PLANT LICE INJURING THE FOLIAGE 



201 



If peas are planted far enough apart in rows and the ground is dry, 

 the Uce may be brushed from the vines and killed by following with 



Fig. 250. 



-The Pea Aphis. Adults at work on vine. Original. 



a cultivator between the rows. If the ground is wet, the lice may be 

 brushed into a long, shallow pan. A Uttle water should be poured 

 into the pan and covered with a film of 

 coal oil. 



The Bean Aphis (Aphis rumicis Linn.) 



The tender shoots of beans sometimes are 

 covered with thickly clustered plant lice. 

 The same species is found commonly on pig- 

 weed, dock, and other weeds. The aphis is 

 one tenth of an inch long, black, often with 

 a few whitish dots on each side> the an- 

 tennae are wliitish in their central seg- 

 ments. 



Winter is passed in an egg stage on the 

 twigs of wahoo or of snowball. The lice first 

 migrate to weeds and then to beans. In late summer, they return 

 to the slirubs named. 



Fig. 251.— The Pea Aphis. 

 Adult enlarged and nat- 

 ural size. Original. 



