THE CANADIAN ENTOMOLOGIST. 385 



NOTES ON LACHNUS CARY^E, HARRIS, UNDER A NEW 



NAME. 



BY H. F. WILSON, U. S. DEPT. AGR., BUREAU OF ENTOMOLOGY. 



On comparing the descriptions of Harris, Monell and Riley, and 

 specimens of this species collected from hickory, black oak, sycamore and 

 basswood, I am of the opinion that Lachnus longistigma, Monell, and 

 Lachnus platanicola, Riley, are synonyms of the above species, which 

 conclusions were reached after collecting a large number of specimens, 

 and a careful study of all forms from different host plants. I have also 

 concluded that this so-called Lachnus is not a Lachnus, and have formed 

 a new genus, with this species as the type of the genus. 



Longistigma, n. g. 



The name Longistigma is given on account of the extremely long, 

 slender stigma which reaches around the end of the wing. 



The honey tubes are short, conical and of fair size. The stigma and 

 honey tubes are the distinguishing characters. Antennte and wing-veins 

 similar to those of the genus Lachnus. 



Longistigma caryce, Harris. 



Synonymy : Aphis caryce, Harris, Ins. Inj. Veg., 1S41; id., Flint, ed , 

 1862 ; Lachnus caryce, Rept. Ins. N. Y., 3: 443, 1856; Walsh, Proc. Ent. 

 Soc. Phila., 1 : 302, 1S61 ; Thos. Rept. Ent. 111., 8: 116, 1880; Oestl. 

 Aph. Minn., 32, 1887 ; Packard, Forest Ins., 299, 323, 1890. 



Lachnus longistigma, Monell, Valley Naturalist, June, 1878 ; Thos. 

 Rept. E'nt. 111., 8 : 1 rg, 1880; Townsend, Ins. Life, 2 : 90, 1889 ] Oestl. 

 Aph. Minn., 32 : 1887 ; Osborn, Cat. Hem. la., 29, 1892. 



Lachnus platanicola, Riley, Am. Nat., 17 : 198, 1883 ; Townsend, 

 Ins. Life, 1 : 197-198, 1889; Oestl. Aph. Minn., 32, 1887 ; Weed, Ins. 

 Life, 3 : 286-287, pi. 1, fig. 1-4, 1892. 



Collected by myself, September 27, 1909, on hickory, black oak, 

 basswood, sycamore and silver-leaf maple. 



This is without doubt the largest species yet known in America, and 

 should not be easily mistaken. Those specimens on the oak have wings 

 darker than those on the other host plants, but this is probably due to 

 the food. On the same host plants this species varies considerably in 

 size and colour. 



In the vicinity of Washington the eggs hatch as early as March nth, 

 and the egg-laying females can be found as late as Dec. 2nd. 



November, 1909 



