leries are "brought out. The descriptions are given in the 

 order of the economic importance of the beetles. 



Pines. 



PErrpROCTONTJS B3EVICOMIS, LUC . 



(The Western Pine Beetle.) 

 Host - Yellow pine (Pinus ponderosa. ) 



This "beetle, ab^ut 1/8 to 3/16 inch in length, 

 is not known to attack any other pine. The adxilt beetle boron 

 through the cork bark to the inner bark and projects winding 

 galleries through the inner layers between the oixter bark and 

 sapw^od. The gallery is generally filled with pitchy sawdust 

 and the eggs are laid in this sawdiict along the margins of th r 

 gallery. When the eggs hatch the larvae enter the bark. 

 Slicing the cork bark scales on an infested tree -//ill expose 

 the grub. These grubs have the appearance of having been shot 

 into the tree. Sometimes in slicing this bark only the holes 

 in the cork bark will appear. These holes are perfectly round, 

 resembling small shot holes, and are usually numerous. If . 

 these "&I'/ot holes" appear on the outer surface of the bark, an-" 1 

 are numerous, the brood, or the greater part ?f the brood, has . 

 emerged and attacked some other tree. If they appear as opea 

 holes only after slicing off the outer surface, the full- 

 fledged beetle is generally in the hole awaiting a favorable 



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