Vegetable Plant Lice 



Reproduction on the pea is rapid, and soon enough lice are pres- 

 ent to sap the vitality of the plant, and the farmer finds that his peas 

 are lousy and certain to give a greatly reduced crop if any at all. 



By midsummer the pea crop is off and such of the lice as could 

 not develop wings and escape, perish. The contant production of 

 winged forms and their more or less constant movement lead to in- 

 festation of late peas when they are grown. 



Throughout the season, breeding continues on clovers, and 

 sometimes serious damage is done to that crop. 



Late in the fall the winged forms, which may have been devel- 

 oped on vegetable crops, make their way back to clover and vetch, 

 true males and females are produced and the over-wintering eggs 

 laid. 



Fig-. 4 



Cabbage Aphis 



i — Adult winged female; 2 — Immature female; 3 — Adult wing- 

 less female 



Bean Louse 



(Aphis rumicis Linn.) 

 The species was taken on bean abundantly in the summer of 

 1916, but has not since been noted. 



Cabbage Aphis 



(Aphis brassicae Linn.) 

 The cabbage louse is a small green insect. Its body is apparent- 

 ly covered with a mealy powder. 



