UNITED STATES DEPARTMENT OF AGRICULTURE 

 FOREST SERVICE 



(Prom the Forest Service, United States department of Agr icu Iturc 



3 cm IT an Cisco Office) 



FOREST INSECTS 



Turin-; November and throughout the winter, the 

 government rengers in California will carry on the- ir regular 

 campaign a gainst che pine beetle. There are nearly one hundred 

 centers of insect infestation on ohe National Forests, on] T ~ a fev 

 of which can be attended xo this winter on account of lack of 

 funds. Forest officers expect, however, to clean up an area of 

 about 20C, OCu acres before s-rring. 



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The beetles work entirely in green trees or in trec; r 

 that have been freshly feller. "hey- do not breed in dry logs, 

 but are particularly fond of trees whose giowr.h has been checked. 

 by ground fires or otherwise. The-- bore into the tree as far as 

 ohe soft tissue thai, lies between 'che bark and the wood, where 

 they excav: ce galleries and lay bheir egys. v 'Len 'c].e galleries 

 in a tree are 'so numerous there they connect, the tree is girdled 

 and dies, the needles taking o: a characteristic yellow-brown 

 color. By the ti.-.e a tree has Become a "sorrel top" bhe insects 

 Slave matured and lef , it. 



The treatment consists in locating the trees con- 

 fining eggs or larvae, felling chem, peeling the bark and burn- 

 ing it. 



4 1 !! not destroyed bv ground fires 



Io is thought by rnrny persons that the tree-des'cro T *- 

 ing -insects are encouraged by the suppression of forest fires, 

 ?he clai:;. is made that che lack of fire causes debris to collect 

 which provides a breeding-place for insects. Forest officers vho 



ave given the subject scientific study say that this claim is 

 mtirely unfounded, since at no period of its life history can 

 :he beetle be found in dry material. On the contrary, lisht fires 



"hich do not kill the trees but only scorch them slightly may 

 create the most favorable conditions for insect infestation. 



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