24 



LIFE HISTOEY OF THE ALDER BLIGHT APHIS. 



black; the antennae and legs are the color of the body and the tarsi 

 are blackish. The antennse are 6- jointed, rather short, and reach 

 at most to the middle of the mesothorax. Antennal joints 3 and 6 

 are longest and subequal in length, each being about as long as joints 

 4 and 5 combined ; joints 1, 2, 4, and 5 are shortest and subequal in 

 length, with the two basal joints, as usual, stoutest; all of the joints 



Fig. 9. — Colonies of apterous females 

 on alder. (Original.) 



.^^^ 



f^V 



H 



,f1 



^:*^'vr 



Fig. 10. — Colonies of 

 apterous females on 

 alder. (Original.) 



are provided with a few fine and short hairs. The tail and last 

 abdominal segment are as in the migrant. Length about 3 mm. 



HIBERNATING SERIES. 



The hibernating larvae, as well as those deposited by migrants and 

 apterous females, are of an orange color, with the eyes and tarsi dark 

 brown or black; all of them are covered with a short and shaggy 

 secretion. The antennse are 4- jointed in all of them; they are 

 short, as usual, and reach to nearly the middle of the mesothorax. 



