25 



monly found on the trunk and roots in summer are the wingless, 

 agamic females. They give birth to living young, and continue to do 

 so, possibly for several years. In spring some of the root-lice will 

 crawl up the trunk and continue to breed there till fall. The colonies 

 of lice on the trunk give rise to winged and migratory females. These, 

 when they locate, give bii-th to wingless male and female lice, and each 

 female deposits a single winter egg in a crevice of the bark. This egg 

 will, in the spring, hatch into a female which will start a new colony 

 of wingless lice on the trunk. Some of these will, in the summer, 

 crawl down upon the roots and continue to breed there. In the north 

 the colonies on the trunk are apt to be killed out by the severe cold 

 weather, but in warmer latitudes man}" of them live through the winter, 

 particularljr if they are pi'otected by a piece of bark. 



THE BLACK PEACH APHIS. 



{Aphis persicie-niger E. F. Smith — fig. 16.) 



This insect, like the woolly apple aphis, does its great injury under- 

 ground. Its ravages on the roots of peach give a sickly appearance to 

 the foliage of the affected tree, the leaves often being light green or 



FIG. 16.— Aphii persicx-niger; winged specimen. (J. B. Smith.) 



vellowish in color, and their edges somewhat rolled. The wingless 

 lice on the roots are of a dark-brown color. They breed there con- 

 tinuously without producing males or eggs. Early in the spring some 

 of the root-lice crawl up the trunk of the tree and locate on the young 

 twigs Here the winged form develops and migrates to other trees to 

 found other colonies. The winged insect is' of a shining black or very 

 dark brown color, the tibia, of the legs being mostly yellowish. 



