48 



chcckiiiji: and i^ive somo prol action from tlie elements. Sucli loi^s 

 could then be taken out when leached in the regular euttiuii- and log- 

 ging operations. 



III. To gii'dle liealthy trees in June lo attract the beetles away fi-om 

 timbei' thai it is desired to protect, the gii-dled trees to 1k' cut and 

 peeled, or placed in the water, in the ordinaiy i)ractice of logging, 

 previous to the first of the following June. 



The use of girdled trap trees has the advantage of not only facili- 

 tating the destruction of the insects, but of attracting them away from 

 the matured timliiM- that ir is desired to leave standing for future cut- 

 ting. Still anothci- advantage lies in the fact that trees may usually 

 be selected for this purpose which in the regular logging operations 

 could be (uit and hauled to the streams within the limited time 

 required. The beetles which are attracted to the trees in this manner 

 may be disposed of l\v either of the preceding methods mentioned, so 

 that tlu^ only additional exi^ense over tlie regulai- logging operat ions 

 would be the cost of gii'dling. 



The infested s[)i'uce which can not be reached by the extension or 

 adjustment of the summer and wintei' logging operations might be 

 felled andjhe bark removed fi-om the infested portions of the trunks 

 any time between the first of August and the first of the following 

 Ju]u>. The young stages of the insects and most of the adults would 

 thus be destroyed by the diying of the ])ark in summer, or by freezing 

 if I'emoved in the winter. 



Another method would be to fell and "score" (by cutting thi-ougli 

 the bark) the top of the infest e<l poi'tion of the felled ti-unks oi- logs 

 to let in the water, which, it is believed, would thus produce an 

 unnatural condition which would kill most of the insects. Experi- 

 ments are suggested to test the effects of water absorbed by the 

 unpeeled logs whether left in the woods or placed in the water. The 

 adoption of this method is not recommended, how^ever, until expei-i- 

 ments prove its value aiul the conditions are found to be favorable for 

 its })i-actical api)lication. 



When the timber is dying i-apidly in a given area of greater or less 

 extent, and the ti'ouble is i)ercei)t ibly spi'eading, and upon examina- 

 tion it is found that there ar<' compai'atively few insect enemies of the 

 beetle, eithci- oi- all of the tliree methods should, undei- favorable con- 

 ditions for theii- practical adoption, j)rove of great service in prevent- 

 ing the uiidue multiplication of the pest and protecting the living 

 timbei' from attack. 



If the trouble seems to be on the decrease, and upon examination it 

 is found that a lai'ge number of natural (Miemies ai-e operat ing on dif- 

 ferent stages of the spruces Ixietle, it may not b(^ necessaiy to take 

 active measures for reducing their numbei-s. Indeed, under specially 

 favorable conditions for the enemies U) opei-at(\ it may l»c best to do 

 nothing, for under such conditions an attempt to destroy the enemy 



