44 INSECTS AFFECTING STORED PRODUCTS. 
While a few dead insects could be found, in the main they ap- 
peared to be unharmed by the fumigation 24 hours later. 
The nonsuccess of this experiment is attributed to the temperature, 
which kept the insects torpid while exposed to the gas, and bears out 
the writer’s experience, which he has frequently expressed in corre- 
spondence for several years. 
Experiment No. 22.—Conditions the same as for Experiments Nos. 
5 and 6, but strength 2 pounds of bisulphid of carbon to 1,000 cubic 
feet of air space. Starting temperature, 70° F.; at end of 48 hours, 
58° I. During this time the temperature ranged as high as 72° and 
as low as 50°. The average could not be determined, but at the begin- 
ning of the experiment it was probably high long enough for the 
gas to take effect, while the low temperature occurred probably at 
a time when it was somewhat immaterial. When the fumigating 
box was opened at the end of 48 hours the odor of bisulphid was 
sufficiently strong to attract the attention of several persons in the 
neighborhood. In this case the beetles of this species, which were 
living in ground rice for poultry feed, were all destroyed. A num- 
ber of other insects, six species in all, was confined under the same 
conditions, and all were killed. 
Experiment No. 23.—Conditions the same as in Experiment No. 8, 
a duplicate fumigating box being used and 2} pounds of bisulphid 
of carbon liberated, with same temperature, and exposure the same, 
namely, 48 hours. Every insect was killed. 
Conclusions—These experiments show conclusively that in in- 
closures made approximately air-tight, 2 pounds of bisulphid of 
carbon, with a full exposure of 48 hours in a temperature approxi- 
mating 65° to 70° F., will prove fatal to the lesser grain-borer, as 
well as to practically any other stored-product insects. 
