48, Div. of Entomology, U. S, Dept of Agricultur 



Plate XX. 



Mines of the Destructive Spruce Wood-borer. 



Surface of the wood of a "peeled" and felled spruce, showing mines, natural 

 size. ( From Bui. 28. n. s., Div. of Entomology. U. S. Dept. of Agriculture.) 



