finished products, ratlier tlian on the producer of the crude product, 

 since it is only after tlie wood is seasoned, and often some years after 

 it is taken from the tree, that it is seriously affected. The principal 

 losses result from injury to old hickory, ash, oak, and other dry hard- 

 wood lumber ; handles, spokes, and other sapwood material used in 

 vehicles of various kinds ; ornamental woodwork, furniture, inside hard- 

 wood finishings, floors, joists, and frame timbers ; inside rustic work, 

 hoop-poles, bamboo, wood specimens in museums, old tanbark, and 

 many other similar articles. In manj' cases the affected articles are 

 not only rendered worthless for the purposes for which they are intended, 

 and in the aggregate cause direct financial loss amounting to hundreds 

 of thousands of dollars, but in certain cases may be a menace to human 

 life, as in weakened construction timbers in floors, frames, bridges, and 

 wood material of vehicles, etc. Indeed, we have evidence of a railroad 

 wreck in which many lives were lost, due to powder-post injury to the 

 principal construction timl)ers. 



CAUSED BY INSECTS. 



The injury with the consequent losses mentioned is the work of sev- 

 eral kinds or s]iecies of insects which have the peculiar habit of burrow- 

 ing into seasoned wood in quest of 

 their natural food supply of nutritive 

 substances in the wood, which is ap- 

 parently rendered especially attractive 

 b}' the loss of moisture and the chem- 

 ical changes brought about by the sea- 

 soning process and the increased age 

 of the dry material. 



Cliaracter of the insects. — The adults 



Fiii. 1.— A i)OW(k'r-post beetle (ii/c^ws ;</((/(- . c i • i 



icollis): a. larva: /;, adult: f, pupa : (/.leg OY Winged lorms ot thlS claSS ot mSCCtS 



of larva; line to riKht of adult represents .^j-C Small, slender Or stout, brOWnish 

 natural length (Chittenden). i • i 



to nearly black beetles, which upon 

 emerging from the wood where they breed and pass the winter, fly or 

 crawl about in search of suitable wood material in which to deposit 

 their eggs.^ 



Habits and life Jiistory. — The different species vary in their habits 

 and life history, from the egg to the adult, but in general that of the 

 true powder-post beetles is as follows : The winter is passed in the 

 wood. The eggs are deposited under normal conditions soon after 

 activity commences in the spring, while in store-houses and buildings 

 kept warm and dry they may continue their activity through the year 



1 Teclinically the insects wliicli have tfiis peculiar habit belong to the order 

 Col('0))tera, and chieHy to the families Lyctid;e, Ptinida', and Bostrichida\ By 

 far the larger part of the injury is caused by species of the genus Lyctus, of wliich 

 there are several forms. 



