U. S. D. A., B. E. Bul. 96, Part VI. T. C. & S. P. I. I., October 17, 1912. 
PAPERS ON INSECTS AFFECTING STORED PRODUCTS. 
THE COWPEA WEEVIL. 
(Pachymerus chinensis 1.) 
By F. H. CHitrrenpDen, Sc. D., 
In Charge of Truck Crop and Stored Product Insect Investigations. 
INTRODUCTION. 
The seed of cowpeas are subject to the attack of several species of 
beetles, of which the cowpea weevil (Pachymerus chinensis L.) and 
the four-spotted bean weevil (?. quadrimaculatus Fab.) appear to 
be specific enemies, injuring the seed in much the same manner as 
does the common bean weevil. Like that species they begin opera- 
tions in the field, and continue to breed for successive generations in 
the stored seed until they entirely spoil it for food and seriously im- 
pair its germinating power. Both species are generally distributed 
and injurious in the South, and are widening their range with the 
increasing use of their food plant as a soil renovator and as forage. 
The cowpea weevil resembles the four-spotted bean weevil super- 
ficially in appearance, as in habit, but these two species differ to some 
extent in various details of their life economy, as well as in structure 
and distribution. They belong to the same genus of the family 
Lariide (Bruchide). 
DESCRIPTIVE. 
THE GENUS PACHYMERUS LATREILLE, 
The genus Pachymerus, as defined by Allard, includes species hav- 
ing the following characteristics: ; 
Posterior femora much thickened, armed on the underside near the extremity 
_ with small unequal teeth, and the tibiz, slender and curved. 
The following is Scheenherr’s definition: 
Antenne somewhat longer than the thorax, becoming wider toward the apex, 
compressed; joints subperfoliate, half as long as body, last six to eight joints 
acutely serrate. Head carinate. Eyes sublateral, deeply emarginate, prominent. 
Thorax in front strongly coarctate, slightly narrower than head; behind deeply 
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