CATALOGUE OF EXHIBIT. 



Section I.— INSECT ENEMIES OF FORESTS IN THE NORTHWESTERN 



AND NORTHEASTERN UNITED STATES. 

 Section II. —INSECT ENEMIES OF FORESTS IN GENERAL. 

 Section III.— SPECIAL INVESTIGATIONS. 

 Section IV.— PHOTOGRAPHS. 



SECTION I. 



INSECT ENEMIES OF FOREST TREES IN THE NORTHWESTERN 

 AND NORTHEASTERN UNITED STATES. 



NORTHWESTERN STATES. 



INJURY BY AMBROSIA BEETLES. ORDER COLEOPTERA, FAMILY 



SCOLYTIL\aa. 



CASE 1. 



1. The Western Platypus {Platypus n. sp.). 



Excavates long, branching galleries in the sapwood and heartwood of injured, 

 dying, and recently felled Douglas spruce, western hemlock, and giant arbor yitae. 

 California to northern Oregon; also reported from Washington. 



Exhibit: Adult and work. 



2. Western Hemlock Wood-Stainer (Gnathotrichus sulcatus Lee). 



Excavates numerous branching galleries from a central burrow, the broods living 

 in closely joined side chambers; in the sapwood and heartwood of western hem- 

 lock, Douglas spruce, giant arbor vitae, and grand fir. California to northern Wash- 

 ington; common in hemlock. 



Exhibit: Adult and work. 



3. The Western Pine Wood-Stainer (Gnathotrichus n. sp.). 



Excavates transverse galleries in the surface of the wood and branching ones deep 

 in the sapwood and heartwood, the broods living in short side chambers; western 

 yellow pine and Douglas spruce. Cascade and Eocky Mountain region, California 

 to northeastern Washington. 



Exhibit: Adult and work. 



4. The Eastern Pine Wood-Stainer (Gnathotrichus materiarius Fitch). 

 Excavates several branching galleries from a single-entrance burrow, the broods 



living in short side chambers in sapwood and heartwood of injured, dying, and 

 recently felled pine and spruce. Eastern United States and Canada. Very common 

 and injurious. 



Exhibit: Adult and work. 



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