4 INSECTS WHICH KILL FOREST TREES. 



of the particular species of insect responsible for the trouble; and 

 (c) take prompt action toward its control according to specific expert 

 advice, published or otherwise, on the best method for the destruction 

 of the necessary 75 per cent or more of the insects in the infested trees. 

 Some of the methods to be adopted to meet the requirements of 

 various local conditions are as follows: 



(1) Utilize the infested timber and burn the slabs during the 

 period in which the broods of the destructive beetles are in the imma- 

 ture stages or before the developed broods emerge from the bark ; or 



(2) Fell the infested trees and remove the bark from the main 

 trunk and burn the bark if necessary; " or 



(3) Remove the infested bark from the standing timber and burn 

 the bark when necessary ; " or 



(4) Immerse the unbarked logs in ponds, lakes, or streams, where 

 the bark will remain soaked long enough to kill the insects; or 



(5) Remove the unbarked logs or products to a locality where 

 there are no trees liable to attack within a radius of 20 miles or more. 



Maintaining Control of Barkbeetles. 



Future trouble of a serious nature from barkbeetles which kill 

 trees can be prevented within a given forest or area of greater or less 

 extent if an insect-control policy is adopted in connection with, or 

 independent of, a fire-control policy by which groups of dying trees 

 will receive similar prompt attention as that required for the pre- 

 vention or control of forest fires. 



In state and national forests. — In all forest reserves in which there 

 is an organized force of rangers and fire wardens or patrols each 

 officer should be furnished with instructions for the location of 

 beetle-infested trees, and with equipment and directions for taking 

 the necessary action whenever the conditions demand or warrant it. 



In private forests. — Private forests should receive the same atten- 

 tion as public forests, 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 attention. While it may be advisable 

 to have some laws to govern the treatment of timber infested with a 

 dangerous pest when the owner refuses to take any action, such a 

 law should apply only to the more extreme cases or as a last resort 

 on authoritative advice. It is probable that in most cases legislation 

 will not be necessary, and more ultimate good will result without 

 than with strict laws, especially when it can be made clear to the 



"■ If the broods develop to adults in the outer bark, it must be burned ; if they 

 develop in the inner bark and are exposed when the bark is removed, burning 

 is not necessary. As a rule the burning of the tops to destroy the insects is 

 not necessary. 

 [Cir. 125] 



