204 MISC. PUBLICATION 273, U.S. DEPT. OF AGRICULTURE 



little economic importance. Most of them confine their attacks 

 to the sapwood of the hardwoods, but a few species attack pine 

 and Douglas-fir and occasionally do some damage. A few work in 

 finished products and are extremely destructive on account of their 

 ability to reinfest wood repeatedly until it is completely destroyed 

 and to attack any exposed surfaces of furniture, flooring, and sills, 

 and thus establish themselves in utilized wood products. 



Figure 98. — Wood showing holes made by Lyctus beetles. (Snyder.) 



The Lyctus beetles (75, 14-3) are probably the most dangerous 

 and destructive members of this group (fig. 98). The adults are 

 small, flat, slender, dark-brown beetles about 1/ 8 to 3 / 16 inch long. 

 Eggs are laid in the pores of the wood, and the larvae bore only 

 in the sapwood of various hardwoods, reducing it to a flourlike 

 powder. The insects pass the winter as larvae. Pupation occurs in 

 the spring, and the new adults appear early in the summer. In 

 heated buildings development is hastened, and under such condi- 



