282 WEST VIRGINIA EXPERIMENT STATION. 



sensative nature of the more valuable kinds ; as the yellow and 

 white, they suffer more severely on this account than does any 

 of the other kinds of timber trees. Man has, of course, been its 

 greatest enemy in its direct destruction, and in bringing about 

 changed conditions which were unfavorable lor its healthy 

 growth , also as the originator of forest fires, which is perhaps 

 its greatest enemy, insects come next and ranking nearly as 

 high as fire. As a destructive enemy of large trees it has in 

 this State caused a far greater loss of such timber than has fire. 

 Fire is however, more destructive to the young growth. Heavy 

 wind, snow-storms, etc., are other serious enemies or destruc- 

 tive elements to the pine, while numerous small and larsje 

 animals may be classed among its natural enemies. 



The destruction of valuable pine timber, within recent years 

 over vast, aggregate areas in this and adjoining States, by one 

 species of insect aided by its numerous insect and other allies 

 has rendered the investigation of the trouble and a study of 

 the past and present conditions and distribution of the pine in 

 West Virginia the most extensive and important work under- 

 taken by this department of the Station. 



With what additions I have been able to make from personal 

 observations it is found that over 400 different kinds of insects 

 infest the pines of North America, the greater number of which 

 occur in the eastern United States. I have fonnd, however, 

 out of this vast number, that those kinds which are capable of 

 attacking healthy trees, and killing them on their own account, 

 do not exceed possibly a half a dozen species, and probably but 

 one that is capable of causing widespread devastation of pine 

 timber. This is the destructive pine bark beetle, (Dendroc- 

 tonus frontalis,) which will be fully discussed further on in 

 this report. 



HISTORY OF THE INVESTIGATION. 



TO DETERMINE THE CAUSE OF THE UNHEALTHY CONDITION OF THE 



TIMBER. 



First Information, My attention was first called to an un- 

 healthy condition of the pine by Capt. Parsons, of Davis; W. 



