
-~ 13 - 
of the western pine beetle ranging from 6 per cent to 92 per cent in the 
Ochoco and Deschutes National Forests in eastern Oregon, following low 
winter temperatures, They state that of the factors affecting mortality 
bark thickness has the greatest effect. Bark 1 inch or less in thickness 
usually showed a brood mortality of 80 per cent or more. Bark from 11/2 
to 2 inches thick showed mortality ranging from 6 per cent to over 60 
per cent. The average mortality of the western pine beetle in all the bark 
Sampled was about 50 per cent. However, "the bark examinations showed 
that there had been some brood mortality before the freeze. * * * Many 
dead temnochilids were also found in the bark, although small dipterous 
parasites were often found living in bark where pine beetle brood had 
died of cold. Mr. Buckhorn also found many dead cerambycids and some 
dead brood of the red turpentine beetle (Dendroctonus valens Lec.) in 
‘the field." Recommendations for curtailment of control work in. this 
area will await further examination of samples, but it is believed 
that this unexpected aid from Jack Frost will serve to reduce the burden 
_of control cost. 
Airplane collections of insects in New England,—-In October, 1932, 
W. L. Baker submitted for determination insect material collected in 
an airplane insect trap in May, 1932. These species have been identi- 
fied by Bureau specialists. Two male gipsy moths were taken at an al- 
titude of 1,000 feet and 1 between 300 and 500 feet. Other insects ta- 
ken at the highest altitudes were: 1 Aphidius nigripes Ashm. at 700 to 
1,500 feet; 1 Hoplogryon at 1,000 feet; and 2 Harmolita at 1,000 feet 
and 1 at 2,000 feet. 
Control of Douglas fir beetle in Cody Canyon.--E, E. Miller, Coeur 
d'Alene, Idaho, reports the completion of the second season's work in 
bark-beetle control in Cody Canyon. This project was instituted in 
the fall of 1931 and was directed against. an epidemic of the Douglas 
fir beetle in a stand of Douglas fir already weakened by spruce budworm 
defoliation. In 1931, 12,038 infested trees were treated and a reduc-— 
t20n,.0f 55 per cent of the infested trees was reported. The work in 
1932 brings out the fact that the reduction in beetle population from 
the work in 1931 was actually much greater than 55 per cent, as the trees 
treated were very heavily infested, the attacks reaching well up into 
the boles. In 1932, new areas containing 2,500 trees were added to the 
project, bringing the number of trees treated in the past season to 
8,158. The trees were treated at a total labor cost of $0.763 per tree. 
The results of the 1932 operation will be mepanied after a survey to 
be made in August, Leis 
CEREAL AND FORAGE INSECTS 
Lethal effect of low temperature on pea aphid.--L. P. Rockwood, 
Forest Grove, Oreg., reports as follows on observations on Illinoia pisi 
Kalt. on vetch and Austrian winter field peas: "The fall was wet and mild 
until December 7. On that date, the wind shifted to the east and it be- 
