148 



FRUIT INSECTS 



generation of true males and females, which are wingless, appear, 

 mate and continue to lay their shiny black eggs on the bark for a 



month or more. The light green, 

 oviparous females have peculiar sen- 

 sory pits on their hind tibise and are 

 about two thirds as large as the par- 

 thenogenetic wingless summer forms. 

 The yellowish-brown males, with 

 blackish antennae longer than the 

 body, are one third smaller and much 

 less numerous than the females. 



This species usually appears some- 

 what later in the spring than the 

 more common apple ])ud aphis, and 

 it is thus not so numerous on the 

 buds, waiting until the leaves are unfolded. As it breeds 

 on the trees during the whole season it may be more injuri- 

 ous than the other two species. Its work resembles that of 



Fig. 160. — Apple leaf-aphis 

 apterous viviparous female. 



Fig. 161. — Apple leaf-aphis, winged viviparous female, third generation. 



the rosy apple aphis, the leaves often being curled very badly. 

 In 1907 it was so numerous in many large, bearing orchards in 

 New York that it swarmed on to the young fruits in June, 

 checked their growth, prevented the normal June drop, and gave 



