am (8) LO rae 
ducted to determine if there was a sex difference in the resistance of 
the house fly (Musca domestica L.), to kerosene extract of pyrethrum. Ten 
lots of flies of various sex ratios were each sprayed with 0.7 cc of a 
kerosene-pyrethrum extract. Four hours after spraying, the dead flies 
were removed, counted, and the sex was determined for a sample of 500. 
The live flies were killed, counted, and the sex was determined for a 
sample of 500. It was noted that the females were markedly more resist— 
ant to kerosene-—pyrethrum extract than were the males." 
STORED PRODUCT INSECTS 
Time of planting peas as affecting weevil infestation.—-T. A. 
Brindley, Moscow, Idaho, reports that "peas planted on June 22, the 12th 
weekly planting in the series to determine the influence of the time of 
planting on the extent of weevil infestation, have remained practically 
Pree trom weevil injury.” 
Flour mills fumigated by piped system show good kill.—-Geo. B. Wag- 
ner, Kansas, City, Mo., reports the fumigation of two mills, using liquid 
hycrocyanic acid through the new piping system. In the first experiment 
"The mill closed down at 5 p. m. Elevator boots were cleaned, and the 
ends of the conveyers, where large quantities of accumulated stocks were 
located, were also cleaned. Ventilators were sealed and the mill closed. 
The gas was placed in the mill at 6:30 p. m. and at 5:40 a.m, the mill 
was opened." The exposure for 11 hours at optimum temperature and hu-— 
midity, using a dosage of 5 ounces, resulted in a kill of 99.4 percent. 
In the other mill the temperature was 85° to 86° F., the humidity 41 to 
Sl percent, the wind velocity from 4 to 20 miles per hour. The dosage 
used was approximately 6 ounces of liquid HCN; the period of exposure, 
12 hours; and the resultant kill, 95 percent. Mr. Wagner says, "When 
using the machinery piping method of fumigation it is important to make . 
sure the feeder gates above the rolls are open and that no accumulations 
are above these feeder gates. It is also very important that the ven— 
tilators on the air suction lines are well sealed, for these are directly 
connected to every machine in the mill, and if they are not sealed a 
perfect outlet is provided for the gas." 
