FIELD CROP INSECTS 261 



four or five generations a year. The larva is a footless white 

 grub with a brown head and feeds entirely within the squares 

 or bolls. Many squares are destroyed by the feeding 

 punctures of the adult weevils. The squares are preferred 

 both for food and egg-laying, but in late summer and fall, 

 as they all become infested, the bolls are attacked, as many 

 as fifteen larvae having been found in a single boll. With the 

 first killing frosts the adult weevils go into hibernating 

 quarters. In seeking places for hibernation the weevils fly 

 from field to field, and it is at this season that the principal 

 migration takes place. They may hibernate in hedges, 



FIG. 184. The cotton boll weevil, natural size, showing variatioaSn 

 size and color. 



woods, corn-fields, haystacks or farm buildings, particularly 

 about seed houses or similar situations. Others crawl into 

 cracks in the soil in cotton fields, under grass, into Spanish 

 moss on trees, weeds or trash, into empty cotton burrs, and 

 in the more southern sections may hibernate in the injured 

 bolls. 



By far the most important measure in the control of the 

 boll weevil is the destruction of the plants in the fall as soon 

 as the cotton can be picked. This both destroys the weevils 

 and prevents their increase. The stalks should be plowed 

 out and burned as soon as possible. It is well to plow out 

 all but a row here and there upon which the weevils will 



