. The Black Hills beetle : with further notes on its distribution, life history, and methods of control. Mountain pine beetle; Forest insects. 14 THE BLACK HILLS BEETLE. Trees infested with partially to fully developed broods from the latter part of August to the first of November, and during the period of inactivity, are distinguished by numerous pitch tubes over and entirely around the middle portion of the trunk and extending more or less toward the base and top. The age of the pitch tubes is indicated by their relatively moist or dry con- dition. A successful or vital infestation will be s
. The Black Hills beetle : with further notes on its distribution, life history, and methods of control. Mountain pine beetle; Forest insects. 14 THE BLACK HILLS BEETLE. Trees infested with partially to fully developed broods from the latter part of August to the first of November, and during the period of inactivity, are distinguished by numerous pitch tubes over and entirely around the middle portion of the trunk and extending more or less toward the base and top. The age of the pitch tubes is indicated by their relatively moist or dry con- dition. A successful or vital infestation will be shown by the large number of pitch tubes surrounding the entire trunk, and also by their red- dish color and general ap- pearance. An unsuccessful attack—from which the tree will recover—is indicated after the first of November by a small number of smooth whitish pitch masses scat- tered about over the trunk, confined to or toward the base; their absence on the middle to upper portion of the trunk or, if present there, their failure to completely surround it. Positive evidence as to whether or not a green- topped, pitch-marked tree is infested by living broods is determined only by cutting into the bark at different places, 4 to 8 feet from the base. This test should be made during the inactive period, when trees are being marked for cutting. Soon after activity begins in the spring, infested trees are distinguished by a pale appearance of the foliage, followed by a yellow or reddish brown color, as if killed by fire. Dead trees which have been killed by the Black Hills beetle but are no longer infested by living broods are distinguished during the summer, fall, and winter by the old dry pitch tubes on the bark and the dark reddish brown or "black-topped7; condition. The only. Fig. 4.—Work of the Black Hills beetle: a, pitch, tubes on surface of bark, much reduced; 6, same, two-thirds natural size. (Author's illustration.). Please note that these images are extracted
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Keywords: ., bookauthorhopkinsadandrewdelmar, bookcentury1900, bookdecade1900
