392 



YEARBOOK OF THE DEPARTMENT OF AGRICULTURE. 



cypress, and like soft wood is especially liable to injury by ambrosia 

 beetles, while the heartwood is sometimes ruined by a class of round- 

 headed borers known as sawyers. Yellow poplar, oak, chestnut, gum. 



FIG. 54. Work of round-headed borer, Callidium antennatum, in white pine bucket staves from 

 Hampshire: a, where egg was deposited in bark; b, larval mine; c, pupal cell: (I, exit in barl 

 e, adult, slightly reduced. (Original.) 



hickor} r , and most other hardwoods, are, as a rule, attacked by species 



of ambrosia beetles, sawyers, and timber worms different from those 



infesting the pines, there being but very few species which attack both. 



Mahogany and other rare and valuable woods imported from the 



