FARMERS BULLETIlSr 804, 



SEASONAL HISTORY. 



The eggs of this aphid are laid upon the peach twigs, and early in 

 the spring before the buds are opened the green stem-mothers are 



hatched. From this form dur- 

 ing the spring may be produced 

 one or more generations of 

 wingless individuals upon the 

 leaves. Spring migrants, how- 

 ever, begin to occur very early 

 and continue to appear until 

 the middle of June. These fly 

 to a large number of different 

 plants, where numerous genera- 

 tions occur throughout the sum- 

 mer. During September and 

 October fall migrants are de- 

 veloped which return to the 

 peach, where they deposit the 

 young egg -laying females. 

 These are fertilized bj^ the 

 winged males, which also have 

 returned to the peach, and the 

 females then lay their eggs upon 

 the twigs. Occasionally, how- 

 ever, migrants are found which 

 do not return to the peach and ' 

 these deposit egg-laying females 

 upon the summer host plants. 



THE BLACK PEACH APHIS.^ 



The well-known black peach 

 aphis is injurious to the twigs, 

 shoots, and roots.. It is shiny 

 dark brown to black, with the 

 young an amber color. 



The insect lives throughout 

 the 3^ear on the roots of the 

 peach and is most injurious to 

 peach growing on sandy soils. 

 It is prevalent in portions of 

 Maryland and in Delaware, 

 New Jersey, and Michigan. 

 Individuals migrate from the roots during the warm periods in 

 ninter or in early spring and start colonies on the twigs and young 

 shoots. (Fig. 19.) Often these become so numerous as to cause the 



Fig. 19. — The black peach aphis (Aiihin pcr- 

 sicac-nigcr) : Colonies on peach shoot in 

 early spring. (Original.) 



Aphis pcrsicac-nli/cr Smith. 



