PULSE CROP PROJECTS 



257 



11. Combating insects and diseases. — Legumes suffer 

 damage from sucking insects such as aphids, or caterpillars 

 which feed on the vines. Weevils working in seeds in the field, 

 or in storage, annually 

 cause tremendous losses 

 to crops of beans and 

 peas. 



The bean weevil is very 

 destructive in the warmer 

 climates, but does not 

 seem to be so harmful in 

 the more northern areas. 

 The adult, a mottled 

 beetle, places its eggs 

 within the pod and from 

 these young larvae hatch 

 and work into the bean, 

 and eat out a sizable 

 cell in which the grub 

 matures. The insect com- 

 pletes its transformation in the seed, and then escapes through 

 a small round hole in the shell, and deposits eggs for another 

 generation of the pests. Several broods may occur, and, if the 

 beans are left undisturbed, they are soon reduced to a powdery 

 condition. Weevil beans are unfit for seed, for even if only slightly 

 injured, the plants which germinate are sickly or the beans may 

 carry the weevils to the field in this manner. They may be con- 

 trolled by fumigation. 



Anthracnose or pod spot is one of the most serious diseases of 

 the bean, often causing enormous losses. The symptoms are 

 most noticeable upon the pods, where the disease appears as 

 sunken, dark-colored spots. Similar spots may be found upon 

 the stems and leaves. Anthracnose is most commonly spread 



FiQ. 67. — Bean weevil and injury to stored 

 beans. 



