10 BULLETIN 1066, TJ. S. DEPARTMENT OF AGRICULTURE. 



dries and hardens on the ground. 'When the larva is full grown it 

 ceases feeding, assumes a clearer cream color, and, after a period of 

 a week or two of inactivity within the nut, cuts its way out through 

 the shell and enters the ground to a depth of from 2 to 4 inches to 

 pupate. Larvae may be found in the nuts from early in June until 

 late in September. In one lot of 805 larvae which issued from in- 

 fested black walnuts kept in rearing jars the first larva left the nut 

 on July 14 and the last on September 21. These larvae, like those 

 of the butternut curculio, chiefly issued early in the morning and 

 the largest numbers always in cool weather. In small green nuts 

 only one larva matures to the nut, but two or three larvae may de- 

 velop together in a large nut. Apparently where several larvae hatch 

 and begin feeding in a small nut one individual always kills and 

 devours the others. In two or three instances one larva was found 

 killing and eating its fellow. On entering the ground the larva 

 seeks a place where the soil is solid and fashions a smooth-walled 

 cell (PI. IV, G ; PL V, D), where it rests for several days before 

 pupating. 



PUPA. 



The pupa (PL IV, F ; PL V, D) is white and is about 9 mm. long 

 by 3 mm. thick. The abdomen, thorax, and wing pads are covered 

 thinly with short, stiff hairs, these hairs being shortest on the wing 

 pads. The pupa occupies an unlined earthen cell from 2 to 4 inches 

 beneath the surface of the ground. The pupa stage covers a period 

 of from two to three weeks. 



The mature beetle (PL IV, A and B) is dull reddish-brown and 

 covered with grayish pubescence. There is a lighter colored, in- 

 distinct, broad band behind the middle of the elytra and a vague, 

 broken line of the same lighter shade on each side of the thorax. 

 The snout is half as long as the body and the back is ridged and 

 punctured. The length averages from 6 to 7 mm. This beetle in 

 size and general shape resembles very closely the butternut curculio 

 but its color markings and elytral sculpturing are less pronounced. 



The newly developed beetles begin issuing from the ground in 

 August; the first specimens were obtained in this investigation 

 on August 7. In one rearing cage 75 beetles came from the ground 

 between August 13 and September 2, the maximum emergence tak- 

 ing place from August 24 to 29. 



In late summer and early autumn the young beetles may be found 

 on their host trees, where they apparently feed on the leaf petioles 

 before seeking their hibernation quarters. The beetles live through 

 the winter, probably hidden in the duff at the surface of the ground, 



