50 



first-named species is met with in cowpeas much less frequently than 

 the last two. 



The species breeding in the cowpeas which served as check samples 

 to the series kept in cold storage were the cowpea weevil and the four- 

 spotted bean weevil. The principal food of these two species is the 

 cowpea, and the}^ are found in most countries where cow]:)eas are 

 grown. The first eggs are usually deposited in the field, but the 

 greatest damage is generally done after the seed is stored. The 

 beetles continue to develop in the dried and stored seed for several 

 generations. Under favorable conditions, depending chiefly on the 

 temperature, six or seven broods may develop Avithin a year, according 

 to Doctor Chittenden's observations. If not checked their ravages 

 continue until the cowpeas are unfit for any practical purpose, not 

 even serving for the sustenance of the weevils. Plate II, fig. 1, shows 

 cowpeas which have been destroyed in this way. 



CONDITIONS AND RESULTS OF EXPERI^VIENTS. 



The experiments herein discussed were conducted with Clay cowpeas 

 grown in Georgia in 1902. A germination test made of the bulk lot 

 in February, 1903, showed a vitality of 83.5 per cent. 



March 7, 1903, duplicate sets of twelve lots each, put up in cloth 

 bags, Avere stored in " trade conditions," and in cold storage at AVash- 

 ington, D. C, Richmond, Va., Jacksonville, Fla., and New Orleans, 

 La. At each of these places the " trade conditions " Avere represented 

 by seed Avarehouses. The cold-storage samples Avere subjected to a 

 temperature of 32° to 31° F. The remainder of the original bulk 

 Avas kept in the seed laboratory at a temperature varying from 55° to 

 80° F. Samples from the entire series Avere tested from time to time 

 for o-erinination. The results of the tests are given in Table I. 



Table I. — Pcrccntof/r of (imninatioii of cfxr/j'f/.s' stored at rarioiis jilaco! under 

 "■trade conditionK" and in cold storafie on March 7. 1903, and returned from 

 storage at rarious dates. 



" The dates given are approximate only, varying slightly from actual dates of return of 

 seeds from storage. (Jermiuation tests in all cases were made within a very few days 

 after return of seeds from storage. 



''The original liulk sample germinated 83.."> per cent in February, 1003. 



«• Destroyed by weevils. 



" Many destroyed by weevils. 



