45 



INJURY BY BARK-BEETLES TO PINE AND OTHER CONIFERS IN 



THE NORTHWEST. 



CASE 52. 



286. The Mountain Pine Dendroctonus (Dendroctonus n. sp.). 



Attacks living, injured, and recently felled mountain or silver pine, sugar pine, 

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

 destruction to the best timber. 



Exhibit: Adults; work of adults and larvae in bark; surface of wood showing 

 characteristic marks of work. 



287. The Douglas Spruce Dendroctonus (Dendroctonus 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. 



Exhibit: Adults; gallery of adult and mines of young larvae in bark; inner bark 

 of tree showing characteristic appearance of larval mines. 



288. The Redwood Bark-Beetle ( Phlceosinus sequoia; Hopk.). 



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

 fornia to northern Washington. Very common in redwood. 



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



289. The Lawson Cypress Bark-Beetle (Phlceosinus cupressse 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 and larval galleries. 



INJURIES BY AMBROSIA OR TIMBER BEETLES. 



CASE 53. 



290. The Apple "Wood-Stainer (Pterocyclon mali Fitch.). 



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

 sity of w T oods. It has proven very injurious to the wood of girdled cypress trees 

 and sawed mahogany lumber. In its work in mahogany it is accompanied by the 

 oak wood-stainer (Pterocyclon fasciatum). a closely allied species with similar habits. 



Exhibit: Adults; cypress lumber showing pin-hole defects caused by adults; 

 mahogany lumber seriously injured by the apple wood-stainer and oak wood-stainer; 

 cross section of mahogany plank, showing single gallery of the oak wood-stainer. 



291. The Pan-American Platypus (Platypus compositus Say). 



A timber beetle causing injury to the wood of a great variety of trees and the prin- 

 cipal cause of pin-holes in cypress. It attacks girdled trees before cutting. 



Exhibit: Adults; cypress lumber showing injury in sapwood (pin-holes usually 

 accompanied by staining). Cypress lumber showing injury to heartwood (pin-holes 

 not accompanied by staining). 



292. The Sugar-Cane Ambrosia Beetle (Xyleborus n. sp. ). 



An extremely common species throughout the southern United States, West 

 Indies, and Mexico. It attacks a great variety of woods and is also an enemy of 

 sugar-cane, excavating its galleries in living stalks. 



Exhibit: Adult; injury to wood of cypress logs after cutting and before being 

 sawed, showing entrance galleries on surface of wood and galleries in sapwood; 

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

 caused by entrance of beetles at end of logs. 



