58 



MANUAL OF VEGErABLE-GAIWEN INSECTS 



Fig. 41. — The l)eaii 

 weevil ( X 9) . 



dark brown, gray and black, arranged in narrow longitudinal 

 stripes. On the middle of each wing-cover near the inner 

 margin is a fairly distinct light gray longitudinal bar. The 

 exposed tip of the abdomen, the base and last segment of the 

 antennpe and the legs, except the hind femora below, are dull 

 reddish brown. The hind femur is armed 

 on the underside near the tip with one large 

 and two small teeth. The beetles appear 

 in the field about the time the beans are in 

 blossom and feed slightly on the surface of 

 the leaves. In cool weather the beetles are 

 sluggish, but in bright warm days they can 

 take wing quickly and fly to a considerable 

 distance. As soon as the pods become 

 nearly full-grown but while they are still 

 green, the females begin egg-laying. The female first gnaws a 

 slit through the pod close to the ventral suture and by means 

 of her extensile ovipositor then deposits a cluster of eggs on the 

 inside of the pod. The hole made by the beetle in the pod does 

 not heal over but persists as a discolored spot even in the 

 dried pod. The egg (Fig. 42) is translucent 

 white, elongate-ovate, and about -^ inch in 

 length ; the surface is slightly roughened. The 

 eggs are sometimes inserted through an opening 

 in the pod where it has been injured or where it 

 has split in drying. The time required for the 

 hatching of the eggs varies considerably with the 

 temperature but apparently has not been ac- 

 curately determined for eggs laid in fresh pods. 

 On hatching, the young larva bears little resemblance to the 

 mature grub. It is white, the head yellow, the mouth-parts 

 brown and the eyes black. Three pairs of distinct, slender 

 functional legs are present and the body is clothed with long 

 hairs which serve to keep the larva upright when crawling. 



Fig. 42. — Egg 

 of the bean 

 weevil (X 40). 



