528 



INJURIOUS AND BENEFICIAL INSECTS OF CALIFORNIA. 



Distribution. — This is an exceedingly common species found all over 

 the State. 



Hosts. — The larva? appear to make little or no distinctions as to 

 aphid species and feed upon a great many, among which are: the green 

 citrus plant louse (Macrosiphum citrifolii Ashm.), the black citrus 



Fig. 322. — The large syrphid fly, Syrphus pyrastri 

 ( Linn.). Adults, enlarged twice. (Original) 



plant louse ( Toxopiera aurantice Koch), the melon aphis (Aphis gos- 

 sypii (Hover), the black peach aphis (Aphis persicce-niger Smith), the 

 cabbage aphis (Aphis brassicce Linn.), the oat aphis (Aphis avence Fab.) 

 and the mealy plum plant louse (Hyalopterus arundinis Fab.). 



