150 



FRUIT INSECTS 



stem-mothers, develop into parthenogenetic winged forms (Fig. 

 162) that migrate from the apple trees to some miknown food- 

 plant during the latter part of June in New York. In 1893 we 

 tried to colonize these spring migrants on various grasses, but 



failed, and did not see the species 

 again until September, when shiny 

 black winged viviparous females 

 or migrants appeared on the apple 

 leaves. These were darker than 

 the migrants which left the trees 

 in the spring and differed slightly 

 in other details. Early in October 

 a progeny of globose, light yellow 

 or brownish colored wingless ovip- 

 arous females, with many sensory 

 pits on the hind tibiae, began to 

 be born from the winged return mi- 

 grants. Soon winged males, which 

 resembled the somewhat larger re- 

 turn migrants, came from unknown 

 sources and mated with the wingless females, which began laying 

 their shiny black eggs on the twigs, and often on the trunk also. 

 Although working on the apple tree only about two months in 

 the spring, this rosy apple aphis is capable of doing much injury. 

 It often curls the leaves as badly as the preceding species, A. 

 pomi, and in 1903 it helped this species in its very destructive 

 work on the young fruits. In 1907 another of these unusual 

 devastations on the fruit by plant-lice occurred in June in New 

 York apple orchards, and this time the principal depredator 

 was this rosy apple aphis. 



Fig. 162. — The rosy apple 

 aphis, a parthenogenetic female 

 of the third generation, with 

 wing pads. 



References 



Del. Agr. Exp. Sta. 13th Kept., pp. 149-156. 

 U. S. Bur. Ent. Circ. 81. 1907. 



1902. 



