244 



WOOD AND FOREST. 



Fig-. 94. Work of Round-Headed and 

 Flat- Headed Borers in Pine: a, Work 

 of ro-jnd-headed borers, "sawyer," Mono- 

 hamnus sp.; , Ergates spiculatus\ c, Work 

 of flat-headed borer, Buprestis, larva 

 and adult. [Agric. Tear Book. 1904, 

 Fig-f46, p. 385.] 



The pine sawyers are 

 among the most trouble- 

 some pests in the mill 

 yard, and their large, 

 white larvae often do 

 much damage to logs by 

 eating great holes thru 

 their solid interior. While 

 burrowing in the wood 

 the larvae make a pecu- 

 liar grating sound that 

 may be heard on quiet 

 nights at a considerable 

 distance. This is a fa- 

 miliar sound in the lum- 

 ber camps of the North, 



and has probably given rise to the name of the pine sawyers by which these 



insects are known. (Forestry Bulletin, No. 22, p. 58.) 



Powder-post beetles, Fig. 96. This is a class of insects representing 



two or three families of beetles, the larvae of which infest and convert into 



fine powder many different kinds of dry and seasoned wood products, such 



as hickory and ash handles, wagon spokes, lumber, etc., when wholly or in 



part from the sap-wood of trees. Oak and hemlock tan-bark is sometimes 



injured to a great extent, and the structural timbers of old houses, barns, 



etc, are often seriously injured, while hop poles and like products are at- 



tacked by one set of these insects, the adults of which burrow into the wood 



for the purpose of 



depositing their 



eggs. ( Hopkins, 



Forestry Bulletin 



No. 48, p. 11.) 



Timber worms, 



Fig 97. This class 



of true wood-bor- 



ing "worms," or 



grubs, are the lar- 



vae of beetles. 



They enter the 



wood from eggs de- 



posited in wounds 



in living trees, 



from which they 



burrow deep into 



the heart- wood. 



Generation after 



rnav 



Fig-. 95. Hemlock Killed bv Buprestid Worms. 

 Hoquiam, Washington. U.S. Forest Service. 



