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marized by J. C. Evenden and A. L. Gibson, of the Coeur d'Alene, Idaho 
laboratory. Mr. Evenden says: "During this Operation a number of ai f- 
ferent sprays were tested * * * Owing to the habit which the budworm 
larvae have of feeding at the base of the new needles, the insect has 
proved a difficult pest to reach with a spray. Furthermore, it was very 
difficult to secure a good coverage of the new needles, though a number 
of spreaders and stickers were used. * * * Of all of the different stomach 
poisons tested, lead arsenate and fish oil seemed to give the best results 
when applied to the trees when the buds had just opened." 
Parasitism on the Douglas fir beetle.—W. D. Bedard, Coeur d'Alene, 
reporting on the biology of Dendroctonus pseudotsugae Hopk., says: "One of 
the interesting features of this report is the percentage of the Doug-— 
las fir beetle broods parasitized by Coeloides brunneri Vier. * * * an 
average of 29 per cent of the bark—-beetle larvae were destroyed by this 
insect, and an additional 20 per cent destroyed by other less important 
parasites. * * * the parent adult beetles emerge from the first tree at- 
tacked and make another attack upon a different tree, thus increasing the 
potential increase that can be expected from overwintering broods." 
eee ee eee 
tiveness of the burning-standing method of control being practiced against 
Dendroctonus monticolae Hopk., T. T. Terrell, Coeur d'Alene, conducted 
a series of tests "to determine the degree of heat necessary to destroy 
both mountain pine beetle and Douglas fir beetle larvae. As a result of 
these tests it was found that an exposure of 4 to 6 minutes at 114° re- 
sulted in 100 per cent mortality. However, a sustained exposure of 30 
minutes at 110° resulted in only 20 per cent mortality of both these two 
species of larvae." 
Effect of slash on bark-beetle abundance.-J. A. Beal, Portland, 
Oreg., reporting on the effect of ponderosa pine slash on insect abundance, 
says: "The results of the study show that the western pine beetle does 
not ordinarily find suitable breeding conditions in the slash to which 
it is attracted. In only rare cases is it found producing good broods 
under conditions occurring in logging slash. In windthrown trees de- 
velopment of this insect was found to be more successful. The increase 
was about half that obtained from standing infested trees but both at- 
tack and emergence were below normal. The Oregon pine engraver beetle 
was by far the most abundant insect studied, and it increased very rap- 
idly under protected conditions. In shaded material, such as limby tops 
and brush piles, it reproduced itself six times as abundantly as in mater- 
ial exposed to the sun, This insect also emerged in large numbers from 
young standin; trees to which it was attracted. Exposure more than any 
other single factor appeared to influence the number of slash insects. 
High subcortical temperatures of exposed slash were found to be important 
in keeping down the number of slash insects throughout the region studied. 
These temperatures were governed chiefly by sunshine intensity, angle of 
