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



Plate XVIII. 







I 

 I 



I 



w 



Work of Secondary and Other Enemies of Spruce. 



a, Work of the white spruce bark-beetle ( Tomicus) in white spruce bark; b, work of spruce 

 wood-engraver {Pityophthbrus cariniceps Lee.) in spruce bark and grooving the outer 

 wood; c, galleries of the destructive pine bark-beetle {JDendroctonus frontalis) in pine 

 bark; also attacks spruce; d, work of the small red spruce bark-beetle | Dryoccetes n. sp.) 

 on the surface of spruce wood; e, galleries of the spruce bark-beetle (Polygraphus rufi- 

 pennis Kirby) on surface of pieces of spruce driftwood, found in Parmacheene Lake. 

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



