December, '10] davis: Illinois aphidid^ 483 



p. 157, 2 figs. Common in Central Illinois on the red haw (Cratcegus 

 coccinea.) 



*A. carduella Walsh: Oestlund, Bull. Geol. and Nat. Hist. Surv. 

 Minn., No. 4 (1887), p. 59. First reported by Walsh. I am unac- 

 quainted with this species. 



*A. cardui Linn. : Oestlund, Bull., Geol. and Nat. Hist. Surv. Minn., 

 No. 4 (1887), p. 65. A very common species on the purple thistle, 

 invariably attended by ants {Formica sp.). 



^A. cephalanthi Thos.: Davis, Annals Ent. Soc. Amer., Vol. II 

 (1909), p. 40, figs. Not uncommonly injuriously abundant on the 

 button-bush shrub {Cephalanthus occidentalis) , which is often used in 

 ornamental plantings. It usually becomes most abundant in the 

 fall of the year. First reported by Thomas. 



*A. cerasifolioB Fitch: Oestlund, Bull. Geol. and Nat. Hist. Surv. 

 Minn., No. 4 (1887), p. 51. A serious pest of Primus pennsylvanicus, 

 a shrub commonly planted in parks, and living on the undersides of the 

 leaves, curhng them badly, and thus seriously disfiguring the natural 

 beauty. I have found them so abundant as to disfigure every leaf 

 on a clump of these shrubs and to cause the leaves to turn brown and 

 often fall off in midsummer. 



*A. coreopsidis Thos.: 8th Kept. St. Ent. 111. (1880), p. 59, figs.; 

 Oestlund, 14th Kept. Geol. and Nat. Hist. Surv. Minn. (1886), p. 

 38, {A. frondosce). Last fall (1909) this species became very abun- 

 dant at Oak Park, 111., infesting the stem, leaves, fiowers, and flower 

 stalks, principally the two latter, of Bidens indgata, and this fall 

 (October 3, 1910) I found it rather common on Bidens hipinnata at 

 Anna, Illinois. Infested plants in confinement were continually 

 watched until the plants and aphids were killed by the cold, with no 

 sign of an oviparous generation. Noticing the marked resemblance 

 between the descriptions of Siphonophora coreopsidis Thos. and 

 A. frondosce Oestl., I wrote Professor Oestlund who kindl}^ sent me 

 a mounted specimen of his species. I have thus been able to posi- 

 tively identify my Oak Park specimens as the species described as 

 A frondosce. Mr. Monell has sent me specimens from Coreopsis 

 collected in St. Louis, which he determined as A. coreopsidis and 

 also a copy of the original type color notes. From all these sources 

 I have studied and compared my species and conclude that the two 

 species, A. frondosce and A. coreopsidis, are synonymous. In all 

 specimens the color notes and habits agree quite well. Mr. Monell's 

 specimens were smaller but the relative antennal measurements 

 agree with my specimens excepting in some specimens the length of fila- 

 ment VI is longer, but this appears to be quite variable and can 

 hardly be considered of specific value. Camera lucida drawings, of 



