18 BULLETIN 926, U. S. DEPARTMENT OF AGRICULTURE. 
When the thermometer was wrapped in cool, green leaves it regis- 
tered 89° F., but when inserted into a square and wrapped in green 
leaves it registered 81°. 
The thermometer covered one-fourth inch by hot sand in the sun 
registered 106.5° to 107.5° F.; under one-half inch of sand it regis- 
tered 99°, under 1 inch 95° , and under 1 inches of sand 91°. 
Thus i burial of infested squares would merely give the 
immature weevils more favorable temperatures and almost insure 
emergence: while the sun-heated surface soil, even on this moderate 
day. was heated very close to a fatal temperature. 
e secured to check 
Dr. Pierce then studied the temperature in the field breeding cages 
and found in the oviposition cage an air temperature of 85° F., a soil 
temperature in the sun of 108° to 108.5°, in the ute of the wire 
screen 90° to 94.5°, and in the shade of the plant 92° to 95°. The 
humidity in the cage was 71.5 per cent, wet bulb 85. while in the 
open air it was 68.5 per cent, wet bulb 85.5. There is therefore very 
little difference in the temperature in and out of the cage. 
The small wire-screen cages used to cover the squares during the 
last two days before emergence were then measured. In the shade of 
the plant the temperature was 94.5° to 96.5° F. and in the sun 103° to 
106°. The cage, therefore, serves to mitigate slightly the intense heat. 
In the insectary measurements were made in the breeding tumblers. 
A temperature of §3.5° F. was recorded for the soil in the tumblers, 
while above the soil the temperature was 86.5° F. Since the tumblers 
were only moistened once during the hatching period, a temperature 
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