A SYNOPSIS OF THE APHIDIDAE 123 



of A. gossypii Glover, but as the author has not had an opportunity 

 to study specimens he believes it best to recognize it as a distinct 

 species at present. 



144. Aphis salicicola Thomas 



Figures 188, 238, 237 



Thomas, 111. Lab. Nat. Hist., Bull. 2, p. 8, 1879 (orig. desc.). 

 Williams, Univ. Neb. Studies, vol. 10, p. 139, 1910 (desc.). 

 Davidson, Jour. Econ. Ent., vol. 5, p. 408, 1912 (list). 



Records. Salix laevigata; Berkeley, June, 1915: Salix, sp. ; San Jose (David- 

 son). 



This is an uncommon species, found in the San Francisco Bay 

 region on willow. The individuals are found in large colonies on 

 the terminal shoots and leaves. These colonies consist in large part 

 of apterae, there being but a very few alates. The species is quite 

 easily recognized by the long cornicles and by the very short second 

 branch of the third discoidal vein. 



145. Aphis sambucifoliae Fitch 



Figure 240 



Fitch, Cat. Homop. N. Y., p. 66, 185 (orig. desc.). 

 Sanborn, Kan. Univ. Sci. Bull. 3, p. 52, 1904 (dese.). 



Records. Sambucus glauca; Oakland, April, 1915 (Essig) ; Berkeley, July, 

 1915. 



In 1915 this species was taken twice, once by Essig in Oakland 

 and once by the author in Berkeley. This medium-sized black aphid 

 occurs in large colonies on the tender shoots and flower heads of the 

 common elderberry. In southern California the author has examined 

 hundreds of elderberry trees for this form, but has never found it. 

 Only once has he found any aphid on elderberry in the south, and 

 these proved to be Rhopalosiphum persioae (Sulz.). 



146. Aphis senecio Swain 



Figures 2, 4, 6, 241 to 245 



Davidson, Jour. Econ. Ent., vol. 2, p. 302, 1909. Aphis sp. (list). 

 Davidson, Jour. Econ. Ent., vol. 3, p. 377, 1910. A. bakeri Cowen (list). 

 Davidson, Jour. Econ. Ent., vol. 7, p. 133, 1914. A. bakeri Cowen (list). 

 Swain, Trans. Am. Ent. Soc., vol. 44, p. 16, 1918. 



Records. Abutilon sp. ; Stanford University, February, 1915: Ambrosia 

 psilostachya; Berkeley, 1915 (Essig): Amsinckia spp. ; Stanford University, 1909 

 (Davidson), 1912 (Morrison); Berkeley, 1915 (Essig): Anthemis spp.; San 



