X THE SCOLYTID BEETLES. 
Detailed information on the species — Continued. Page. 
No. 10. The Black Hills beetle (Dendroctonus ponderosse Hopk.) 90 
Seasonal history 91 
Overwintering stages ■_ 91 
Activity of overwintered broods 91 
Generation 92 
Habits . . 93 
Economic features 95 
Evidences of attack 95 
Effects on commercial value of the wood 97 
Favorable and unfavorable conditions for the beetle 97 
Methods of control 98 
Basis of information 100 
Bibliography . 101 
No. 11 . The Jeffrey pine beetle (Dendroctonus Jeffrey i Hopk.) 101 
Seasonal history 102 
Overwintering stages 102 
Activity of overwintered broods 102 
Habits 102 
Methods of control 103 
Basis of information 103 
Bibliography 103 
No. 12. The eastern larch beetle (Dendroctonus simplex Lee.) 103 
Seasonal history 104 
Economic features 105 
Methods of control • 105 
Basis of information 105 
Bibliography 106 
No. 13. The Douglas fir beetle (Dendroctonus pseudotsugee Hopk.) 106 
Seasonal history '. 107 
Overwintering stages 107 
Activity of overwintered broods 107 
Generation : 108 
Habits 108 
Economic features 109 
Evidences of attack 109 
Effects on commercial value of the wood Ill 
Favorable and unfavorable conditions for the beetle Ill 
Methods of control Ill 
Basis of information 113 
Bibliography 114 
No. 14. The eastern spruce beetle (Dendroctonus piceaperda Hopk.) 114 
Seasonal history 114 
Overwintering stages 114 
Activity of overwintered broods 115 
Generation 117 
Habits 117 
Economic features 120 
Character of attack and injury 120 
Extent of depredations 122 
Evidences of attack 122 
Effects on commercial value of the wood 123 
Favorable and unfavorable conditions for the beetle 123 
