(> 



UNITED STATES DEPARTMENT OF AGRICULTURE. 



BUREAU OF ENTOMOLOGY, 

 WASHINGTON. D. C. 



FOREST ENTOMOLOGY 10. 



April 11, 1916. 



Brief Information on 

 INSECT DAMAGE TO ROUGH AND FINISHED SEASONED FOREST PRODUCTS 



IN YARDS, STOREHOUSES AND USE 

 and ITS CONTROL. 



Damage . 



The sapwood of seasoned hardwood material of all kinds, both finished 

 and unfinished and especially of hickory, ash and oak is often found up to 90% 

 ruined by what is popularly called "powder post". This is a pulverization of 

 the wood fiber by the grubs or larvae of several species of beetles. 



Material seasoned- a year or more is especially suojecx. bo at- 

 tack by these beetles. 



Evidence of Infestation. 



Fine, flour-like powder on or beneath piled or stored seasoned hardwood 

 products. Upon closer examination small holes will usually be found in the 

 surface of the wood from which the powder will fall when moved or jarred. By 

 cutting into the wood, the interior is often found converted into a mass of 

 closely packed material which readily crumbles into powder. This is held to- 

 gether by an outer thin shell and intervening fibers of sound wood. It will 

 also be found that the injury is confined to the white or sapwood, and that 

 the darker-colored heartwood is seldom, if ever, thus affected. 



Remedy . 



Material of this kind, once attacked is usually damaged beyond repair. 

 If not too far advanced and the piece is still worth saving, further damage can 

 be stopped by saturating it with kerosene. But freedom from powder post damage 

 can be attained only by observing the following rules of 



Prevention. 



(1) Inspect material in yards and storehouses annually, preferably 

 in November and February and 



(a) sort out and burn material showing evidence of powder post attack; 



(b) burn all refuse and useless sapwood material. 



(2) Classify, as far as practicable, all dry or seasoned hardwood stock into 

 (a) heartwood; (b) pure and part sapwood; (c) hickory, ash, oak, etc. 



and (d) according to number of years seasoned. 



(3) Utilize or sell the oldest stock first. 



(4) Prevent accumulation of refuse material in which the insects could breed. 



(5) Prevent introduction into lumber yards and storehouses of material in- 

 fested with powder post. 



(6) If the above precautions are not taken, treat more valuable material 

 with linseed oil or kerosene (by immersion or application with a brush) to pre- 

 vent attack. 



A. D. HOPKINS, 



Forest Entomologist. 



