324 



FOREST IX SECT RAVAGES STOPPED. 



!)}• a prompt canipaii^n against a tlt)urishiiii;- colony of bark 

 beetles on the Ochoco national forest in central Oregon, the gov- 

 ernment is eliminating- a danger which threatened to destroy mil- 

 lions of feet of timber. 



Some authorities claim that the amount of timber killed each 

 vear by insects is equaled only by the annual loss from forest 

 fires. Among the most destructive of these insect enemies are 

 the bark beetles, one of which, the mountain pine beetle, is re- 

 sponsible for most of the damage on the Ochoco forest. This 

 deadly little beetle is less than a quarter of an inch in length, but 

 bears the ponderous scientific name of Doidroctonus iiionticolae 

 Hopk.. which, being interpreted, signifies killer of the mountain 

 pine tree, discovered by Hopkins. 



Its methods of operation are interesting. The mature beetle 

 bores through the bark of the tree and excavates a gallery in the 

 inner living bark and in the outer surface of the wood in which 

 it lays its eggs. When hatched each young larva, or beetle-grub, 

 channels into this growing portion of the trunk, feeding upon the 

 inner bark. When full grown the larva, after passing through a 

 dormant, or pupal, stage becomes a beetle. This beetle then 

 drills out through the bark in July, and, emerging into the world, 

 seeks a fresh tree and starts a new generation. With this "chain- 

 letter" method, it soon infests a large area. The galleries or chan- 

 nels of the larvae girdle the tree and kill it, and the beetle's pres- 

 ence is usually discovered, as it was in the Ochoco forest, by a 

 patch of red-brown dead pine trees in the midst of a mountain- 

 side of green. 



In fighting this forest scourge, the method recommended by 

 the I'ureau of Entomology is followed. The simi)le removal of 

 the bark of infested trees between October and July, while the 

 larvae are still in the tree, is sufficient to kill them. The lumber 

 may then be sold while it is yet sound. On the Ochoco forest. 

 however, there was no market, and the forest officers found that 

 the cheaper and more eflfective method of control was to cut the 

 trees and burn them before ihc new l)r(>i)ds ot beelU'-^ could 

 emerge. In l'^12 the infestation was given a decided check by 

 the cutting of 3300 trees. This summer the attack on the insects 

 was resumed with renewed vigor, and 42 laborers, in charge of a 

 forest officer, cut more than 40.000 trees. As a result of these 

 vigorous measures, the government a])pari.ntly has the beetles 

 under control. 



