THE TROUBLE CAUSED BY INSECTS. 



The evidence obtained from a study of Jill stupes of the afflicted tim- 

 ber, including the living, dying, recently dead, and old dead trees, of 

 all sixes, and under widely varying conditions of altitude, exposure, 

 geological formation, soil, and character of growth, indicates quite 

 clearly that this widespread, unhealthy, dying, and dead condition of 

 the timber is the work of insects. 



THE PRIMARY ENEMY. 



The evidence found also clearly indicates that the insect which makes 

 the first attack on the living trees, and therefore the primary cause of 

 the trouble, is a small, black, bark-boring beetle, belonging to a species 

 heretofore unknown to science, and appears to be peculiar to the Black 

 Hills region. a 



NAME OF THE BEETLE. 



Since this primary enemy has not been distinguished from a number 

 of other bark beetles found in the infested trees, it has not been desig- 



FIG. 1. Work of the pine-destroying beetle of the Black Hill.s, in inner bark of dead tree, a, pri- 

 marygalleries: 6,larvsemines: c, pup?e chambers; <7,exitholes. Reduced about one-half (original). 



nated by a local name. 1 would therefore suggest that hereafter it be 

 designated as "the pine-destroying beetle of the Black Hills," and by 



a Since this was written it has been reported from Colorado. A. D. H. 



