532 INSECT PESTS OF FARM, GARDEN AND ORCHARD 



are more liable to be attacked by other insects and diseases, 

 while the premature dropping of the foliage prevents the full 

 growth of the tree and the proper hardening of the wood before 

 winter. This species shows marked preference for certain varieties 

 of apples and rarely injures others. Apple, pear and quince are 

 the only fruit trees infested by this species, which lives upon 

 them throughout the year. 



These lice may also attack the fruit as it begins to set, causing 

 some dropping and a considerable amount of distortion to the 



FIG. 461. The apple-aphis, winged fall migrants on leaf natural size. 



fruit. Such fruits .rarely attain full size and may easily be recog- 

 nized at picking time. The rosy-aphis causes somewhat similar 

 injury which may be even more severe. In normal years the 

 injury to the fruit amounts to as much as the injury to the foliage. 



The Rosy Apple-aphis * 



This species is larger than the preceding, with a rounder body, 

 and is commonly of a rosy color, though the wingless females 

 vary from a salmon or tan color to slaty gray, purplish or black. 

 It has been injurious only to apple in this country, where it has 

 become widely distributed, but in Europe its native food-plants 

 are various wild species of Sorbus and Cratoegus. The wingless 

 female is about one-tenth inch long, the head, thorax and margin 



* Aphis sorbi Kaltenbach. Family Aphididce. See Sanderson, and Gillette 

 and Taylor (Aphis pyri Boyer), cited above; and W. E. Britton, 9th Report, 

 State Entomologist of Connecticut, p. 343, also other citations below "Apple 

 Plant-lice," and A. C. Baker and W. F. Turners, Jour. Agr. Research, Vol. 

 VII, No. 7. 



