BIOLOGY OF THE MEXICAN COTTON BOLL WEEVIL. 19 
reading on the seventh day gave 84° on the soil and 87° above the 
soil in the tumblers. On the twelfth day the temperature was 84° on 
the soil and 86.5° above the soil. Thus, on this particular day, 
weevils developing in 
squares on the plant 
were experiencing 
88° F., or probably 
less, and those in the 
squares which had 
fallen on the ground 
were receiving from 
OD tonellioc he mac- 
cording to whether 
they were shaded or 
exposed to the sun, 
while weevils in the 
insectary were faring 
well at 83.5° to 87° F. 
It has been shown 
that the most  fa- 
vorable temperature 
for development is 
between 838° and 
84° F, 
In order completely 
to check up condi- 
tions maximum and 
minimum thermome- 
ters were installed 
in the field hatch- 
ery. Thus the maxi- fie. 9—Thermometers installed underneath the cotton 
mum and minimum plants in the field to secure soil temperature, Madi- 
son, Fla. 
temperatures experi- 
enced by the weevils after the falling of the infested square (fig. 9) 
were measured. 
EGG-LAYING ACTIVITY OF HIBERNATED FEMALE WEEVILS 
UNDER FIELD CONDITIONS. 
Table IX gives the data on the egg-laying activities of female 
weevils under field conditions on upland cotton squares. The females 
deposited an average of 76 eggs each at a rate of 8.4 eggs per day. 
The maximum number of eggs during any one day was 19. It is 
practically impossible to keep a continuous record of female weevils 
