POWDER-POST DAMAGE BY LYCTUS BEETLES. 9 



with three pairs of legs, and Avith the tip of the body curved under 

 toward the head. Upon reaching maturity as a larva it excavates a 

 cell at the end of its burrow (fig. 9), and in this transforms to the 

 pupa (fig. 10). Later the pupa changes to the adult beetle (fig. 11), 

 which can fly in search of suitable places to lay its eggs. 



Fig. 5. — Powder posted oak file case, showing exit holes of adult beetles ; work of 

 Lyctus planicolUs. (Original.) 



Seasoned wood is attacked by these beetles because the chemical 

 changes which take place in the process of seasoning render the nu- 

 tritive substances in the wood, such as sugar and starch, especially 

 suitable as food for the development of the young or larval stage. 



Each female beetle deposits many eggs,^ and many females oviposit 

 in a single piece of wood, so that the combined work of their nu- 



1 A large female of Lyctus planicolUs Lee, about one-fourth inch in length, that was 

 dissected contained ovaries as two separate, elongate ovate clusters one-tenth inch in 

 length, one of which was .nbout one-third the size of the other. These ovaries took up 

 most of the space of the abdomen. The eggs were arranged in rows so as to have the ap- 

 pearance of being braided. The mature ovuh's, or fully formed eggs, are pointed at one 

 end and rounded at the other, with the rudimentary strand present at the rouuded end. 

 The egg surface is apparently granular. At least 40 eggs were in the larger mass. 

 R11fin° — ■Rnll 77S — 17 2 



