= A = 
Paradichlorobenzene effective against rice weevil.-—Additional 
data on the effectiveness of paradichlorobenzene as a fumigant for the rice 
weevil (Sitophilus oryzae L.) is submitted by G. W. Ellington of Sligo, 
Md.: A 150—pound sack of wheat heavily infested with weevil adults and 
slightly infested with larvae of the cadelle (Tenebroides mauritanicus L.) 
was fumigated in a tight vault of 500 cubic feet capacity at a constant 
temperature of 80°F. It was left there for 15 days, but records were kept 
for only 5 days. Four pounds of the fumigant per 1,000 cubic feet were 
used, spread over papers distributed within the vault. The dosage used 
is about 7 times that known to. give 100 per cent saturation for the 
Space and temperature mentioned. The percentages of kill obtained fol-— 
low: Sitophilus, after 1 day, 30 per cent; after 2 days, 90 per cent; 
after 3, 4, and 5 days, respectively, 100 per cent; cadelle larvae, after 
1 and 2 days, respectively, none killed; after 3 days, 20 per cent; after 
4 days, 88 per cent; after 5 days, 100 per cent. 


Bean weevil infestation gains.-C. K. Fisher, of the bean weevil 
investigations, Modesto, Calif., reports results of the examination of 
warehouse samples in 1931. It is interesting to compare the number of 
samples showing infestation for the 1931 crop, 72.26 per cent, with those 
for 1930, 1929, and 1928, which were 32.21 per cent, 51.86 per cent, and 
67.45 per cent, respectively. The increase in infestation in 1931 is 
40.05 per cent over that in 1930. 
Pea weevil controlled by burning.-A. 0. Larson, Corvallis, Oreg., 
says: "During the month (February) we have made examinations for pea 
weevils in fence posts and trees adjoining pea fields in five counties 
of western Oregon. * * * Fifteen fields were examined. The straw on the 
stubble of eight of these had been burned shortly after harvest last fall. 
* * * Half of one field had been burned and half had been left unburned. 
Six fields had not been burned. * * * there was a very marked differ— 
ence between the numbers of weevils found near burned fields and the 
number found near unburned fields." Where fields had not been burned 
many weevils were found, whereas fields that had been burned showed few 
weevils or none. Mr. Larson did not have the opportunity to check the 
conditions of hibernation in the burned fields with conditions surround-— 
ing these fields, but states that "in this section burning the pea stub— 
ble immediately after harvest promises to hold down the pea weevil in- 
festation." 
Tom Brindley, Moscow, Idaho, reports as follows: "The mortality 
among pea weevils hibernating in fence posts increased to 54.8 per cent. 
This sample was collected on the day following one during which the 
temperature dropped to--80° F." | 
A 
Calif., reports a device "described to us by two workers who have been in 
contact with attempts made by the California Almond Growers Exchange to 
secure satisfactory kills during cold weather inthe two vacuum fumiga-— 
tors installed on the roof of the Sacramento plant of the Exchange. It is 
