ffyttt of 



All these little animals remain in the tree until 

 late spring or early summer, when they emerge 

 in multiplied swarms and repeat the deadly 

 work in other trees. 



The depredations of these insects are enor- 

 mous. During the early eighties the Southern 

 pine beetle ruined several thousand acres of 

 pines in Texas. Ten years later, 1890-92, it 

 swarmed through western North Carolina, Vir- 

 ginia, and West Virginia to southern Pennsyl- 

 vania and over an area aggregating seventy-five 

 thousand square miles, and killed pines of all 

 species and ages, leaving but few alive. Within 

 the past few years the mountain and Western 

 pine beetles have ruined a one-hundred-thou- 

 sand-acre lodge-pole pine tract in northeastern 

 Oregon, destroying not less than ninety per cent 

 of the stand. During the past decade the Black 

 Hills beetle has been active over the Rocky 

 Mountains, where in some districts it has de- 

 stroyed from ten to eighty per cent of the West- 

 ern yellow pines. In the Black Hills the forests 

 over several thousand square miles are ruined. 



These bug-killed trees deteriorate rapidly. In 

 178 



