THE COWPEA CUKCULIO. 



133 



base of the thorax anteriorly and three times as long as the latter, the shoulder obtuse^ 

 somewhat rounded; lateral margins straight, toward the apex very slightly narrowed, 

 the apex itself taken together obtusely rounded, convex above, obscurely bronze* 

 somewhat polished, with rows of deep, round, excavated pits, the even surface between 

 minutely punctulate; femora moderately clavate, below and behind the middle 

 armed with acute robust teeth; tibise compressed, somewhat bowed, with teeth 

 obsolete; tarsi elongate, with yellow pads below. 



FEEDING HABITS. 



Feeding punctures made by both males and females in cowpea pods 

 can not be outwardly distinguished from the egg punctures. They 

 are made in the same places on the pod and by the same methods, 

 some of the beetles even going so far as to enlarge the cavity at the 

 bottom of the excavation, probably because they prefer the tissue 

 of the peas themselves to that of the pods as food. If either a 

 feeding puncture or an egg puncture reaches and penetrates a pea 

 it causes an abnormal development of the kernel even though no 

 larva develops. The pea becomes gnarled, one-sided, and light in 



» d 



Fig. 67.— The cowpea curculio ( Chalcodermus xneus): a, Adult; 6, larva; c, head 

 of same; d, pupa, a, b, d, Enlarged; c. more enlarged. (From Chittenden.) 



weight and will be lost in the threshing or winnowing. The damage 

 caused by the feeding operations of the adult beetles on cowpeas is 

 not serious. 



As the waiter has not had opportunity to observe the work of the 

 beetles on cotton the following description of such injury is quoted 

 from Prof. Wilmon Newell as it occurred in Georgia in 1904: 



Injury by this species was personally investigated at Herod, near Dawson, Ga., May 

 27, 1904. Beetles were found upon about 15 acres of cotton, from 4 to 10 beetles on each 

 plant. The plants were about 4 inches high. The beetles feed for the most part in 

 the afternoon or early morning and upon cloudy days, although a few may be found 

 on the plants at noon on bright days. The beetle punctures the tender stem, often 

 just below a leaf, and this puncture reaches to the very center of the stem or occa- 

 sionally to the epidermis of the opposite side. Punctures occur upon leaf stems and 

 the upper tender part of the main stem near the ground . The punctures upon leaf stems 

 are so close as to practically sever the stem; thejeaf soon withers and dies and drops. 

 In some cases the beetles seem to stay over the puncture after it is made and suck up 

 the sap which accumulates. In several cases we found a beetle upon the shady side 

 53518°— Bull. 85, pt 8—10 2 



