(From the Forest" Service, U. 8. Dep.t . of Agriculture.) 



REST INSECT 

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By a prompt campaign against a flourishing colony of "bark beetles 

 the Ochoco national forest in central Oregon, the government is elim- 

 K&ting a danger w^ich threatened to destroy millions of feet of timber. 



Some authorities claim that the amount of timber killed eaoii year 

 "by insects is equalled only by the annual loss from forest fires. Among 

 te most destructive of these insect enemies are the bark beetles, one 



which, the mountain pine beetle, is responsible for most, of the dam- 

 gre on the Ochoco forest. This deadly little beetle is less than a quar- 



of an inch in length, but bears the ponderous scientific name of 

 droctonus monticolae Hopk. which, being interpreted, signifies killer 

 the mountain pine tree, discovered by Hopkins. 



Its methods of operation are interesting. The mature beetle bores 

 ough the bark of the tree and excavates a gallery in the inner living 

 k and in the outer surface of the wood in which it lays its eggs, 

 n hatched each young larva, or beetle-grub, channels into this grow- 

 portitfn of the trunk, feeding upon the inner bark. When full grown 

 the larva, after passing through a dormant, or pupal stage, becomes a 

 etle. This beetle then drills out through the bark in July, and, 



Sing into the world seeks a fresh tree and starts a new generation. 

 h this "chain-letter" method, it soon infests a large area.' The gal- 



or channels of the larvae girdle the tree and kill it, and the 

 etle's presence is usually discovered, as it was in the Ochoco for- 

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

 de of green. 



In fighting this forest scourge, the method recommended by the 

 au of Entomology is followed. The simple removal of the bark of 

 Wfested trees between October and July, while the larvae are still in 

 me tree, is sufficient to kill them. The lumber may then be sold while 



is yet sound. On the Ochoco forest, however, there was no market, and 

 Me forest officers found that the cheaper and more effective method of 



htrol was to cut the trees and burn them before the new broods of 

 etles could emerge. In 1912 the infestation was given a decided check' 



the cutting of 3,500 trees. This summer the attack on the insects 

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

 ficer, cut more than 40,000 trees. As a result of these vigorous meas- 

 the government apparently has the beetles under control. 



