232 



THE CANADIAN ENTOMOLOGIST 



will show this species to be generally distributed over the country 

 and since it closely resembles Aphis brassica it has likely been 

 mistaken for this species in some instances. 



The fact that the winged viviparous female bears sensoria on 

 segment IV. of the antenna, alone separates it from brassicce. The 

 sexes have not been found and our present knowledge leads us to 

 believe that the more usual means of passing the winter is as 

 viviparous females. 



Wingless viviparous female. (Fig. 21). 



Entire body pale whitish green, head slightly dusky. Abdo- 

 men with a longitudinal row of impressed dots along each side in 



line with the corn- 

 icles; also on each 

 side of the median 

 dorsal line is a row 

 of transverse shin- 

 ing areas with a 

 reticulated surface, 

 those on the last 

 four or five seg- 

 ments usually 

 united; and a sim- 

 ilar row of smaller 

 areas on each side. 

 These shining re- 

 ticulated areas 

 contrast with the 

 rest of the body 

 which is dull and 

 very slightly pul- 

 verulent. Thoracic 

 segments w i t h 

 similiar transverse 

 areas. In specimens 



Fig. 21. — Aphis psetxdobrassicx, wingless viviparous female. 



just molted the entire body appears shining and reticulated. 



Eyes black. Antennae blackish excepting segments I, II and 

 basal half of III which are pale; reaching a little beyond the 



