THE GENUS DENDKOCTONUS. 



153 



abrum short, sides nearly parallel, and apex tuberculate. Protho- 

 ■acic tergum with two broad, shining dorsal plates separated by a 

 •ather broad median space, and a smaller lateral plate each side; 

 ;ternellar lobes each with a faint foot callus; the mesoterga and 

 netaterga with shining plates on the lateral lobes. Abdomen with a 

 ■ather prominent tubercle on each epipleurum. Larval type labeled 

 'Hopk. U.S. 2824." 



?IG. Q2.—Dendroctonus valens: Work in bark at base of stump, a, Entrance and pitch tube; &, egg gallery; 

 c, boring dust and resin; d, pupal cell; e, pupa; /, larvae at work feeding on inner living bark; g, exit 

 burrows; h, resulting old scar or basal wound, often referred to as basal fire wound; i, inner bark with 

 outer corky bark removed. (Original.) 



The larva of this species is scarcely to be distinguished from the 

 Dreceding. 



Galleries (figs. 91-93). — The egg galleries are generally longitudinal, 

 nore or less winding, and vary greatly in length, sometimes being 

 k^ery long; they are irregular in width and sometimes with branches, 

 md are shghtly grooved into the surface of the wood. The eggs 

 ire placed in masses at intervals along the sides in the inner bark, 

 md the larvae excavate broad chambers, which vary in size from a 



