152 



jury was very prevalent in orchards in western New York. 



Three species of aphis are likely to occur upon our 

 fruit trees in early spring. The European grain aphis* is a 

 general feeder, having been recorded as occurring upon ap- 

 ple, pear, quince and plum, and such grains as rye, oats and 

 wheat. This insect winters as jet black eggs deposited by 

 the females in the fall around the buds of the more terminal 

 shoots, in crevices at the crotches of limbs, and under scales 

 of the bark. The eggs hatch about the time the young 

 leaves appear, and the small, green plantlice begin to feed 

 upon the unfolding foliage. These early individuals soon 

 produce living young, the latter shortly attaining maturity, 

 devoloping wings and flying to other trees. This species is 

 most easily recognized by the oval, yellowish green or 

 brown body. There may be four or five generations in the 

 latitude of Washington, and by early July the trees are de- 

 serted for the grains, grasses or other host plants, a return 

 migration to the apple occuring in the fall. 



The green apple aphis°, like the preceding, passes the 

 winter as black eggs. The plant louse has a pear-shaped, 

 yellowish green, green or dark green body instead of the 

 oval form of the European grain aphis. The eggs hatch a 

 little later than those of the preceding species. This plant 

 louse frequently causes serious curling of tlie foliage. It 

 may occur upon the trees throughout the season, and in New 

 Jersey, at least, may produce six generations. 



The rosy apple aphis** is distinguished from the preced- 

 ing by its larger size, rounder shape and usually rosy color, 

 though this latter may vary from salmon to tan or even to 

 slaty gray or black, the body being dusted with white. 

 This aphid also winters as eggs deposited on the trimk and 

 larger limbs. The young plantlice appear with the unfold- 

 ing of the leaves. There are about three generations be- 

 fore the trees are deserted for an unknown food plant. 



Climatic conditions, it is evident to the most casual ob- 

 server, must have a profound influence upon nearly help- 

 less insects like plantlice, feeding almost unprotected upon 

 the foliage of various trees. This is well substantiated by 

 the experience of recent years. The remarkable abundance 



*Siphocoryne avenae Fabr. 

 °Aphis mali Fabr. 

 **Aphis malifoliae Fitch. 



