156 FRUIT INSECTS 



sometimes at the rate of two to twenty a day for two or more 

 weeks. The baby aphids or nymphs are usually born enwrapped 

 in a thin pellicle, which is soon cast off. The little creature 

 begins to suck its food through a beak longer than its body, 

 and its waxy coating is secreted in a few hours. As these little 

 nymphs feed and grow their skin is shed four times, a new waxy 

 coating being secreted each time, and they may become full- 

 grown in from eight to twenty days. Many of these wingless, 

 agamic nymphs persist on the roots, and some of them even on 

 the tree above ground, all the year through even in New York 

 state and other cold northern latitudes. These aphids mostly, 

 if not wholly, cease breeding, however, even in southern localities 

 during the winter months. During the autumn months, some- 

 times beginning in August, there is developed both above and 

 below ground many minute, winged, greenish-brown-bodied, 

 agamic female aphids with the body more or less covered with 

 the woolly secretion. These winged forms may fly or be blown 

 to near-by elm trees. They are destined to play an interesting 

 and important role in the perpetuation of their kind. In a few 

 days these winged, agamic migrating forms give birth to from 

 six to twelve young, about half males and half females. Both 

 sexes are wingless and do not grow after being born, having no 

 mouth parts with which to take food. The reddish-yellow 

 females are about one-twentieth of an inch in length and twice 

 as large as the slenderer, olive-yellow males. A few days after 

 mating the female lays a single long, dark, cinnamon-colored 

 oval egg nearly as large as her body in a crevice of the elm bark. 

 Some of these eggs have been found in crevices of the apple 

 bark where there had been colonies of the lice during the sum- 

 mer; others record them as laid on the bark on the crown of 

 the tree near the roots, but as a rule they are laid on the elm. 

 These winter eggs hatch in early spring and the stem-mothers, 

 as the first brood of lice are called, are found on the opening^ 

 elm leaf buds. They are wingless, and feed on the under surface 



