342 Annals Entomological Society of America _[Vol. VII, 
ty-eight Codling moth larve collected on July 17, at Walnut 
Creek, Cal., thirty-eight pupated, twenty hibernated as larvae 
and twenty-eight died. The temperature at Walnut Creek 
during July in 1909 actually increased three degrees over 
the mean temperature of June. Most larve of the second 
brood leave the fruit by the first of September and ninety-five 
per cent. hibernate as larvaee—yet the temperature in September 
is 3.3° F. higher than the temperature of June. According to 
Simpson (52), at Grand Junction, Colo., of 33 Codling moth 
larve collected July 16-23, 1900, but one hibernated while of 
192 collected from August 30 to September 4, 192 hibernated. 
The mean temperature of June was 63.3°F. of August 67.8°F. 
and of September 61.7°. Yet the percentage of larve that 
hibernated had gradually increased from June to September. 
Sanderson (47) finds that some Lepidoptera of the North 
when introduced into the South, do not have an increased 
number of broods as would be expected nor do southern forms 
have more than the one hibernating period, which is common 
to them in their warmer clime when introduced into the North. 
He bases this statement on the fact that the following insects 
have but one generation in the South: tent caterpillar, peach 
borer, plum curculio, canker-worm, gypsy-moth, brown tail 
moth, and insects effecting native trees, all of which are in- 
digenous to the North. Newell (39) claims that the cotton-boll 
weavil enters hibernation after the first hard freeze and not due 
to a mean average temperature of 60° F. or even of 43° F. 
This is contradicted by Sanderson (46) who claims that weevils 
hibernate when the average temperature falls below 60° F. 
Hunter and Hinds (24) agree with Newell in saying that hiber- 
nation begins after the first hard frost—though if the insect be 
deprived of food, it will go into hibernation when the mean 
average temperature is below 60° F.; at a temperature of 60 
to 65° F. however the adults will starve. 
Moisture may also be a controlling factor of hibernation as 
has been shown in the case of the snail in estivation and hiber- 
nation and also in the case of zestivation in the fish and in the 
Lymnezide. 
Frogs also go into estivation during summer as do plants 
and probably all animal life in arid countries. Loeb (81) points 
out that lack of water may act similarly to a low temperature— 
this may account, he says, for the fact that seeds can be kept 
