49 



COLD STORAGE FOR COWPEAS.«^ 



By J. W. T. DuvEL, Seed Laboratory, Bureau of Plant Industry. 



INTRODUCTION. 



The value of cowpeas for the improvement of the soil as well as 

 for forage has long been recognized. In recent j^ears the area on 

 which cowpeas are grown has been greatly extended. With the in- 

 creased acreage there has been a more widespread distribution of the 

 weevils destructive to cowpeas. Large quantities of seed are destro^^ed 

 annually in this way, entailing a great loss to seedsmen. 



Carefully conducted experiments, extending over a period of nearly 

 two years, have shown that cowpeas can be kept free from weevils if 

 stored at a temperature of 32° to 3-1° F. It is understood that this 

 method is practiced to a limited extent by a few seedsmen, who find it 



Fig. 17. — a, Bruchus ohtectus ; h, B. chinensis ; c, B. qtiadrimaculatus — all 



(after Chittenden). 



much enlarged 



ir- 



far more satisfactory than the methods of fumigation which have 

 been so generally used. 



WEEVILS INFESTING COWPEAS.*^ 



There are three kinds of weevils which do considerable damage to 

 cowpeas during storage — the common bean weevil (Bruchus obteetvs 

 Say), the' cowpea weevil {BrucJms chinensis Linn.), and the four- 

 spotted bean weevil {Bruchus (jiiadrimacidatus Fab.). The adult 

 beetle of each of these species is shown in figure 17, <2, &, and c. The 



a What is here said concerning the storage of cowpeas applies equally well to 

 garden peas and beans, and presumably to other seeds of a similar character 

 which are attacked by weevils. 



6 The notes on the ravages and life history of these weevils are based on Dr. 

 F. H. Chittenden's " Insects injurious to beans and peas," Yearbook United 

 States Department of Agricultur.? for 1898, pp. 233-260. Plgure 17 is taken from 

 the same paper. 



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