Vol. IJ 



Essig. — Aphididae of California 



313 



which arise short spines. The dark areas increase in size towards 

 the posterior end. The cornicles (fig. 7, 5), the cauda and the 

 anal plate are much the same as in the apterous form already 

 described. 



HOST PLANTS, LOCALITIES, DATES AND COLLECTORS 



This species feeds in compact colonies on the bark and very 

 rarely on the leaves of the coast live oak, Quercus agrifolia Nee. 

 As already stated apterous forms were first taken by S. H. Essig 



Fig. 7. Symydobius agrifoUae, n. sp. Winged viviparous female. A, 

 dorsal aspect; B, cornicles; C, antenna. (Original.) 



and the writer in Santa Panla Canon, near Santa Paula, Cali- 

 fornia, on July 21. 1911. Apterous forms as well as winged were 

 also taken by the former collector in the same locality on May 

 27, 1916, as well as along the Ventura River near Ventura, Cali- 

 fornia, on June 21, 1916. 



Symydo'bius agrifoUae, n. sp. is closely related to Symydohius 

 alhasiphus Davis, but is at once separated by having a much 

 shorter spur on the sixth antennal article as well as other differ- 

 ences. 



