October, '10] DAVIS: ILLINOIS APHIDID.E * 413 



S. panicola Thos.: Hart 18th Rept. St. Ent. 111. (1894), 

 p, 90, 2 figs. Common on roots of Panicum and occasionally 

 on corn roots, but of little or no economic importance. It has still 

 to be proven that this is identical with >S. corni. First reported by- 

 Forbes. 



^S. querci Fitch: 5th Kept. Insects N. Y. (1859), p. 804. This 

 species has not been recorded from Illinois since the first record by 

 Fitch. I have taken a species on oak leaves several times in Northern 

 Illinois, which is, I believe, the species referred to by Oestlund and 

 Cowen as Fitch's querci. However my oak aphid, which is found in 

 colonies beneath a rather dense cottony secretion, is a Phyllaphis, 

 apparently undescribed, and will be described fully in another paper. 

 First reported by Fitch. 



* 1 S. rileyi Thos. {nlmi Riley) : Riley, 1st Rept. St. Ent. Mo. (1869), 

 p. 123. A serious pest of the elm throughout the state. First reported 

 by Riley. 



* Mindarus ahietinus Koch {■z=ipinicola Thos.) : 8th Rept. St. Ent. 

 111. (1880), p. 137; Patch, Bull. 182, Me. Agr. Expt. Sta. (1910), p. 242, 

 7 figs. This species has never been taken in Illinois since the original 

 description. First reported by Thomas. 



'^Phyllaphis fagi Linn..: Thomas, 8th Rept. St. Ent. 111. (1880), 

 pp. 120, 140; Weed, Trans. Amer. Ent. Soc, Vol. 20, p. 303, 3 figs. (?) 

 Other than in Hunter's Catalogue, this species has not been reported 

 from Illinois. 



Longistigma caryce Harr.(??): Sanborn, Kans. Uni. Sci. Bull., 

 Vol. 3 (1904), p. 30, figs. (L. longistigma). What has been here- 

 tofore known as L. longistigma on linden and L. platanicola on sycamore, 

 are common throughout the state, the winged males and wdngless 

 oviparous females making their appearance during October in North- 

 ern Illinois, the large eggs being deposited in the crevices of the bark 

 as well as on the smaller branches. First reported by Fitch (?). 



^Lachnus abietis Fitch: Cat. Homopt. N. Y. (1851), p. 67. There 

 is no record of the occurrence of this Lachnus in Illinois other than 

 in Hunter's Catalogue. 



*2L. dentatus Le B.: 3rd Rept. (2nd of Le Baron), St. Ent. 111. 

 (1872), p. 138, figs.; Weed, Bull. Ohio Agr. Expt. Sta., Tech. Ser., Vol. 

 1, No. 2 (1890), p. 117, figs. A common species in Northern IlHnois, 

 becoming very abundant in the fall, and on ornamental willows it is a 

 considerable nuisance. First reported by Le Baron (?) 



^L. quercifolice Fitch: Cat. Homopt. N. Y., p. 67, 1851. This 



^ Chicago, 111. and St. Louis, Mo., type localities. 



^ Although not definitely stated, Le Baron probably described this species from 

 lUinois specimens. 



