INSECT INJURIES TO FOREST PRODUCTS. 



397 



their work; therefore, it is important that all such material should be 

 removed previous to the construction of buildings to prevent danger. 

 The creosote treatment of frame timbers would doubtless prevent the 

 attack of powder post borors. 



WOODWORK IN WAGONS. KI KMTUKK, ETC. This is often seriously 

 damaged or destroyed by powder post borers (rig. 50), which are intro- 

 duced by the use of infested wood, in which the}' continue to work 

 regardless of paint and subsequent external treatment. 



STAVES AND HEADINGS OF BARRELS CONTAINING ALCOHOLIC LIQ- 

 UIDS. These are liable to attack by ambrosia beetles (figs. 43, &, and 



FIG. 55. Work of the hemlock tanbark destroyer, Dinoderus substriatus: a, bark less than three years 

 old, uninjured; h, bark over three years old; c, surface of inner bark eaten by adults; d, inner por- 

 tion destroyed by larva; and adults; e, adult, natural size. (Original.) 



45, ), which are attracted by the moist condition, and possibly by 

 the peculiar odor of the wood, resembling that of dying sapwood of 

 trees and logs, which is their normal breeding place. There are many 

 examples on record of serious losses of liquors from leakage caused by 

 the beetles boring through the staves and headings of barrels and casks 

 in cellars and storerooms. 



The condition, in addition to the moisture of the wood, which is 

 favorable for the presence of the beetles is proximity to their breeding 



