- 

 ing genera as found upon grain has mainly ])een the cause to divert the 

 attention of later entomologists from the true characters of the species 

 described 1)}^ Fabricius. 



Until the spring of 1880 the writer also entertained the opinion that 

 the species treated of by Prof. Cyrus Thomas, in his Eighth Report 

 (pp. 51-55), was identical with that mentioned and described by Fitch as 

 Aphis avencV Fal). During the spring of 1880, however, the writer' 

 became suspicious that something was wrong, since the description 

 given b}' Thomas did not agree with that published by Fabricius. At 

 that time I happened to examine a lot of aphides from Pocomoke City, 

 Md., which w(>re reported to be extremely numerous and destructive 

 to wheat in that vicinity. These, in my opinion, agreed exactly with 

 the description of Aphis avenge, Fab., and Kaltenbach, but not with the 

 description by Thomas, and I have held to this opinion ever since. 

 The same form, having l)een found h\ m3'self or received from various 

 localities, infesting grains or grasses, agrees well with the description 

 of the species published by Fitch, but not with that of Thomas. 



In consulting Mr. O. W. Oestkind's description of his Nectarophora 

 granaria (Aphididic of Minijesota, p. 82, 1887), I am forced to believe 

 that the species observed l/v him is also the same as the A. (/venfe Fab,, 

 though, having failed to oljtain any specimens from him, I am unable, 

 at present, to verify my suspicion. 



While consulting the original notes of Doctor Fitch, I found also a 

 clipping from the Kingston (Canada) Daily News, of August 10, 1866, 

 containing an article on the grain louse which was doing much damage at 

 the time. The article was written by a Mr. Lawson, of the Botanical 

 Society of Canada, who considered the insect as new, and in the same 

 article he described it under the name of Aphis tritici. After a care- 

 ful scrutiny, T am confident this is the same as A. aven» Fab. , but, since 

 descriptions of insects in newspapers are not considered as authori- 

 tative, I have declined to recognize his name of the species. 



During the fall of 1880, while solving the life history of the hop 

 louse {Phorodon humuli) at Richfield Springs, N. Y., at a time when 

 the return migrants of the apple louse were very abundant on the 

 leaves of apple trees or still swarming, I happened to discover also 

 some colonies, both of the migrants and the apterous forms, in various 

 stages of development on the leaves of a grass, Dactylis glomerata., 

 growing in the orchard. After careful comparison of these with 

 others on the apple, which, up to a comparatively recent time the writer 

 had considered identical with the European apple louse, A. utali Y)^Qi. 



