CLASSIFICATION AND DESCRIPTION OF COMMON INSECTS 319 



Larva. — -Like white grubs; live in decaying wood. 

 Pupa. — -In an oval cocoon made of fragments of wood. 



BRUCHID.S (PEA AND BEAN WEEVILS) 



Pea Weevil (Bruchus pisorum Linn.). Adult. — A small brownish 

 black beetle, l^ inch long, with characteristic black and white 

 markings; sides of thorax notched; abdomen 

 projects beyond the wing-covers. Two black 

 spots on micovered portion of abdomen; an- 

 tennae ii-jointed; hind femora thickened and 

 prolegs with two spines. A native of the old 

 world (Fig. 208). 



Eggs. — Yellow, 3'^o inch long, spindle-shaped. 



Larva. — White fleshy wrinkled grub, about 

 3-^ inch long when fully grown; 3 pairs of 

 minute legs. 



Pupa. — White, becoming brown after thresh- 

 ing or fumigating; thorax with notched sides; 

 formed in the pea. 



Life-history. — Adult winters over and eggs 

 are laid on the forming pods. The larva bores 

 through the wall of the pod and enters the seed, 

 where it feeds and grows. The pupal stage 

 lasts about a week. Mature adults develop in 

 August, the majority remaining in the mature 

 seed all winter. Several grubs may inhabit 

 a single seed. 



Control. — Fumigate peas with carbon bisulphide; drench seed with 

 kerosene; store the peas over for a season in tight sacks before planting; 

 raise the temperature to i45°F. to kill the weevils. 



Bean Weevil {Bruchus ohtectus Say) . A dult. — A small brown beetle, 

 about ig inch long, with wing-covers shorter than the body, and 

 "marked with ten impressed and dotted longitudinal lines which are 

 broken up into pale yellow dashes and dark brown spots" (Fletcher); 

 body covered with short silky hairs; tips of abdomen, antennae and legs 

 of a reddish tinge; antennae enlarging toward the tip. Probably a 

 native of Central or South America. 



Fig. 208. — Pea 

 weevil: a, the grub; b, 

 the pupa, under surface; 

 c, the pupa, upper sur- 

 face; d, the adult weevil. 



