104 INSECTS INJURIOUS TO VEGETABLES 



Any single indoor generation is capable of exhausting seed and 

 completely ruining it for food or planting or any other practical 

 purpose. The beetles begin to issue in the field in a climate like 

 that of the District of Columbia as early as October, when in 

 the natural course of events the eggs for a new brood would 

 be deposited in such pods as had cracked open so as to expose 

 the seeds within. This beetle prefers the bean as a host plant, 

 but it will also breed in cowpeas in the field as well as in store, 

 and in confinement develops in dried peas, lentils, and chick- 

 peas. It is no more true of seed infested by this species than 

 of that attacked by the pea weevil that germination is not im- 

 paired by the work of the weevil in the bean. Weeviled beans 

 should not be planted. In a test only 50 per cent, of the infested 

 seed used germinated, and only 30 per cent, could have passed 

 the germinating stage, and these, owing to injury to the seed 

 leaves, would probably have produced plants of low vigor and 

 correspondingly low productiveness. 



Remedies.— From the fact that this species breeds continuously 

 in dried seed, neither the expedient of holding over seed for 

 a year before planting nor that of planting late for seed stock 

 would be productive of good, as in the case of the pea weevil. 

 Recourse must therefore be had to fumigation or to heat, and 

 the earlier the seed is treated after it has been gathered the 

 better the result. Just before it is planted seed infested with 

 this bean weevil should be lightly thrown into water. Badly 

 injured seed will float, and may be picked out or poured 

 off and destroyed. Sound seed only should Ije reserved for 

 planting. 



The Cowpea Weevil (Bnichits chincnsis Linn.). — Cowpeas 

 are quite liable to be infested by the cowpea weevil and the 

 four-spotted bean weevil, which injure its seed in the same 

 manner as the common bean weevil. Like that species they 

 begin work in the field and continue to breed in the stored seed, 



