204 INSECTS AFFECTING VEGETATION 



dantly pitted. Damage is caused by cowpeas by punctures made in 

 the pods and peas by the adults for the purpose of feeding and ovi- 

 position and by the feeding of the larvae within the maturing peas. 

 The damage, though seemingly widespread, is not very evident, as 

 it affects the value of the crop only where the peas are grown for 

 seed. More serious injury is done by this species in early spring to 

 young cotton, which it is forced to use for food. Individual cotton 

 plants or the entire stand in a field may be injured or completely 

 destroyed. 



The distribution of this weevil probably coincides with that of 

 the cowpea, but since the injury to cotton is more noticeable it has 

 seldom been reported from beyond the cotton belt. It is, without 

 much doubt, of southern origin and has probably spread northward 

 following the introduction and use of the cowpea. In the spring 

 cotton is often damaged seriously while it is small by the adult 

 beetles, but as this trouble occurs only on land on which cowpeas 

 were grown the preceding year it is apparent that cotton is a food 

 plant from necessity rather than from choice. Later in the season 

 beetles in confinement have starved to death rather than feed on 

 nearby young cotton. 



When full grown, the larva cuts a hole to the outside of the pea 

 and then through the pod and drops to the ground. The opening in 

 the pod is frequently at some distance from the injured pea. It is 

 quite regular, circular in outline, about 2 mm. in diameter, and the 

 disk which is cut out often remains hinged at one side. After drop- 

 ping to the ground the larva immediately begins to burrow into the 

 earth. The larger and more active grubs burrow deeper and more 

 rapidly. After reaching the necessary depth, the larva by the mo- 

 tion of its body proceeds to form an oval cavity somewhat larger 

 than itself. It spins no cocoon whatever. After entering the ground 

 the larvae do not pupate at once, but remain quiescent for several 

 days in the earthen cells. 



The cowpea curculio passes the winter in the adult stage, going 

 into hibernation when its food supply is destroyed in the fall with 

 the first severe frosts. The beetles winter, hidden under rubbish or 

 lumps of earth or buried from 1 to 3 inches deep in the earth itself. 

 The beetles emerge from hibernation as soon as the weather fairly 

 warms up. 



In so far as cotton is concerned, the sovereign remedy would 

 seem to be to refrain from planting it on land previously occupied 

 by cowpeas infested with this pest. Planting cowpeas with the cot- 

 ton would probably cause the beetles to confine their attentions to 

 the former plant. The larvae, as a rule, do not emerge from^the pod 

 until the pods are well ripened. If therefore the crop is being 

 grown for seed the pods may be gathered frequently as they ripen. 

 If stored in a tight, dry bin the larvae as they emerge will be unable 

 to complete their development. (Bui. 85, Part VIII, U. S. D. A. 

 B. E.) 



The Smoky Crane-Fly. The maggots or larvae of the Tipulidse 

 are known in the several parts of this country by many local names, 



