INSECTS INJURIOUS TO PEACH, PLUM AND CHERRY 595 



The Black Cherry-louse * 



This species has long been known as a cherry pest in Europe 

 and during the last fifty years has become generally distributed 

 over the eastern United States, and occurs in Colorado. So far 

 as known the cherry is the only food-plant. Dr. Weed was of 

 the opinion that the aphids left the cherry during late July and 

 migrated to some summer food-plant which he was unable to 

 find, but observations by Gillette and Taylor in Colorado would 

 indicate that they may remain on the cherry, but become so 

 reduced in numbers by their natural enemies that only a few 

 survive during midsummer, and these give rise to larger colonies 

 in late summer and early fall. Both the winged and wingless 

 forms are deep shining black, the body is rather broad and flat, 



Fia. 522. The black cherry-aphis (Myzus cerasi Fab ): 1, apterous vivip- 

 arous female; 2, winged viviparous female enlarged. (After Gillette 

 and Taylor.) 



and the honey-tubes are unusually long and are cylindrical. 

 Small winged males and wingless females occur on the foliage in 

 the fall and the latter lay their eggs on the twigs about the buds. 

 Like the black peach-aphis, this species has the habit of accumula- 

 ting in large numbers on the smaller sprouts or limbs near the 

 ground before spreading to the rest of the tree or other trees, so 

 that prompt treatment when first observed will prevent general 

 infestation. 



Control. Spraying as for the apple-aphis (p. 537), will control 

 the pest. 



* Myzus cerasi Fab. Family Aphididce. See C. M. Weed, Bulletin Ohio 

 Agr. Exp. Sta., Tech. Ser., Vol. I, No. 2, p. Ill; C. P. Gillette, Journal of 

 Economic Entomology, Vol. I, p. 362. 



