INSECTS INJURIOUS TO BEANS AND PEAS 



309 



The Common Bean-weevil * 



Throughout the United States the common Bean-weevil is the 

 principal enemy of the bean. The small, white, footless grubs 

 feed within the beans, both in the field and in storage, and trans- 

 form to the common brown-gray weevils which infest white beans. 

 In the South its attacks are so serious that it is almost impossible 

 to secure a crop uninfested, so that most of the beans both for 

 seed and consumption come from the North. Not until 1870 did 

 injury by this insect attract attention in the United States, but 

 now it occurs throughout our borders and is practically cosmopol- 



FIG. 223. The common bean-weevil (Bruchus obtectus Say): a, beetle; b, 

 larva; c, pupa all greatly enlarged. (After Chittenden, U. S. D. Agr.) 



itan in its distribution. It is probably a native of Central or 

 South America. 



The adult weevil is about one-eighth of an inch long and is cov- 

 ered with a fine brown-gray or olive pubescence, giving it that 

 color, while the wing-covers are mottled as shown in Fig. 223, a. It 

 may be distinguished from the pea-weevil by its longer thorax and 

 by the two small teeth next to the large tooth at the tip of the 

 thighs. 



Life History. In the field the eggs are laid upon or are inserted 

 in the bean-pod through holes made by the female or such open- 



* Bruchus obtectus Say. Family Bruchidce. 



