The Bean 237 



bean straw or manure on nncontaminated soil. Long rotations 

 and shallow cultivation are desirable. IJxperimental breeding 

 promises to yield commercial strains resistant to the fusarium. 



Bean weevil (Bruohus oMectm). — This is a small light- « 

 brown beetle, having the wing-covers about % in. in length, 

 mottled with light brown, gray and black. The eggs are laid 

 in the pods in the field and the grubs develop in the seeds 

 and transform to beetles within cavities just under the integu- 

 ment. Ii; emerging the beetle cuts out a circular lid in the 

 seed-coat. Several beetles may develop within a single seed. 

 The number of generations that may develop annually in the 

 field depends on the temperature and length of the season. 

 In the North there is only one brood but in the South there 

 may be six or more. In storage, breeding may be continuous 

 if the temperature is sufficiently high and the beans may be 

 reduced to a powdery mass. Control: Weevils in the beans 

 may be killed by fumigating with carbon bisulfide at the 

 rate of about 1 ounce to each bushel of seed. A container as 

 near air-tight as possible should be used and the fumigation 

 continued for twenty-four to thirty-six hours. It is not advis- 

 able to use weevil-infested beans for seed since the germina- 

 tion is poor, and weak plants are produced. 



Bean leaf-beetle (Ceratoma trifurcata) . — This small beetle, 

 about . % in. in length, is yellowish to reddish and has the 

 wing-covers marked with six black spots. The beetles feed on 

 the underside of the leaves and riddle the foliage with holes. 

 The eggs are laid on the ground at the base of the plants and 

 the grubs attack the roots. From one to three broods occur 

 annually, depending on the length of the season. Control: 

 Spray the plants with arsenate of lead, 4 pounds of paste or 

 2 pounds of powder, at the first appearance . of the beetles, 

 taking care to hit both the under surface and the upper sur- 

 face of the plants. 



Bean ladybied (Epilachna corrupta). — In the semi-arid 

 regions of the Southwest this ladybird beetle is a serious 

 enemy of beans. It is yellowish to brownish orange, about 

 % in. in length, and has the wing-covers marked with 16 small 



