HOUSEHOLD AND CAMP INSECTS 



73 



to doors or other means of entrance, to see that there is no possi- 

 bility of insects entering through an unsuspected crevice. Before 

 replacing the contents of the vault, wood, papers or other materials 

 likely to be infested should be mqs,t carefully examined and, if 

 necessary, thoroughly heated or repeatedly fumigated with some 

 gas. Great care should be exercised to prevent the reinfestation 

 of any such place. It is even more difficult to control this pest 

 in buildings, since if it becomes abundant nothing can be done 

 aside from installing brick, stone or concrete foundations. This 



Fig. 39 White ants: a, adult male from above; b, posterior extremity of the same 

 from below; c, the same of the female; d, male seen from the side; e, side view of the 

 abdomen of the female; /, tarsus showing the segments and the claw; a, d, e, are en- 

 larged; b, c, f, greatly enlarged. (After Marlatt, U. S. Dep't Agr. Div. Ent. Bui. 4. 

 n. s. 1896) 



form of construction is especially advisable in warmer sections 

 of the country. Where books, papers and exposed woodwork only 

 are infested, thorough and protracted fumigation with hydrocyanic 

 acid gas, described on pages 74-77, may be advisable. 



Powder Post Beetles 



This name is applied somewhat indiscriminately to small insects 

 which inhabit well-seasoned, hard woods, sometimes nearly riddling 

 them, and produce piles of fine, powdery borings. Furniture, 

 flooring, timbers, tool handles and almost any well-seasoned, hard 

 wood may be invaded by these insects. They confine their opera- 

 tions very largely to the sapwood. One of the commonest of these 

 pests is a slender, dark-brown or nearly black beetle 94 (figure 40) 



94 Lyctus unipunctatus Herbst. 



