THE CANADIAN ENTOMOLOGIST. 219 



NOTES ON THE APHID GENUS, ERIOSOMA LEACH. 



BY H. F. WILSON, OREGON AGRICULTURAL COLLEGE. 



Eriosoma lanigera versus Schizoneura lanigera. 



At various times since the description and naming of Houstnann's 

 Aphis lanigera different authors have erected generic names for this species. 



There seems to be no doubt of the validity of the specific name for 

 the species of Aphis originally described by Housmann as Aphis lanigera^ 

 but the generic names erected for this insect have been more or less in 

 doubt. 



The author of this paper has made a thorough investigation of all the 

 known literature, and concludes that Eriosoma was erected and definitely 

 placed with this species, and that Schizoneura and other later names are 

 synonymic as far as this species is concerned. Samouelle is generally 

 supposed to have originated the genus in his compendium of useful infor- 

 mation, but such is not the case. In 1817 Sir Oswald Mosely gave a 

 paper before the Horticultural Society of London, entitled, ''Aphis 

 lanigera or American Blight." At the end of this article a note is appended 

 by Dr. William Elford Leach, in which he mentions Aphis lanigera of 

 Housmann, and concluding that a new genus should be made for this 

 species he proposes the name Eriosoma. The note appended to the 

 original paper reads as follows : "Note on the Insect, by William Elford 

 Leach, M.D., F.R.S., etc. The animal of which so accurate an account is 

 given in the preceding paper is the Aphis lanigera of Housmann ; it is 

 described by the author in Illiger's Magazine for 1802, page 440, and is 

 referable to Latreille's third division of the genus Aphis, but which division 

 I consider to constitute a peculiar genus distinct from Aphis, and which I 

 have named EriosomaT 



Eriosoma has its body covered by woolly matter ; its abdomen has 

 neither horns nor tubercles, and its antenme are short. The body of Aphis 

 is naked, its antennae are long and setaceous, and the abdomen is furnished 

 with a tubercle or horn-like process on each side. 



Although this paper was read in 181 7, it evidently was not published 

 until 1 8 18, in the latter half of that year. The entire article is printed in 

 Volume in. Trans. Hort. Society, London, 1820, pages 54 to 01. The 

 preface to this volume is dated January, 1820, but reads, "When the 

 Society completed the second volume of their Transactions in I\Lirch, 

 18 18, arrangements were made to insure, if possible, the i)ublication of 



July, 1912 



