I 



258 WEST VIRGINIA EXPERIMENT STATION. 



The presence of this insect may be easily detected by the 

 fine white borings in the loose bark of the standing trees, or 

 beneath the logs on trunks of felled ones. Often the ground 

 under the logs in a skidway will be literally covered with these 

 borings. 



If saw logs are left in the woods or in the skidway for a few 

 weeks between the first of May and the middle of October they 

 are often seriously damaged by this beetle which is exceeding- 

 ly common throughout the spruce forest, in fact, the sapwood 

 is often literally ruined, except for low grade lumber and pulp 

 wood, by the numerous black sapwood pin holes and sap stains 

 resulting from its attack. 



It also attacks the hemlock and pine, especially the white 

 pine, but is more common in the spruce. It is widely distri- 

 buted over North America, and like the European spruce bark 

 beetle, is common in the spruce forests throughout Europe. 



Dr. Packard referred to a bark beetle under the name of this 

 species as the most destructive pest of the spruce, the beetle 

 most concerned in the ravages of spruce forests in Northern New 

 England from 1878 to 1881. 1 But since it is not possible for this 

 wood infesting ambrosia feeder to change its habits to that of a 

 bark beetle, evidently there was some mistake in the identifi- 

 cation of the species, or else the work of a bark beetle was 

 credited to this timber beetle, just as Say credited the work of 

 the bark beetle Tomicus coelatus to the timber beetle Xyle- 

 borus xylographus* owing doubtless, to a wrong reference in 

 the original collecting notes. This is an error which is very 

 easy to make when so many species of bark and timber beetles 

 infest the same tree; or when a timber beetle is found excava- 

 ting an entrance through the bark to the wood. 



ROUND-HEADED WOOD MINERS. 



The character of this class of enemies has been already de- 

 scribed on another page, under the head of "Round-headed Bark 

 Miners." In fact, nearly all of the round-headed, as well as 

 the flat-headed wood miners live for a time in the bark, some 



1 Fifth Report U. S. Ent. Com. 1889-90, p. 823. (The species illustrated, Fig. 276, from 

 drawing by Gissler resembles somewhat Derdnoctonus simplex. A.. D. H.) 



