152 



INSECTS AFFECTING SHADE TREES. 



usually attempting to conceal themselves on the other 

 side of the branch. At such times they also have a 

 curious habit of waving their long hind-legs in the 

 air, probably for the purpose of frightening away 

 predaceous or parasitic enemies. 



Fig. 79. White Pine Aphis: winged male. Magnified. 



The oviparous female is represented, much mag- 

 nified, at Fig. 78. It is nearly one-fifth of an inch 

 long, shining black, more or less tinged with brown, 

 and ornamented with spots and stripes of white. 

 The wingless viviparous females do not differ essen- 

 tially from this form. The winged male (Fig. 79) 

 is about one eighth of an inch lone:, with a wine: ex- 

 pause of a quarter of an inch. It is blackish, with 

 a slight glaucous bloom, and a whitish longitudinal 

 line along the middle of the back. The wings are 

 subhyaline, with the veins dark-brown, and the 

 stigma almost black. The antennas and legs are 

 quite hairy. 



