30 SOME INSECTS INJURIOUS TO FORESTS. 



Beginning with the first part of October, the infested trees should be 

 felled and the bark removed from the main trunk and burned, these 

 operations to be completed by the first part of the following May. 



If all of the trees within a given area can not be thus felled and 

 treated, the work should be concentrated on the larger clumps and 

 patches of infested trees. 



The cost per tree for cutting, barking, and burning the bark will 

 range from about 30 cents to $1, depending on locality and accessi- 

 bility. 



Summer cutting, except in regular logging operations, is undesir- 

 able, since the cutting of a few trees in the midst of a large forest may 

 attract the insects from a long distance, and thus result in extensive 

 depredations in bodies of timber which it is most desirable to protect. 



TRAP TREES. 



In sections where it is known that the beetle is killing some of the 

 timber, trap trees should be provided in June and August. Ordi- 

 narily, 4 or 5 inferior living trees within each section, on which there 

 is evidence of the work of the beetle, should suffice. 



Trap trees should not be prepared unless it is reasonably certain 

 that the bark will be removed and burned before the broods of the 

 beetles develop and emerge, otherwise such trees may contribute to 

 the destruction of a larger amount of timber. 



STORM-FELLED OR LIGHTNING-STRUCK TREES. 



Storm-felled and lightning-struck trees are a menace to a healthy 

 forest within the distribution of this insect, since they serve as breed- 

 ing places and centers of infestation. Therefore, whenever practi- 

 cable, such trees should be watched, and if found infested with broods 

 of this beetle, they should be treated as recommended for infested 

 and trap trees. 



PUBLICATIONS RELATING TO THE WESTERN PINE-DESTROYING 



BARKBEETLE. 



1876. LeConte, J. L. — The Rhynchophora of America North of Mexico. Proc. Am. Philos. 

 Soc, Vol. XV, Dec, p. 386. Species described. 



1890. Dietz, W. G. — Notes on the species of Dendroctonus of Boreal America. Trans. Am. 

 Ent. Soc, Vol. XVII, p. 32. Revision notes. 



1899. Hopkins, A. D.— Preliminary Report on the Insect Enemies of Forests in the North- 

 west. Bui. No. 21, n. s., Div. Ent., U. S. Dept. Agric, pp. 13-15. First notes on 

 habits. 



1904. Hopkins, A. D. — Catalogue of Exhibits of Insect Enemies of Forests and Forest 



Products at the Louisiana Purchase Exposition, St. Louis, Mo., 1904. Bui. No. 48, 

 Div. Ent., U. S. Dept. Agric, p. 18. Character of work described. 



1905. Currie, R. P. — Catalogue of the Exhibit of Economic Entomology at the Lewis and 



Clark Centennial Exposition, Portland, Oregon, 1905. Bui. No. 53, Bur. Ent., 

 U. S. Dept. Agric, pp. 74 et seq. Reprinted from Bui. 48. 





