92 INSECTS AEEECTIXG STOEED PEODUCTS. 
tigations, and the year afterwards 1S gave a more general economic 
account, together with figures and brief descriptions of the egg and 
postembryonic larva. In 1909 Lefroy and Howlett 21 recorded three 
new food plants. 
It is interesting to note that it has been noticed of this weevil that 
material infested by it undergoes marked elevation in temperature, 
particularly at times when the beetles are undergoing transformation 
and issuing from the seed. In one instance, the temperature of a 
small sack of seed infested by the cowpea weevil was found to be 
25° F. higher than the surrounding atmosphere. 
METHODS OF CONTROL. 
General remedies. — The remedies to be employed for the cowpea 
weevil are practically the same as for the bean weevil and the four- 
spotted bean weevil, both of which have the same habit of breeding 
continuously in stored seed. Eemedies are fully discussed under 
" Methods of control " in a previous article on the broad-bean weevil. 
Bisulphid of carbon and hydrocyanic-acid gas fumigation are the 
best. The hot water remedy, dry heat, and the introduction of para- 
sites from localities where these are established, into others where 
they are not known to occur, are all desirable. It should be .added 
that it is impossible to prevent injury in the field or to stamp this 
species out, since it is Jready too well established from Maryland 
southward and westward. 
Holding over the se . ,i, as practiced for the pea and broad-bean 
weevils, is a useless remedy for this species. 
Full directions for the application of dry heat and of hot water, 
and for fumigation with bisulphid of carbon, are given in the article 
on the broad-bean weevil and instructions for fumigation with 
hydrocyanic-acid gas are furnished in Circular 112 of the Bureau of 
Entomology. 
Drying the seed. — Frequent inquiry is made in regard to the con- 
trol of weevils in cowpeas by what is known as "kiln drying," a 
method which is stated by correspondents in the South to be used in 
California. Inquiry of several agents of this bureau who have been 
engaged in work in California fails to elicit the fact that the kiln- 
drying process is used in that State; indeed, we have no specific 
knowledge of the use of this practice in any locality. There is, how- 
ever, a process which is sometimes so termed. It consists of passing 
cowpeas, grain, and other seeds and foodstuffs over heated pipes, or 
passing heated air through them in such a manner as to subject the 
infested material to a temperature of 135° to 110° F.. which is fatal 
to the larvae and adults of the cowpea and other weevils, as it is also 
to their eggs. This process is at present used mainly for grain, espe- 
° Bui. 96, Pt. V, Bur. Ent., U. S. Dept. Agr., pp. 75-SO, 1912. 
