August, ’18] 
MOORE: CHLORPICRIN FUMIGATION 
359 
Exp. 10. Flour infested with larvse and adults of the confused flour beetle con¬ 
tained in a flat glass dish one and one-half inches deep, and beans infested with the 
bean weevil, contained in a battery jar, were fumigated in the fumigation box of six 
cubic feet capacity for forty-eight hours with carbon bisulphide at the rate of three 
pounds to 1,000 cubic feet. Examination after airing showed all the larvse and adult 
of the confused flour beetle to be dead, while 100 beans contained one living larva 
B,nd one adult out of thirty. The temperature during the experiment was 60°-68° F. 
From these results it is apparent that one-half pound of chlorpicrin 
per 1,000 cubic feet will prove destructive to the bean weevil ( Bruchus 
obtectus Say), the Angumois grain moth ( Sitotroga cerealella Oliv.), the 
Indian meal moth ( Plodia interpunctella Hbn.), Mediterranean flour 
moth ( Ephestia kuehniella Zell.), but is not sufficient to kill the con¬ 
fused flour beetle ( Tribolium confusum Duval) deeper than an inch in 
the flour. For this insect it is necessary to use as much as one or two 
pounds per 1,000 cubic feet. Where the quantity of flour or grain 
fills the entire space of the fumigation box stronger doses would be 
necessary. Carbon bisulphide must be used in our fumigation boxes 
at the rate of from three to eight pounds to produce similar results 
and the temperature must be above 65° F. In using chlorpicrin the 
temperature may be below 60° F. and still give good results as in 
Experiment 8. 
Effect of Chlorpicrin on the Germination of the Grain 
Table I summarizes the results of the effect of chlorpicrin on the 
germination of the grain. 1 
Table I 
24 hrs. 
24 hrs. 
24 hrs, 
24 hrs. 
48 hrs 
Seed 
Check 
2 lbs. 
lh lbs. 
1 lb. 
4 lb. 
\ lb. 
Each per 1,000 cubic feet 
Rye. 
. 82 
67 
Oats. 
. 82 
59 
Wheat. 
. 94 
90 
Barley. 
. 99 
98 
Corn. 
. 93 
95 
Oats. 
........ 99 
97 
Oats. 
. 99 
97 
Oats. 
. 99 
93 
Rye... 
... 79 
30 
71 
Corn. 
. 90 
95 
98 
Corn. 
. 90 
96 
95 
Corn. 
. 93 
92 
Wheat 2 . 
. 88 
60 
66 
72 
81 
64 
Oats. 
. 94 
93 
95 
96 
98 
92 
Rye. 
. 99 
89 
95 
96 
99 
87 
Corn. 
. 90 
96 
95 
95 
98 
Corn. 
. 93 
92 
1 1 wish to thank Mr. Robert Dahlberg of the Division of Plant Pathology and 
Botany who kindly conducted the germination tests of the grain. 
2 This wheat was a poor grade having been injured by mice. 
