INJURING THE LEAVES. 



201 



plants, including turnip, radish, Field Cress, and 

 Shepherd's Purse. It appears to 

 have been originally an European 

 species, and was probably intro- 

 duced into America at an early 

 date. It is probable that it is now 

 found in this country wherever 

 the cabbage is extensively grown. 

 The Cabbage Aphis is a small, 



^ovTparous^afe^ 131 greenish insect, generally covered 

 Magnified. with a w hiti s h, mealy coating, that 



occurs in great numbers on the leaves and in the 



heads. During the summer months it reproduces 



Fig. 108. Cabbage Aphis : male, magnified. 



viviparously, but in autumn true males (Fig. 108) 

 and females (Fig. 107) are developed, eggs being- 

 deposited by the latter upon the cabbage leaves. 



Remedies. — Kerosene emulsion is the most effec- 

 tive insecticide that can be used against this insect. 



