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Cool weather delays emergence of western pine beetle»~—We Je Buck~ 
horn, of the Portland, Oreg,, field laboratory, reports that development of 
Dendroctonus brevicomis Lece, which was very rapid during the month of April, 
has been greatly retarded during May by the generally lower temperatures ine 
cident to cloudy weather, frequent rains, and snows Last year the peak of 
emergence was not reached until the middle of July» This year, owing to an 
early spring, emergence was well under way by April 20 on the south side and 
portions of trees warmed by the direct rays of the sun, but May conditions 
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retarded development and now emergence is only about 85 percent completes 
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On the north side of trees and those portions warmed only by air temperatures, — 
emergence is just starting and, although the bulk of the brood is now in the 
adult stage, about 30 percent is still in the pupal stage. In spite of 
this retardation, emergence this year will be generally much earlier than 
laste 
"Ventilation holes" a misnomer.--Mr. Buckhorn also states that the 
vertical burrows that occur at intervals in the egg tunnels of the western 
pine beetle and extend from the roof of the tunnel to the surface of the 
bark have been called "ventilating burrows", or "ventilation holes", and are 
thought to serve this purpose primarily, in addition to serving as turning 
niches and as holes through which boring dust could be ejected. Recent 
studies show very definitely that these are not ventilation holes, but exit 
holes of the emerging adults. An examination of a large number of western 
pine beetle attacks at various stages of development showed that during the 
construction of egg galleries any hole cut to the bark.surface is not allow- 
ed to remain open but soon is tightly plugged with frass. Not until an 
adult definitely abandons its tunnel and leaves the tree is a ventilation 
hole left open, and not until then are any secondary insects found under the 
barke | However, the adults may leave the tree at any stage of gallery con= 
_ Struction and, as a few apparently become dissatisfied with their work bee 
fore it is well started, openings are left for the entrance of secondaries 
at an early stage of development. Prior to emergence the adults were found 
to feed in the caabium and enlarge the gallery into an irregular chamber free 
from frass. The adult emergence holes are bored directly to the surface 
from these feeding chambers. A tree cage placed over 2 square feet of in- 
fested bark, which developed 72 ventilation holes, caught 66 emerging adults 
this spring. The 6 extra holes were probably caused by some emergence last 
fall. It is also possible that more than one adult may use the same exit 
hole. 
Carpenter ants damage homes in Pacific Northwest.--Fe Pe Keen, of the 
Portland, Oreg.e, field laboratory, states that carpenter ants. (Camponotus 
sppe), largely replacing termites in the Pacific Northwest, appear to be the 
insects of greatest destructiveness to wooden buildings, fence posts, tele~ 
phone poles, and other wooden structures. Numerous cases of excessive damage 
have been called to our attention in the past few months. Yn one case the 
studding and woodwork of a plastered house were riddled with tunnels that ex~ 
tended from the ground to the second storye Extensive repairs had to be 
made, but all of the infested woodwork could not be removed. On our recom 
‘mendation, sodium fluosilicate was injected into the tunnels and proved to 
highly effective in. destroying the colonies and halting damage. 
