Weevils in Beans and Peas. 9 
in the field. As each generation of weevils reduces the value of 
seeds for planting and for food, steps should be taken to kill, at 
harvest time, such grubs as may be in the seeds and thus. prevent. 
further losses. If this is not done the seeds become honeycombed 
by the feeding of generations of grubs and may be reduced to a 
powder. (Fig. 8.) Because bean and cowpea weevils can breed 
in dried seeds it is important not to store uninfested seeds near seeds 
that are infested, for the weevils spread rapidly and will soon infest 
the newer seed. 
Fic. 6.—In escaping from beans, peas, or cowpeas, or any host, weevils leave behind 
them the small round holes familiar to all. In making these holes they use their jaws 
to cut around the dark spots shown in Figure 5 and then push away the circular flap 
of skin just as one opens a tin can of preserved fruit with a can opener. These cir- 
cular bits of. skin, shown above, about 4 times natural size, may be found among the 
seeds. : 
THERE ARE DIFFERENT KINDS OF WEEVILS. 
Injury to leguminous crops is caused by more than one insect. 
Those considered in this bulletin are the pea weevil,’ the common 
bean weevil,? the cowpea weevil,’ the four-spotted bean weevil,* the 
broad-bean weevil,® the lentil weevil,® and the Mexican bean weevil.? 
These are all commonly found in supphes of beans, peas, cowpeas, or 
lentils in this country. Other species are sometimes found in im- 
ported seeds, but will not be discussed here. 
1Bruchus pisorum Linnaeus. 
2B. obtectus Say. 
8B. chinensis Linnaeus. 
4B. quadrimaculatus Fabricius. 
5B. rufimanus Boheman. °° B. lentis Boheman. *Spermophagus pectoralis Say. 
101921 °—22——_9 
