A SYNOPSIS OF THE APHIDIDAE 25 



Buckton. Recently the author described the species from specimens 

 taken in Berkeley on chestnut and oak. It cannot be the Callipterus 

 castaneae of Fitch, because the latter is really a Calaphis. It may be 

 the same species that Buckton had when describing his Callipterus 

 castaneae, in which case his name would be dropped as Fitch's species 

 has priority, and is replaced by the author's name, M. davidsoni. It 

 is more or less common throughout the San Francisco Bay region on 

 chestnuts, and in one case on two specimens of Quercus pedunculata 

 in Berkeley. The stem mothers appear during the late spring, in 

 April and May. Viviparous generations are produced throughout the 

 summer, the sexuales occurring in October and November. 



]6. Myzocallis coryli (Goetze) 



Figures 43, 44, 53, 54 



Goetze, Ent. Beitrage, vol. 2, p. 311, 1778. Aphis (orig desc.). 

 Clarke, Can. Ent., vol. 35, p. 249, 1903. Callipterus (list). 

 Davis, Jour. Econ. Ent., vol. 3, p. 417, 1910. Callipterus (desc.). 

 Essig, Pom. Jour. Ent., vol. 4, p. 762, 1912 (list). 



Records. Corylus sp., Berkeley (Clarke) ; Corylus rostrata, San Francisco Bay 

 region (Davidson) ; C. rostrata var. calif ornica, C. maxima, Berkeley, August, 

 1914, June to July, 1915. 



In the San Francisco Bay region this species is quite common on 

 alder. During the seasons of 1914 and 1915 the author observed it 

 to be very abundant on species of alder on the University of California 

 campus. He has never found it in the south, however. 



17. Myzocallis discolor (Monell) 



Figures 262, 263 



Monell, U. S. Geol. Geog. Surv., Bull. 5, p. 30, 1879. Callipterus (orig. 



desc.). 

 Williams, Univ. Neb. Studies, vol. 10, p. 115, 1910. Callipterus (desc.). 



Record. Quercus macrocarpa, Sacramento, October, 1916 (Davidson). 



The author received specimens of this species from Davidson, 

 which were found in October, 1916, on Quercus macrocarpa in Sacra- 

 mento. The determination was made by Davis. Below are a few 

 descriptive notes to supplement Williams' description listed above. 



Alate viviparous female. Antennae about as long as body, III 

 the longest segment, followed by IV, VI, and V. VI spur is slightly 

 longer than the base. The antennae are rather slender as compared 



