6 



in the fall, oviposition beginning somewhat earlier than but overlap- 

 ping with that of the preceding species; they are placed in similar 

 situations, and are not distinguishable from those of SipJiocoryne 



Fig. 4 — Apple aphis (Aphis laali):. a, winged agamic form; b, pupa; c, wingless agamic form; d, 

 recently born aphis. All greatly enlarged (original). 



avenae. They hatch perhaps somewhat later in the spring, and after 

 the foliage is further advanced and, like the species next considered, 

 the aphides developing from them cause a greater curling of the 



leaves. The apple leaf- 

 '^''''^^''"^^^^'^'^'^''-^'^-^^^^ aphi^; infests the apple 

 throughout the 3'ear and 

 for this reason is capable of 

 more injury than the other 

 species herein treated. 

 Upon the hatching of the 

 winter eggs in spring a 

 succession of agamic gen- 

 erations is produced, the 

 earlier ones, except the 

 first, with numerous winged 

 individuals which migrate 

 to other trees and estab- 

 lish new colonies. In New Jersey, as found by Doctor Smith, there 

 may be during the season seven agamix3 generations followed by the 

 development of the sexual wingless males and females (tig. 5) in the 

 fall. 



[Cir.81] 



Fig. 5.— Apple aphis (Apliis mali): The true sexual forms 

 (I, male; b, female. Greatly enlarged (original). 



