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University of California Publicatiois [Entomology 



Rhopalosiphum rlwis ^Nlonell. A dark green or black shiny 

 aphid occurring abundantly on the tender shoots of the poison 

 oak, Rhus diversiloha T. & G., during the spring and early sum- 

 mer, but entirely disappearing by the middle of summer. Often 



Fig. 20. Myzus varians Davidson. Curled leaves of tender peach shoot 

 caused by this insect. Berkeley, Cal., June 7, 1916. 



causes severe curling of the leaves. Campus, July 3, 1916 — only 

 a very few were to be found at this date. (See B. howardii 

 Wilson). 



Myzus cerasi (Fab.) (fig. 19). A shiny black aphis with long 

 cornicles, occurring in large dense colonies on the shoots and 



