330 | Annals Entomological Society of America [Vol. VII, 
It has been the general belief among entomologists that many 
insects of the orders Diptera, Lepidoptera and Hymenoptera 
in the imago stage take no food. Recent experiments (Doten 
15) have shown that some parasitic Hymenoptera take food in 
the adult stage. Closer observations may prove this to be the 
case with many of the insects which are at present, thought to 
abstain from food. However, most insects do not feed after 
the eggs are fully developed. Whether or not, starvation is a 
factor in this experiment, must therefore be left undecided for 
the present. 
PAR 
EFFECTS OF EXPOSURE TO TWO DIFFERENT TEMPERATURES ON 
LONGEVITY. 
It was found in Part 1 of these experiments that longevity 
varied greatly according to the physiological conditions of the 
individual—in order to obtain further data on the nature of 
these physiological conditions, the following experiment was 
performed: 
It was thought probable that temperature could produce 
certain of these physiological conditions—therefore, an attempt 
was made to find if exposure to a certain temperature for a short 
time would result in a condition that would be evident in its 
influence on the longevity of the insect at a secondary and 
different temperature. The insects used as objects upon which 
to experiment were the larve of the very common oak tree 
moth (Phryganidia californica). The larvae were placed sep- 
arately in capsules, wired together in sets of tens as explained 
under ‘‘Method”’ in Part 1 of this paper. The sets of capsules 
were then placed in wooden trays at medium or room tempera- 
ture at high or the temperature of a bacteriological incubator 
or at low, the temperature of an ice room, six by twelve by five 
feet. After two days’ preparation at one of these temperatures, 
the larve were transferred to one of the other temperatures 
where they were kept until starvation resulted in death. The 
larvee were examined each day and the date of death recorded. 
‘“Experiment A’’ represents the results on one hundred 
young larve of the first brood of 1913. “Experiment B”’ 
represents the results with eighty-four older larve of the second 
brood of 1912. 
