Bui. 48, Div. of Entomology, U. S. Dept. of Agriculture. 



Plate VI. 



Work of Destructive Pine Bark-beetle. 



a, a. n. a. Chnrnrtcrisiic forinsiif iiriiiiarv KiiHories: h, iinrTiiiil furin.M of Inrv-iil mines: r, abnormal 

 forms of liin-nl mines— all >*liglitly ndurt-il. (Author's illusiratlon, YoarUnik. U.S. I)ct>t. of 

 Agrifiilture. 1902.) 



