21 
pine-bark beetle* of the middle Appalachian region and the spruce- 
destroying beetle” of the Northeast, will warrant, it is believed, some 
suggestions for the prevention of losses. 
METHODS OF COMBATING THE ENEMY AND PREVENTING LOSSES FROM 
ITS RAVAGES. 
When a trouble has been going on six or seven years and has 
reached the magnitude of the one under consideration, it is very plain 
that unless some natural agencies appear to either modify or check it, 
its control is beyond all human effort. On the other hand, if there 
are beneficial influences at work which are reducing the numbers of 
the insect and checking its destructive ravages, there is much that can 
be done toward aiding nature in the suppression and subjugation of 
an unruly species. The evidences found indicate that the latter is true 
in regard to this trouble. While many freshly attacked living trees 
and thickly infested dying ones were observed in different sections of 
the reserve, showing that great numbers of the beetles are at work 
and continuing the trouble, it was plain that the force of the attack 
has from some cause been materially weakened. 
TO REDUCE THE NUMBERS. 
t appears that the pine-destroying beetle of the Black Hills, like 
its Eastern relatives, depends on the trees killed by it for the aug- 
mentation of its numbers and the perpetuation of its power of killing 
more trees. Therefore it is only necessary that the attacking force be 
further reduced to a point where it can no longer overcome the vital 
resistance of the trees on which it concentrates its attack, in order to 
successfully defeat it and secure its extermination. 
The fact that the attacking force of the enemy is already weakened 
from natural agencies suggests that they can be reduced by artificial 
means below their power of killing more trees next season, and thus 
bring the trouble to an end. Therefore the following are suggested 
and recommended as probably the best methods of accomplishing this 
result: 
(1) Determine the location and extent of areas in which trees were 
attacked during the summer and fall of 1901 and the number of trees 
now infested with living broods of the pine-destroying beetle. 
(2) Select those areas in which there are the largest number of 
infested trees and mark the same for cutting. 
(8) Secure, by sale contracts or otherwise, the cutting of these trees 
and the removal of the bark from the infested parts of the main trunks 
and stumps prior to the Ist of May, 1902. The drying of the removed 
® Dendroctonus frontalis (Zimm.) var. destructor Hopk., Bul. 56, W. Va. Agric. Exp. 
Station, 1899. 
» Dendroctonus piceaperda Hopk., Bul. 28 n. s., Div. Ent., U. S. Dept. Agric., 1901. 
