THE MONTHLY BULLETIN. 



59 



Fig. 47. — The Monterey pine louse, Essigella calif ornica (Essig). A, winged 

 female; B, nymph of the winged female; C, apterous female. (Essig, P. C. Jr. Bnt.) 



THE CABBAGE LOUSE. 



Aphis brassicw Linn. 



(Fig. 48.) 



General Appearance. — Dark greenish yellow to brownish, with dark 

 transverse bands across the abdomens of some individuals. All covered 

 with a fine white powder, which gives them a silvery or frosted appear- 

 ance. 



Life History. — The lice appear with the first plants in the spring and 

 increase with such rapidity as to soon almost entirely cover the host. 

 This condition prevails throughout the early summer, after which the 

 parasites begin to reduce their numbers. It is a disgusting pest on 

 cabbage, cauliflower and brussels sprouts. 



