THE COWPEA CURCULIO. 143 



ground than are many members of the family. They frequently are 

 coated with mud, and when so protected become almost invisible 

 when on the ground. After dropping they often lie twenty minutes 

 before making the slightest motion. 



It requires, then, something over a month for the generation to 

 develop, allowing 6 days to the egg, 9 days to the larva in the pod, 

 and 6 in the ground, and 1 1 days to the pupa. 



SEASONAL HISTORY. 



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. In the vicinity of Clemson College, S. C, 

 this occurs in the latter part of October or early November. 



No out-of-door records as to the exact place of hibernation have 

 been made, but an experiment carried on in the greenhouse will indi- 

 cate the probabilities. In the fall of 1908 some 200 of the beetles 

 were confined by a wire-screen cage to an area of ground about a 

 yard square, on which were growing cotton and cowpea plants. The 

 beetles were left in this cage, and by the latter part of November had 

 largely disappeared, although the house was kept at summer heat. 



At several different times during the winter examinations were 

 made, and the beetles were found buried in the earth at a depth of 

 from 1 to 3 inches. As late as March 15, 1909, beetles were found in 

 the earth, and on this date one was observed sluggishly climbing a 

 blade of wheat growing near by. The beetles winter, then, 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. The earliest date at which they have been reported in 

 various localities is as follows: Arnaudville, La., April 16, 1908; 

 Coffee County, Ala., May 13, 1904; Stillwater, Okla., May 20, 1909; 

 Benson, N. C, May 24, 1907; Messers, S. C, May 28, 1909; south- 

 eastern Missouri, June 15, 1907; Monetta, S. C., June 17, 1908; 

 Orlando, Fla., July 6, 1907. These are not, of course, the dates at 

 which the beetles emerged from hibernation, but indicate that they 

 were active at least by these dates. 



Coming out in the spring hungry, they are willing to attack young 

 cotton and probably other fresh plant growth as it appears. It is a 

 very general custom to follow cowpeas with cotton in the rotation, 

 and in every case where damage to young cotton has been reported it 

 has been on a field planted to cowpeas the preceding year. 



The beetles, feeding on cotton, cowpeas, and other young plants, 

 exist until the cowpea pods become of sufficient size to permit ovi- 

 position. This date varies greatly with the season. In 1908 half- 

 grown larvse were found on August 1 , showing that eggs had been 



