
MONTHLY LETTER OF THE BUREAU OF ENTOMOLOC 
¥ UNITED STATES DEPARTMENT OF AGRICULTURS.~ 
Number 76 August, 1920. 
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FOREST ENTOMOLOGY 
A. D. Hopkins, Entomologist in Charge 

| “J. HE. Patterson, of the Pacific Slope Field Station at Ashland; Orég., 
_ reports that during the month of July he and P. D. Sergent have been conducting 
_ investigations to determine the influence of slash on a normal infestation of 
_ Dendroctonus brevicomis Lec. in western yellow pine. This slash was recently 
removed from a highway which is now in course of construction through the Cas- 
cade Mountains in Southern Oregon, and passes through a heavy stand of high 
: grade western yellow pine. As many mature trees of this species were felled 
and removed from the roadway to the surrounding standing timber the opportuni- 
ties offered for this study are ideal, y me eek 
q Investigations of insect injury to mesquite wood carried on during the 
- past three years in Arizona have resulted in determining means of preventing 
_ this loss for all practical purposes. The experimental work was done at the 
Southern Rocky Mountain Field Station near Tucson, Ariz., by W. D. Edmonston 
and George Hofer under the direction of Dr. F. C. Craighead. The preliminary 
results will shortly be published as a Farmers’ Bulletin. This region is de- 
pendent in a great measure on mesquite wood for fuel and fencing, posts, and 
timbers for frame and roofs of adobe houses. Fuel wood is selling for from $20 
to $24.a cord. As much of the wood is cut in the early spring and fall it is 
Subject to severe damage by numerous species of insects in the order Coleoptera. 
The investigations this season have been confined to life-history studies of 
some of the many insects feeding in mesquite. Many interesting facts on the 
more important of ‘these insects have been determined by Messrs. Edmonston and 
Hofer. : | ) 
The bagworm has been very injurious during the last of July and August 
throughout the southeastern United States, particularly on young arborvitae 
shade trees. 
Karwigs are reported to be seriously damaging shade trees and other 
vegetation in Portland, Oreg. This is a rather unusual type of injury in the 
case of shade trees. 
This branch of the Bureau is’ endeavoring to obtain figures on the number 
of shade trees in the United States and an estimate of their value. We would be 
pleased to have any estimates or figures in regard to this from men in the 
Bureau located in various cities throughout the country. 
BEE CULTURE 
E, F. Phillips, Apiculturist in Charge 
A Chautauqua for Wisconsin beekeepers was held on the oath telnet Becks 3b ft 
gonsin camp grounds during the week of August 16-21. Dr. B. F. Phillips and 
G. $. Demuth conducted the extension short course for commercial beekeepers simi- 
lar to those condu:ted previously in various parts cf the country. Nearly 200 
peekeepers from Wiszonsin and adjacent States registered for this short course. 
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