358 
JOURNAL OF ECONOMIC ENTOMOLOGY 
[Vol. II 
Effect of Fumigation on Insects Infesting Grain 
Exp. 1. Ears of corn infested with adult saw-toothed grain beetle ( Silvanus surin- 
amensis Linn.) and pupae of the Indian meal moth ( Plodia interpunctella Hbn.) 
fumigated wdth chlorpicrin at the rate of one-half pound per 1,000 cubic feet under a 
bell jar for twenty-four hours at a temperature of 70°-80° F. Insects killed. 
Exp. 2. Flour infested with adult confused flour beetle ( Tribolium confusum 
Duval) was placed in a battery jar to a depth of three inches. Fumigated under bell' 
jar at rate of one-half pound of chlorpicrin to 1,000 cubic feet for twenty-four hours, 
at a temperature of 72° F. Beetles all killed. 
Exp. 3. Flour infested with larvae and adults of confused flour beetle fumigated 
as in preceding experiment, but using one pound of chlorpicrin per 1,000 cubic feet 
for twenty-four hours, temperature 72° F. Adult beetles were killed, but all the 
larvae were still alive. 
Exp. 4. Corn meal infested with larvae of Mediterranean flour moth ( Ephestia 
kuehniella Zell.) placed in paper flour bag. Flour infested with adult confused flour 
beetle contained in a battery jar to the depth of five inches. Corn on the ear infested 
with saw-toothed grain beetle. All fumigated in a wooden box of six cubic feet 
capacity for twenty-four hours at a temperature of 70° F. using chlorpicrin at the 
rate of one-half pound per 1,000 cubic feet. Mediterranean flour moth and the adult 
saw-toothed grain beetles all dead. Confused flour beetles, buried in the flour, sur¬ 
vived the fumigation. 
Exp. 5. Beans infested with larvae, pupae and adults of the bean weevil ( Bruchus 
obtectus Say); whole wheat flour with cocoons of Mediterranean flour moth and white 
flour with all stages of the confused flour beetle. Each was contained in paper bags 
which were placed in the wooden fumigation box and fumigated with one pound of 
chlorpicrin per 1,000 cubic feet of space for twenty-four hours at a temperature of 
70° F. All the insects were killed. 
Exp. 6. Beans infested with larvae, pupae and adults of the bean weevil w r ere 
fumigated as in the preceding experiment, but using one-half pound of chlorpicrin 
for each 1,000 cubic feet. All insects destroyed. 
Exp. 7. Twenty-five and fifty pound sacks of flour infested with all stages of the 
confused flour beetle were placed in different parts, some near the top, others at the- 
bottom of a wooden fumigation box of 180 cubic feet capacity. These were fumigated 
with chlorpicrin at the rate of one pound per 1,000 cubic feet for twenty-four hours 
at a temperature of 70°-75° F. Flour was thoroughly aired and then sifted and the 
insects examined. They were then placed in the open and reexamined twenty-four 
hours later. Both examinations failed to reveal a single live insect. Some of the 
flour was kept for three months, but no insects developed in it. 
Exp. 8. Ears of corn infested with larvae, pupae and adults of the Angumois grain 
moth ( Sitotroga cerealella Oliv.) were fumigated in the wooden box of six cubic feet 
capacity with chlorpicrin at the rate of one-half pound per 1,000 cubic feet at a. 
temperature of 55° to 61° F. for twenty-four hours. After thorough airing, examina¬ 
tion of the ears showed only dead larvae, pupae and adults. The ears were kept for 
two months and since no further evidence of the moth could be detected 100 per cent 
must have been killed. 
Exp. 9. Beans infested with the bean weevil larvae, pupae and adults, and flour 
infested with confused flour beetle were fumigated in fumigation box of six cubic 
feet capacity for twenty-one hours at the rate of one-half pound per 1,000 cubic feet. 
Temperature during fumigation 65°-70° F. All stages of the bean weevil were killed, 
but the flour beetles deeper than from one and one-half to two inches in the flour 
survived. 
