Circular No. 1 27. issued December 7, 1910. 



United States Department of Agriculture, 



BUREAU OF ENTOMOLOGY. 

 L. O. HOWARD, Entomologist and Chief of Bureau. 



INSECT INJURIES TO THE WOOD OF DYING AND DEAD 



TREES." 



By A. D. Hopkins,' 

 In Charge of Forest Insect Investigations. 



Timber dying from insect attack and other causes, including fire, 

 disease, storms, etc., is attacked by certain wood-boring insects which 

 extend their burrows through the sound sapwood and heartwood, and 

 thus contribute to the rapid deterioration and decay of a commodity 

 which otherwise would be available commercially during periods of 

 from one to twenty years or more after the death of the trees, depend- 

 ing on the species of trees and on the character of the product desired. 

 This loss often amounts to from 25 to 100 per cent during the period 

 in which the dead timber would otherwise be almost as valuable as if 

 living. 



CONIFEROUS TREES. 



Sawyers. — One of the most striking examples of the destruction or 

 deterioration of the wood of dying and dead timber, familiar to all 

 lumbermen, is the injury to fire-killed and storm-felled pine, fir, 

 spruce, etc., caused by boring larvae known as "sawyers." These 

 borers hatch from eggs deposited by the adult beetles in the bark of 

 the dying trees, and after feeding on the inner bark for a time they 

 enter the solid wood and extend their large burrows deep into the 

 heartwood. Fire-killed white pine is especially liable to this injury, 

 and is often so seriously damaged within three or four months during 

 the warm season as to reduce the value of the timber 30 to 50 per cent. 

 The shortleaf, loblolly, and Ibngleaf pines of the Southern States are 



« Revised extracts from Bulletin No. 58, Part V, Bureau of Entomology, U. S. 

 Department of Agriculture, 1909. 



64138°— Cir. 127—10 



