STUDIES IN THE LONGEVITY OF INSECTS. 
J. PERcY BAUMBERGER. 
The investigation of the effect of temperature upon insects 
discussed below was undertaken at the suggestion of Professor 
C. W. Woodworth of the Entomological Department of the 
University of California in the fall of 1911. The purpose of the 
original problem was to obtain data on the length of the imago 
stage of the different orders of insects without food and under 
different temperature conditions. 
The present article represents the extension of the original 
simple experiment to a more comprehensive study of the effects 
of temperature. The specific problems studied and the con- 
clusions arrived at are as follows: 
Part 1. Longevity as affected by different constant temperatures: 
(a) -is not correlated with systematic groups, 
(b) differs inversely with these temperatures, 
(c) is approximately proportional with these temperatures, and 
(d) is primarily dependent upon physiological factors. 
Part 2. Longevity as affected by exposure to two different tem- 
peratures: 
(a) is increased when the temperature of first treatment is high or 
low, and 
(b) is decreased when the temperature of first treatment is normal. 
Part 3. Hibernation as affected by exposure to two different tem- 
peratures: 
(a) is not brought to a close when the temperature of first treat- 
ment is normal and the temperature of second treatment is 
high, 
(b) is brought to a close when the temperature of first treatment 
is low; is continued for from ten to twenty-one days and is 
followed by a second treatment at a high temperature, and 
(c) is not brought to a close when the first treatment at a low 
temperature is continued for a period longer than three 
weeks and then followed by a second treatment at a high 
temperature. 
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