62 BEAN CULTURE 



until the seed is useless for planting or as food for 

 man or stock. In southern sections and even as far 

 north as Washington, D. C., it is almost impossible 

 to obtain a crop of beans uninfested by bean weevil, 

 and hence the stores in the southern cities are sup- 

 plied mainly from the north. The bean weevil varies 

 in size but its length will average about an eighth of 

 an inch. The wing covers are mottled and the insect 

 is thickly coated with fine brown, gray and olive 

 pubescence. F. H. Chittenden* says that oviposition 

 takes place primarily in the field, eggs being depos- 

 ited upon or inserted in the pod through the hole 

 made by the jaws of the females and other openings 

 such as are caused by drying and splitting. In 

 shelled beans the eggs are dropped loosely in the 

 bag or other receptacle in which they are stored or 

 are placed in holes made by the weevils in their exit 

 from the seed. Less seldom they are attached to the 

 outer surface of the seed. Unlike the pea weevil, a 

 large number of individuals will develop in a bean, 

 as many as 28 having been found within a single 

 seed. Beetles begin to issue from the beans in a cli- 

 mate like that of the District of Columbia as early as 

 October. The beetle is shown in Fig. 16. 



Treatment. No satisfactory preventive of the 

 bean weevil in the field has yet been found. Atten- 

 tion must, therefore, be directed to destroy the in- 

 sects in the dry seed. The only thing to do is to re- 

 sort to fumigation or heat. The earlier the seed is 

 treated after being gathered, the better will be the 

 results. Just before planting, seed infested should 

 be lightly thrown into water. The injured seed will 



*U S Year Book dept agri, 1898. 



