45 



INJURY BY BARK-BEETLES TO PINE AND OTHER CONIFERS IN 



THE NORTHWEST. 



286. The Mountain Pine Dendroctonus {Dt'iiilrortoiius n. sp. ). 



Att;ll•k^^ liviii<,', injun-il, and n-coiitly felled iiioiintain or silver jdne, sugar pine, 

 aiitl lodge-pole pine in the Northwestern States. Very connnon and capable of great 

 detit ruction to the best tind)er. 



Exiiihit: Adults; work of adults and larva- in bark; surface of wood showing 

 characteristic marks of Avork. 



287. The Douglas Spruce Dendroctonus {Dendrodoiius n. sp.). 



Attacks living, injured, and recently felled Douglas spruce and western larch. 

 Kocky Mountain region and Pacific coast. Very common and capable of destroying 

 much valuable timber. 



IvvniuiT: Adults; gallery of adult and mines of young larv;e in bark; inner bark 

 of tree showing characteristic appearance of larval mines. 



288. The Redwood Bark-Beetle {P}ikiosiiin.'< i^equo'ur llopk.). 



Attacks living, injured, and recently felled redwood and giant arborvita;. Cali- 

 fornia to northern Washington. Very common in redwood. 



ExiiiniT: Adults; surface of wood grooved by adult galleries and larval mines. 



289. The Lawson Cypress Bark-Beetle {Phlao.'^inus ciipress.r Hopk.). 

 Attacks transplanted Lawson and Monterey cypress in California. It also attacks 



redwood. 



Exhibit: Adult; section of small beetle-killed Lawson cypress, showing beginning 

 of gallery of adult in living tree; section of small Lawson cypress showing character- 

 istic grooves in surface of wood, and exit holes of beetles in bark; branch of Mon- 

 terey cypress showing grooves in surface of wood of adult antl larval galleries. 



INJTTRIES BY AMBROSIA OR TIMBER BEETLES. 



290. The Apple Wood-Stainer (Ptirociidon malt Fitch.). 



A small timlter beetle first described from the apple, but attacking a great diver- 

 sity of woods. It has proven very injurious to the wood of girdled cypress trees 

 and sawe<l mahogany lumber. In its work in mahogany it is accompanied by the 

 oak wood-stainer {Pti'rorijclonJ(txrintum).a. closely allied species with similar habits. 



Exhibit: Adult.«; cypress lumber showing pin-hole defects caused by adults; 

 mahogany lumber seriously iiijure<l by the apple wood-stainer and oak wood-stainer; 

 cross section of mahogany jilank, showing single gallery of the oak woo<l-stainer. 



291. The Pan-American Platypus {Platyjiux composUus Say). 



.\ tind)er beetle causing injury to the wood of a great variety of trees and the i>rin- 

 ci|>al cause of pin-holes in cypress. It attiicks ginlled trees before cutting. 



Exiiihit: .Vdult^"; cypress lumber showing injury in sapwood (pin-lmles usually 

 a(companie<l by staining). Cypre&s lumber showing injury to heartwood (pin-holes 

 not accompanied 1)V staining). 



292. The Sugar-Cane Ambrosia Beetle {Xylchormn. sp. ). 



An extremely cunimon species throughout the southern Uniteil States, West 

 Indies, ami Mexico. It attacks a great variety of woo<ls and is al.so an enemy of 

 sugar-cane, excavating its galleries in living stalks. 



Exhibit: Adult; injury to wood of cypress logs after cutting and W'fore being 

 sawe<l, showing entrance gixlleries on surface of woo<l ami galleries in sapwood; 

 injury to mahogany logs before, during, and after importation; injury to mahogany 

 caused by entrance of beetles at end of logs. 



