44 BULLETIN 1490, IT. S. DEPARTMENT OF AGRICL T LTURE 



This bulletin presents facts which will aid in determining the 

 nature and cause of defects caused by insects, gives recommendations 

 for avoiding preventable injury, and discusses the types of defects 

 which are not preventable. Of course it is not intended to super- 

 sede previous classifications of timber and lumber, based on defects 

 other than those due to insects. 



The principal damage comes under two types of defects, desig- 

 nated as wormholes, with no living worms or decay, and powder 

 post. 



Sound wood can be utilized where the lower price offsets the lower 

 grade and the defect is not objectionable. There will be no exten- 

 sion of the damage after -the wood is dry or seasoned. Sound, wormy 

 chestnut even can be exported with no fear of further damage from 

 the insects which caused this defect to the wood of the tree when 

 living. 



Powder-posted stock can not be safely utilized because the damage 

 is continuous in the seasoned and finished product and will not only 

 cause further damage but will be a menace to other hardwood stock 

 stored near by. 



LITERATURE CITED 



(1) Betts, H. S. 



1917. the seasoning or wood. U. S. Dept. Agr. Bui. 552, 28 p., illus. 



(2) Beown, H. P. 



1913. pith-bay flecks in wood. U. S. Dept. Agr., Forest Serv. Circ. 



215, 15 p., illus. 



(3) Brunner, J. 



1914. THE SEQUOIA PITCH MOTH, A MENACE TO PINE IN WESTERN MONTANA. 



U. S. Dept. Agr. Bui. Ill, 11 p., illus. 



(4) 



1915. dougias ftr pitch moth. U. S. Dept. Agr. Bui. 255, 23 p., illus. 



(5) 



1915. the Zimmerman pine moth. U. S. Dept. Agr. Bui. 295. 12 p., 

 illus. 



(6) Burke, H. E. 



1905. black check in western hemlock. U. S. Dept. Agr., Bur. Ent. 

 Circ. 61, 10 p., illus. 



1910. INJURIES TO FOREST TREES BY FLAT-HEADED BORERS. XL S. Dept. 



Agr. Yearbook 1909: 399-415, illus. 



(8) Chamberlin, W. J. 



[1924]. FOREST ENTOMOLOGY. AN ACCOUNT OF THE INJURIOUS AND BENE- 

 FICIAL INSECTS WHICH AFFECT FOREST AND SHADE TREES. 2 V. 



Ann Arbor, Micb. [Minieograpbed.] 



(9) Craighead, F. C. 



1919. protection from the locust borer. U. S. Dept. Agr. Bui. 1ST, 



12 p., illus. 



1920. direct sunlight as a factor in forest insect control. Ent. Soc. 

 Wash. Proc 22 : 106-108. 



protection of mesquite cordwood and posts from borers. U. S. 

 Dept. Agr. Farmers' Bui. 1197, 12 p.. illus. 



experiments with spray solutions for preventing insect injury 

 to green logs. U. S. Dept. Agr. Bui. 1079. 11 p. 



1923. a brief summary of the budworm investigations IN CANADA. 

 Jour. Forestry 21 : 134-138. 



(10) 



1920. 



(11) 





1921. 



(12) 





1922. 



(13) 





