PLANT-LICE INJURING THE FOLIAGE 



317 



The Rosy Apple Aphis (Aphis sorbi) hatches from eggs that have 

 remained on the apple throughout winter, but with the third generation 

 migrates to other food 

 plants. This is a slightly 

 larger species. The wing- 

 less female is one tenth of 

 an inch long, bluish in 

 color, and has yellow honey 

 tubes tipped with black. 

 The winged female has a 

 black thorax and a red ab- 

 domen. 



The European Grain 

 Aphis (Siphocoryne avence) 

 is found in summer on 

 small grains, but for the 

 most part migrates in the 

 fall to apple, pear, or re- 

 lated trees, where its win- 

 ter eggs are laid. It develops in the spring like the preceding 



species, leaving the fruit 

 trees with the coming of the 

 third generation. On apple 

 trees it is commonly first 

 observed clustered on the ex- 

 panding buds. 



The Clover Aphis {Aphis 

 hakeri) rears its summer gen- 

 erations on clover or alfalfa. 

 These lice are light yellow or 

 pink. Usually they leave 

 the clover in the fall, passing 

 through a winter egg stage 

 on apple or pear. The first 

 generation from these eggs 



Fig. 487. — Adults of the Apple Aphis clus- 

 tered along veins of leaf. Enlarged. Orig- 

 inal. 



Fig. 



488. — Work of Aphi. 

 Original. 



young fruit. 



