10 BULLETIN 352, U. S. DEPAETMENT OF AGKICULTUEE. 



THE ADULT BEETLE. 



Reaching tlie adult stage in the late summer and early fall, the 

 beetles feed for a few weeks, and then seek out a protected situation 

 in which they pass the winter. According to Pettit (1904) the beetles 

 pass the winter several inches below the surface of the ground. 

 Emerging from hibernation in the spring, they feed again for some 

 time, mate, and the females descend to the base of the trees, where, 

 among the decaying leaves and other vegetable matter, they deposit 

 their eggs. Occasionally they utihze for this purpose accumulations 

 of rubbish in the cavities in the bark of large trees. In such situa- 

 tions eggs have been found as high as 4 feet above the ground. 



INCUBATION PERIOD. 



No definite data on the incubation period were obtained, but on 

 August 3 and 5 two lots of eggs were collected and placed in vials with 

 the rubbish on which th^y were deposited. Most of those of August 3 

 had already hatched, but young larvge continued to emerge until 

 August 14, 11 days after the collection of the eggs. This lot was col- 

 lected on the hills about 4 miles back from the lake. The lot of August 

 5 was collected only about a mile from the lake, and included a much 

 smaller percentage of hatched eggs. This lot continued to produce 

 larvae untn August 18, 13 days after collection. These figures are 

 probably very near to the incubation period for the season of 1915, 

 since Chittenden (1899) records a period of 11 days in 1898 at Wash- 

 ington, D. C. 



THE LARVA. 



In hatching the larva cuts an irregular slit in one side of the egg. 

 It then ascends the tree, and, feeding on the underside of the leaf, 

 grows very rapidly. During its feeding period it molts twice. In 

 molting the skin splits down the middle line of the thorax, the spUt 

 extending on to the head, where it divides and extends to each side 

 of the mouth. The head, thorax, and appendages are withdrawn, 

 and the larva secures a hold on the leaf with its feet and crawls out 

 of its old skin, which remains for some time fastened to the leaf. 



First instar. — In the course of the Hf e-history work 243 larvae were 

 carried through the first instar. Of these 79 required 4 days; 140, 

 5 days; 17, 6 days; 5, 7 days; 1, 10 days; and 1, 11 days. This gives 

 an average period for the first instar of 4.83 days. The first of these 

 hatched on August 5 and the last molted for the first time on August 

 24, tliis being the period in which aU the data on this instar were ob- 

 tained. Table I summarizes these data. 



