32 THE SCOLYTID BEETLES. 
operations can be directed and concentrated upon the principal 
areas so that a large percentage of the timber can be cut, barked, 
or otherwise treated before the broods begin to emerge, the desired 
control may be effected with little additional expense, or even at a 
profit. If this method can not be adopted, the force should be 
directed to removing as large a percentage as possible of the infested 
bark from the standing infested trees or from those felled for that 
purpose. The first work should be done in the principal areas and 
larger patches. The work should be planned and executed with 
the object of destroying the greatest possible number of broods for 
the time and labor involved; 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 three or four trees as could be done in the same time by remov- 
ing all of the infested bark from one tree, the former procedure is 
far preferable. 
HOW TO CONTROL A LIMITED ATTACK. 
Whenever it is determined that one or more species is attacking 
and killing small patches of timber hi a given locality or forest of 
greater or less extent and that the bark of the living and dying trees 
contains living parent adults and developing broods, prompt and. if 
necessary, radical action should be taken before the adults begin to 
emerge and fly. 
HOW TO MAINTAIN COXTEOL. 
IX STATE AXD XATIOXAL FORESTS. 
In State and National forests, and in all other forests in which there 
is an organized force of rangers and fire wardens or patrols, each officer 
should be furnished with the necessary instructions for the location 
of beetle-infested trees and with equipment and directions for taking 
the necessary action whenever the conditions demand it. It has been 
demonstrated that any intelligent ranger or manager can become 
proficient in locating and marking infested trees with comparatively 
little instruction in addition to that already published or conveyed 
in special recommendations. 
It is not necessary that every isolated infested tree should be 
treated, but it is of especial importance that all groups of infested 
trees should receive prompt attention. 
IX PRIVATE FORESTS. 
Private forests should receive the same attention as reserves, but 
this is often far more difficult on account of intervening forests where 
the owners either can not or will not give the matter the required 
