THE COWPEA CURCULIO. 



139 



dorsal suture, evidently at the place where the pod is thinnest. So 

 regularly are they made that a badly infested pod will show a dis- 

 tinct row of the punctures running along each 

 side of this suture. A few punctures are also 

 made on the ventral side of the pod in about 

 the same relation to the ventral suture. Thus 

 the egg lies on the upper surface not far from 

 the hilum, or well down on the side (fig. 68, 

 a, b, d). 



Very shortly after the beetle leaves the egg 

 the puncture fills with sap and in from twenty- 

 four to forty-eight hours a tough callous has 

 formed over the opening. In a ripe pod the 

 wound shows as a dark, slightly elevated, and 

 somewhat roughened transverse ridge. 



For purposes of oviposition the pods are not 

 attacked until the peas within them have 

 reached nearly or quite full size. No pods are 

 oviposited in after they begin to become dry 

 and leathery. 



Cloudy cool days or the cooler parts of 

 bright days are chosen by the beetles for ovi- 

 position and feeding. During a slow rain they 

 are very abundant and active. During the 

 hotter parts of the day they remain motion- 

 less in the axils of the plant or buried in the 

 loose earth surrounding the stem. 



At Orlando, Fla., in 1907, Mr. H. M. Russell, 

 of this Bureau, made some records of the 

 number of eggs deposited by a single female, 

 record of these experiments. 



On July 6 the following experiments were made to determine the number of eggs 

 a female would lay: 



A. A male and female were put together in a box of cowpeas. 



B. A male and female were put together in a box of cowpeas. 

 July 8 A laid 26 eggs; B laid 36 eggs. 



10 A laid 26 eggs; B laid 17 eggs. 

 12 A laid 42 eggs; B laid 20 eggs. 

 15 A laid 15 eggs; B laid 13 eggs. 



17 A laid 6 eggs; B laid 7 eggs. 



18 the A beetles escaped; B laid eggs. 

 22 B laid 22 eggs. 



27 B laid 18 eggs. 

 August 3 the B beetles died. 

 A laid 115 eggs in 10 days. 

 B laid 130 eggs in 19 days. 



Fig. 68.— The cowpea curcu- 

 lio: a, Cowpea pod, showing 

 work of adults; b, d, "pea," 

 showing work of larva?; c, 

 eggs, a, Reduced; b, c, d, 

 about natural size. (Origi- 

 nal.) 



I quote from the 



