June, *18] 
QUAYLE: CYANIDE FUMIGATION 
295 
tents. In the high tent the insects were placed in the center, one foot 
from the top, and one foot from the bottom. In the low tent they 
were similarly placed at the top and bottom, but not in the center. 
The gas was generated by the pot method. 
Following is a summary of the experiments: 
Fifty-two Experiments—Bean Weevil ( Acanthoscelides obtectus) 
Dosage, 5-20 oz. 
Exposure, 45-60 min. 
Tent temperature, 13°-24°C. 
High tent SI x 31 
Low tent 22 x 44 
Place in 
tent 
Number 
Insects 
Killed 
(Percent¬ 
age) 
Place in 
tent 
Number 
Insects 
Killed 
(Percent¬ 
age) 
Top. 
. 237 
65.8 
Top. 
.233 
83.7 
Center. 
. 237 
70.8 
Bottom. 
. 231 
35.5 
Bottom.... 
. 225 
55.5 
Totals. 
.'j... 705 
57.5 
Totals. 
.. 458 
69.8 
Twenty-two Experiments—Granary Weevil ( Calandra granaria) 
Dosage, 6-15 
oz. Exposure, 30-60 min. 
Tent temperature, 17°-27°C. 
V 
High tent SI x SI 
Low tent 22 x 44 
Place in 
tent 
Number 
insects 
Killed 
(Percent¬ 
age) 
Place in 
tent 
Number 
insects 
Killed 
(Percent¬ 
age) 
Top. 
. 104 
45.4 
Top. 
. 105 
47.8 
Center. 
. 103 
36.89 
Bottom. 
. 102 
5.88 
Bottom. 
19.04 
Totals. 
. 309 
26.5 
Totals. 
. 205 
33.3 
Twenty-six Experiments- 
-Bean Weevil 
Sulfur, 1-7 oz. and Cyanide, 2-7 oz. Exposure, 50 min. 
High tent 
Low tent 
Place in 
tent 
Number 
insects 
Killed 
(Percent¬ 
age) 
Place in 
tent 
Number 
insects 
Killed 
(Percent¬ 
age) 
Top. 
. 125 
63.2 
Top. 
... 113 
62.0 
Center. 
. 115 
56.0 
Bottom. 
. 113 
34.6 
Bottom. 
44.0 
Totals. 
. 353 
54.1 
Totals. 
57.7 
Twenty-one Experiments- 
—Bean Weevil 
Dosage, 10-18 oz. Exposure, 30-90 min. 
Temperature, 8°-24°C. 
High tent 
Low tent 
Place in 
tent 
Number 
insects 
Killed 
(Percent¬ 
age) 
Place in 
tent 
Number 
insects 
Killed 
(Percent¬ 
age) 
Top. 
. 120 
90.0 
Top. 
90.0 
Center. 
. 120 
85.0 
Bottom. 
. 120 
75.0 
Bottom. 
83.0 
Totals. 
. 360 
83.3 
Totals... 
86.6 
The query stated at the outset seems to be answered by the results 
of the above experiments, also the difference in killing efficiency be¬ 
tween very high and very broad trees. In every case the high and the 
i 
