128 



THE SCOLYTID BEETLES. 



ated slightly in front of the middle, the anterior surface, including the 

 elevation, opaque. The area behind the elevation is impressed and 

 shining; cl3^)eus short, broad, with median groove and its apex sub- 

 acutel}" emarginate (in dried specimens) ; labrum prominent, its ante- 

 rior margin subtruncate; mandibles opaque, with slight dorsal impres- 

 sion or elevation; sternellar lobes of thoracic segments moderately 



Fig. 79. — Dendroctonus piceaperda: Egg gallery and larval mines, a, Egg gallery; 6, boring dust packed 

 in gallery; c, entrance and subsequent or inner gallery; d, larval mines. (Author's illustration.) 



prominent and with distinct foot calli. Larval type labeled "Hopk. 

 U. S. No. 318." 



The most distinctive characters are the opaque mandibles with 

 moderate impression and elevation, and the distinctly elevated ante- 

 rior margin of the epicranium. 



Galleries (fig. 79). — The egg galleries are short, broad, longitudinal, 

 grooving the surface of the wood and deeply grooved in the inner 



