98 
THE SCOLYTID BEETLES. 
METHODS OF COXTEOL. 
Whenever it is positively determined that this species is attacking 
living pine timber in a given locality and that the bark of living and 
dying trees contains living parent adults or developing broods, active 
and radical measures should be promptly adopted for its control. 
The simple removal of the infested bark from the main trunks of the 
trees, without burning it, is sufficient to kill the broods of this species, 
provided the work be done between the first of October and the first 
of June. If, in the case of a mod- 
erate outbreak, the larger clumps or 
patches of infested trees and the more 
accessible scattering ones in the worst 
affected sections of a forest are thus 
treated, it should serve to bring the 
pest under control the first year, but 
in the case of a very extensive out- 
break this may require two or three 
years or more. 
If all of the infested trees can be 
barked or utilized and the slabs 
burned without much additional ex- 
pense, it may be best to do so, but 
where, for any reason, this can not 
be done within the specified time, the 
work should be planned so as to in- 
sure the barking or utilization of all 
of those in the larger patches, or an 
aggregate of 75 per cent of the in- 
fested trees to each square mile. 
If the bark be removed from 
the standing trees (figs. 57, 58), an 
aggregate of 75 per cent or more of 
the actually infested bark should 
be removed from all of the trees, 
or all of the infested bark should be 
removed from 75 per cent of the 
trees. The work should be planned 
and conducted with the object of destroying the greatest possible number 
of insects for the labor and time expended. That is, if there are more 
infested trees than can be barked within the specified time, and five 
or six times as many insects can be killed by removing half of the 
infested bark from the standing trees as can be done in the same time 
by felling one tree and removing all of the bark, the former is far pref- 
erable, remembering that it is not necessary to exterminate the enemy, 
Fig. 57.— Removing bark from trunk of 
standing tree with special barking tool 
having handles of different lengths, 
to destroy broods of the Black Hills 
beetle. (Original.) 
