Some insects injurious to forests . ornia, Oregon, and eastern and western Washington, and, accordingto Doctor Hopkins, a variety occurs in Arizona and New Mexico andattacks the western yellow pine {JPinus ponderasa) and the sugar pine(Pinus lambertiana). EXTENT OF DAMAGE AND LOSSES. With our present knowledge of the destructive4 work of this is evident that a vast amount of timber has been killed by it duringthe past ten years within the range of its distribution. It is estimatedthat each year for the past two or three years, from 2 to 5 per cent ofthe matured standing bull pine tim
Some insects injurious to forests . ornia, Oregon, and eastern and western Washington, and, accordingto Doctor Hopkins, a variety occurs in Arizona and New Mexico andattacks the western yellow pine {JPinus ponderasa) and the sugar pine(Pinus lambertiana). EXTENT OF DAMAGE AND LOSSES. With our present knowledge of the destructive4 work of this is evident that a vast amount of timber has been killed by it duringthe past ten years within the range of its distribution. It is estimatedthat each year for the past two or three years, from 2 to 5 per cent ofthe matured standing bull pine timber within the section investigatedin the summer of 1905 has died as the result of its ravages. POSSIBILITIES OF PREVENTING LOSSES. With our additional knowledge of the life history and habits of thebeetle, we are able to suggest practical methods of controlling it and. Bur. Ent, V. S. Dept. Agric The Black Hills BeetK. 20 SOME INSECTS INJURIOUS TO FORESTS. EARLY HISTORY OF THE SPECIES. LeConte, in 1876, described the species under the name Dendroc-tonus brevicomis from a single specimen collected in middle , 1890, considered D. brevicomis the same as the southeasternspecies, D. frontalis Zimm. Hopkins, 1899, concluded that it wasdistinct from D. frontalis, and therefore that the old name should beretained. It appears that previous to 1899 nothing had been recorded inregard to the habits and life history of this insect, and that, therefore, the earliest records were made in 1899by Hopkins, who found it associatedwith dying sugar pine and western yel-low pine at McCloud, Cal., on April 21,1899, and the next day at Grants Pass,Oregon, with several hundred pine treeswhich had evidently died from its May 20, also, at Buckeye (near Spo-kane), Wash., many trees were found Fig. 9.—The western pine-destroying . barkbeetle (Dendroctonus brevicomis): WHICH Were dying, Or had died, a
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