18 BULLETIN 352, U. S. DEPARTMENT OF AGRICULTURE. 
The proportion of sexes under natural conditions was not deter- 
mined, but among those reared in the life-history cages the males 
and fas sonene in almost exactly equ numbers, there being 
282 males and 281 females. 
SEASONAL-HISTORY SUMMARY. 
The cherry leaf-beetle hibernates in the adult stage. The beetles 
emerge from their winter quarters in the late spring, and, after feed- 
ing for a few weeks and mating, the females go to the bases of the 
trees and deposit their eggs in the accumulation of rubbish. In some- 
thing less than two weeks the eggs hatch. The larve grow rapidly 
and in less than two weeks attain full growth, when they burrow a 
short distance into the ground, pass through their pupal stage, and, 
in from two to three weeks after entering the ground, reappear as 
adult beetles. These beetles feed until cold weather compels them to 
seek shelter for the winter. . 
The season of 1915 was unusually cold and wet, and this condition 
undoubtedly delayed the development of the insect to a considerable 
extent. The hibernating beetles appeared at North East on June 7. 
Within two weeks their numbers were noticeably ‘diminishing, but 
beetles of both sexes were observed as late as August 5, and females 
collected at this time still contained eggs. Unfortunately the natural 
food plant and egg-laying habits were not learned until the 3d of 
August, but at this time many eggs were still unhatched. Larve 
continued to emerge until August 14, and from another lot of eggs 
collected August 5 larve were hatched as late as August 18. At the 
time these eggs were collecte] there were full-grown larve on the 
trees, and many had undoubtedly entered the ground for pupation. 
Larvee were observed on the pin cherry as late as September 10, when 
a full-grown larva and a young third-stage larva were found on some 
foliage that had been brought into the laboratory two days earlier. 
The active feeding portion of the larval life in the cages varied from 
10 to 20 days, the average being 12.33 days. 
The period spent in the ground in the cages varied from 14 to 28 
days, the average being 22.36 days. The total developmental per- 
iod is from 45 to 50 days. 
The earliest adult to emerge in the cages appeared on August 23, 
but the pale, newly emerged beetles were observed in the open on the 
16th. On August 31 the adults of the new brood were abundant on 
pin cherry, while many young beetles and pupez and a few larve were 
found in soil and leaf mold under the bushes. On September 8 adults 
were abundant, but by September 23 they had begun to disappear, 
and no pup could be found in the ground, although a few newly 
- emerged adults were observed. 
