0 ae 
active are the flies. Many cannot spread their wings and consequently 
are not able to fly, thus inducing death. Others, while seemingly ac-— 
tive, die after two or more days, even though food is administered, and 
it seems only logical that the physiological efficiency of the flies has 
been greatly depleted owing to the strenuous effort exerted while at— 
tempting to come to the surface of the soil. The foregoing considera— 
tions are mainly applicable to flies subjected under 24 and 36 inches 
Or sorta 
Preliminary experiments with HCN treatments for control of adult 
tarnished plant bug.--E. J. Newcomer, Yakima, Wash., reports that "In 
cooperation with S. W. Griffin, of the Bureau of Chemistry and Soils, 
Wenatchee, Wash., some preliminary tests were made to learn whether or 
not fumigation experiments with insects could be carried on successfully 
with the apparatus Mr. Griffin has been using in smelter—fume investiga— 
tions. It was found that this could be done, and several tests of HCN 
were made on adults of the tarnished plant bug. * * * It was evident 
from these tests that at a temperature of about 50°F. a gas concentra-— 
tion of 1,500 parts per million would require 10 minutes to kill all 
the bugs and a gas concentration of about 3,800 parts per million would 
require 5 minutes. This shows rather conclusively that momentary fumi- 
gation, such as might be obtained by dragging a closed container of some 
sort slowly over the ground and keeping it filled with gas, would not he 
successful. It is hoped that further work may be done to find out what 
results might be obtained by using calcium cyanide dust in such a con- 
tainer." 
JAPANESE BEETLE AND ASIATIC BEETLE RESEARCH 
Value of stomach poisons against immature stages of Jap beetle.—— 
"The study of the effect of stomach poisons on the weight of the third—- 
instar larvae of Popillia japonica Newm. was continued," by W. E. Flem— 
ing, F. &. Baker, and L. Koblitsky, Moorestown, N. J., “using pause 
of 100 individuals and weighing each larva daily on an analytical bal- 
ance. Each experiment was continued until approximately half of the lar- 
vae had been killed by the treatment. The study has been completed this 
month (March) with the following stomach poisons: Calcium arsenate, bar-— 
ium arsenate, aluminum arsenate, ferric arsenate, zinc arsenate, and 
lead arsenate. * * * The larvae lost weight when placed in soil con- 
taining any of these arsenicals at the rate of 1,500 pounds per acre. 
* * * when a larva begins to feel the effect of the arsenic it ceases to 
take food into its body and the alimentary tract is gradually cleared of 
food, thus causing a definite loss of weight. The insecticidal results 
in other experiments have shown that barium and calcium arsenates, for 
example, are more toxic than acid lead arsenate. It is interesting to 
note that larvae in soil treated with acid lead arsenate did not lose 
weight as rapidly as those in soil treated with barium arsenate or cal- 
Clum arsenate." 

