POWDER-POST DAMAGE BY LYCTUS BEETLES. 



11 



The larviie remain dormant or active in the wood, accordino; to the 

 temperature of the phice where stored, and in consequence infestation 

 in wood stored in cold phices may pass unnoticed. If the wood is re- 



FiG. 7. — Egg of a powder-post beetle, Lyctus planicollis, in pore of wood on radial 

 section of ash ladder-rung stock ; pore opened to show egg. Highly magnified. 

 (Snyder.) 



moved from outdoors, open storage sheds, or other 

 phices which are cold in winter, to the dry kiln, 

 the dormant larvae start to work in the wood, as 

 shown by the ejection of boring dust or powder. 

 Handling or jarring infested wood appears tempo- 

 rarily to stop the activity of larvae contained in it. 

 In general, the adults or beetles are active be- 

 tween the first of March and the last of July at 

 Washington, D. C. (about latitude 39° and longi- 

 tude T7°, and practically at sea level), but the 

 period varies according to the species, the tem- 

 perature of the storerooms, and the geographical 

 location. According to the senior author, the vari- 

 ation due to latitude, longitude, and altitude from a date at Wash- 

 ington, D. C, will be approximately four da^^s for each degree of 

 latitude, 5° of longitude, and 400 feet of altitude, being earlier in 

 the season southward, westward, and descending. The number of 

 adult beetles that might be active and deposit eggs after the last 

 of July at Washington, D. C, is so insignificant that practically 

 no damage is done by them. Therefore the danger of attack would 

 be over relatively earlier at parts south of Washington and west- 

 ward, and later northward. The approximate dates of flying and 



Fig. 8. — Larva of a 

 powder - post 

 beetle, Lyctus 

 planicollis. En- 

 larged. (Chitten- 

 den.) 



