XII THE SCOLYTID BEETLES. 
Detailed information on the species — Continued. 
No. 22. The black turpentine' beetle — Continued. Page. 
Economic features 150 
Evidences of attack 150 
Favorable and unfavorable conditions for the beetle 151 
Methods of control 151 
Basis of information 153 
Bibliography " 153 
No. 23. The red turpentine beetle (Dendroctonus vaUns Lee.) 153 
Seasonal history 155 
Overwintering stages 155 
Activity of overwintered broods 155 
Generation 156 
Habits 156 
Economic features 160 
Evidences of attack 161 
Effects on commercial value of the wood 161 
Favorable and unfavorable conditions for the beetle 161 
Methods of control 162 
Basis of information 163 
Bibliography 165 
General bibliography (economic literature) 166 
