pines show this wor];. In generc.1 , therefore, we must re- 

 member to notice that color is of primary importance, that 

 on closer inspection many show woodpecker work and c.bout 

 one-half pitch tubes. Infest eel trees that have not yet chan . 

 ed, color nay often he spotted *~>y examining the trees near a 

 re centl3 r " killed tree. Trees Gtill green will some tines sh<v; 

 the characteristic woodpecker vork or pitch tubes. 



Sugar Pines:- In .sugar pine, color is the principal rieans 

 of spotting the trees. A very characteristic symptom is the 

 yellowing of the upper half of the crown, followed later "by 

 the lower half. T .7ocdpecker work is often hard to distinguish 

 and the pitch tubes are so near the color of the bark that 

 close inspection is necessary to detect their presence. 



Other Species:- Jeffrey pines can almost always be spotted 

 by the yellowing of the foliage, or when near other infested 

 trees, by reddish pitch tubes. Lodgepole pines show a thin- 

 ning of the needles and a general sickly appearance and. alno;. 

 invariably numerous conspicuous whitish pitch tubes appear on 

 the trunk. Infestations of firs and Douglas firs can only be 

 detected ~by the fact that they are dying. Ho pitch tubes ap- 

 pear, and even entrance holes of the adult beetles are but 

 seldom found. Cedars, except in young growth, die but slowly. 



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