64 College of Forestry. 
being 49 mm. while the average was 23.1 mm. The number 
of egg niches also varies greatly, the largest number observed 
being sixty, while the average of sixty-six galleries was 18.89. 
The egg niches are typically arranged alternately on op- 
posite sides of the egg gallery and are spaced from 1.5 mm. 
to 2 mm. apart, but this typical arrangement is modified by 
several factors. Where two egg galleries closely parallel each 
other, the egg niches are all or most of them placed on the 
side farthest from the other burrow. Very often the niches 
in the early part of the egg gallery are placed at a consider- 
able distance from each other, while near the end of the gal- 
lery they are made so close together that the eggs cannot be 
placed with their long axes parallel to the gallery as is the 
usual method. 
P. hopkinsi breeds only in thin barked pine and prefers 
recently cut or suddenly killed pine limbs. It is occasionally 
beneficial in attacking and killing limbs weakened by shading 
thus hastening natural pruning. It, however, more often 
renders an injury by attacking either limbs of large trees 
or the trunks of small trees which have been rendered weak 
or sickly from the work of other insects or from other causes. 
Young trees which would otherwise recover are often killed. 
Excessive multiplication of this insect following lumbering 
operations may be prevented by piling the slash and allow- 
ing it to remain as a trap till the beetles have constructed 
their brood burrows. It should then be burned before the 
emergence of the brood. This method will also aid in check- 
ing other more or less injurious forms breeding under simi- 
lar conditions. 
The writer wishes to express his obligations to several 
specialists for their kind and prompt assistance in identify- 
ing the parasitic and predaceous enemies mentioned in the 
body of the paper. Such help is indispensable and is doubly 
gratifying when so freely and promptly given. I am indebted 
to Dr. C. T. Brues and to Dr. A. A. Girault for identifying 
the Hymenopterous parasites, to Prof. H. E. Ewing for 
classifying the two predaceous mites and to Mr. A. B. Wol- 
