244 INSECTS AFFECTING TRUCK CROPS 



spray for all lice. It should be used, if possible, in a way to hit 

 the insects. 



The Bean Maggot or Bean Fly. These maggots (Pegomya 

 sp.) are about one-fourth of an inch long when full grown, yellow- 

 ish in color, blunt at one end, tapering at the other. The change 

 to the pupal stage takes place in the ground near the plant injured. 

 In about a week the perfect fly, which closely resembles a house- 

 fly, emerges from the puparium and works its way to the surface 

 of the ground (Fig. 251). 



Injury. This maggot bores in planted beans, and works not 

 only in the seed but in the stem of the growing plant as well, thus 

 causing it to wither and die. 



2 c 



FIG. 252. Bean weevil and pea weevil. (After Brehm.) 



Control. Rotation of crops and fall plowing appear to be the 

 only available remedial measures. 



The Bean Weevil. This is a small robust snout beetle (Bru- 

 chus obtectus Say), brownish gray in color, with head bent at 

 right angles to body. The wing-covers are shorter than the ab- 

 domen.' Eggs are laid on the growing pods in the field, and the 

 grubs enter the young beans, sometimes several in one bean. 

 They continue their work in dry beans, rendering the same unfit 

 for seed. This insect also attacks peas and occasionally other 

 seeds. 



Control. Infested seeds, for the most part, float on the water, 

 while sound seeds sink. This affords a means of separating good 

 from bad seed. A still better method is fumigation of the seed 

 with bisulfid of carbon. Place the seed in a tight receptacle, 



