THK WKSTKKN riNK-I)KSTK< »Y IN<i HA KK KKKTI.E. 2t 



is made lart^cr to accoiiuiKxIatc th('siz(>()f the body. I lavinj; rcacluMl 

 tho outiT hark, it hollows out an oval s|)aco or pupa case, in which to 

 ^o through its transformations. 



NATIK.M. KNEMIES. 



Larva' of the prcdacoous hootlcs of the <ronus (Moms, wliich are 

 knoAvn to j)r(*y u|)on DcMuh'ot'tonus larva-, were (|uito common in and 

 iiTuh'r the hark of the infested trees, and they (h)uhtle.ss hclj) to some 

 extent in keepinii: (h»\vn tlie numbers of the barkbeetles. 



Birds contribute th(>ir ])art also in destroyin<i; larva' and pupa'. The 

 ^vork of Avoodpeckeis was found upon most of the trees which had 

 been killed by D. hrevicomis, and these birds had evidently destroyed 

 a large percentage ol the in.sects in some of the trees. 



METHODS OF COMBATING THE INSECT. 



ri US'l' UIX'OMMENDATIONS. 



The following information and recommendations relating to this 

 insect and methods of ])re venting losses from its ravages were conveyed 

 by Doctor IIoj)kins to Mr. K. M. Hoover, or Boise, Idaho, manager of 

 the Payette LundxT and Manufacturing C\)m])any, in a letter dated 

 January 23, IDOG, and afterw ards published, with Mr. Hoover's reply, in 

 a local newspaper. 



Our sjH'cial iicld afjcnt, Mr. J. L Webl), has submitted lii.s report on forest insect investi- 

 gations in tlie vicinity of Centerville and Smiths Ferry, Idaho, during the past sununer, and 

 it will interest you no douht to know that the insect which is primarily to lilaiiic for the death 

 of pine trees was located and thoroughly studied hy him. 



He found that the hroods of the destructive species pass the winter in the gruh state in the 

 bark of trees which died during the late sununer and fall and that tlicy tio not transform to 

 the V inged form and emerge untilafter the Istof May. Therefore the method of combating 

 the pest is simply to cut the infested trees an}' time between the 1st ol October and the Isi ,,f 

 May and to remove the bark from the main trunk and iuirn it. 



It is nece.s.sary to l>urn the bark in order to kill the broods of this insect, because they 

 occupy the intermediate portion between the iimer surfa<e and the <iuler .scale portion; 

 hence the <irying of the removed bark will not kill them as it would if they occupied the 

 inner moist portion. 



The infested trees can be located ( 1 ) by the yellowish and light re<ldish brown color of the 

 foliage; (2) by cutting mto th<> bark as high upon the trunk as a man can reach with an a.\ 

 to determine whether the middle portion of the bark is mfesteti with the small white grubs, 

 which are about three-sixteenths of an mch long. If the.s<> are found, it will Im* conclusive 

 evidence that the tree has been killed by tlie lu'etle and is mfe.sted with its broods. It must 

 be remembered that tln-re are liundre<ls of otlx-r kinds of in.sects which occupy the iiiiitr |>or- 

 tion of the bark and wooti of such trees, but none of the smaller «tnes pa.ss the winter in the 

 outer bark. • » • 



Perhaps the most important thing for you to do as a preliminary to any delinite action you 

 may take in the matter is to have a number of intelligent cruisers make a survey of vour 

 holdings for the purpose of locating the principal s<'ctions in which trees have died during the 



