History and Habits of Pityogenes. 47 
These observations were made upon broods started in the 
laboratory under somewhat unnatural conditions but an at- 
tempt was made to keep the conditions as nearly normal as 
possible. How successful this attempt was may be shown 
from the following observations in the field. On May 8th 
numerous brood burrows were observed in which the first 
few eggs had already been laid but these were still pearly 
white and from the length of the egg burrows had been laid 
within a day at most. On June 6th many full grown larvae 
and pupae were present and on July 8th “ ventilation open- 
ings were numerous and a number of the new generation had 
already emerged. When these specimens were confined in a 
breeding jar with fresh pine limbs, they immediately started 
new brood burrows. If the eggs were one day old at the time 
they were first observed and the burrow had been started six 
days before (which in warm weather would be ample time) 
the entire life history would oceupy just 68 days, or within 
two days of the time required in the laboratory. It would 
then seem safe to conclude that the life history of the spring 
brood from the starting of the parent brood burrow to the 
starting of that of the new generation, occupies from 60 to 
75 days depending upon conditions of temperature and 
moisture. 
Seasonat Hisrory.— The number of generations of P. 
hopkinsi occurring each year varies with the weather condi- 
tions. Careful study carried over three seasons leaves no 
doubt that in the vicinity of Syracuse, N. Y., from one and a 
half to two and.a half generations are completed each year. 
Beetles reaching the adult condition in the late fall, just at 
the advent of cold weather, remain in their larval host 
throughout the winter. With the first warm days of spring 
they begin feeding anew and after several days of favorable 
weather, emerge and seek a new host for the construction 
of their brood burrows. This usually occurs in the latter 
part of April or early in May, but varies within a period of 
several weeks dependent upon the weather. 
Most of the new generation to which these give rise, 
emerge during the first half of July and immediately attack 
