ILLUSTRATIONS. XV 



Pnge. 



Fig. 74. The eastern spruce beetle: Old galleries marked on surface of tree 119 



75. Balsam fir chips, showing annual growth, indicating dates of death of 



spruce trees 121 



76. Trees girdled by different methods 124 



77. The eastern spruce beetle: Distxibution map 125 



78. The Engelmann spruce beetle {DendrocUmus engelmanni): Egg gallery 



and eggs in living bark 126 



79. Er^elmann spruce evidently killed by Engelmann spruce beetle 



about 1853-6 128 



80. Engelmann spruce timber e\-idently killed by Engelmann spruce 



beetle and subsequently partially burned by fire 129 



81. Average-sized Engelmann spruce killed by fire and by the Engel- 



mann spruce beetle 130 



82. The Engelmann spruce beetle: Distribution map 131 



83. The Alaska spruce beetle (Dendroctonus borealis) : Adult 132 



84. The Alaska spruce beetle: Distribution map 133 



85. The Sitka spruce beetle {Dendroctonus obesus) : Adult 134 



86. The Sitka spruce beetle: Distribution map 135 



87. The redwinged pine beetle {Dendroctontis rufipennis), adult; the 



lodgepole pine beetle (Dendroctonus murrayanx), larva 136 



88. The redwinged pine beetle: Distribution map 137 



89. The lodgepole pine beetle (Dendroctonus murrayanx): Distribution 



map 139 



90. The Allegheny spruce-beetle (Dendroctonus punctatus) : Adult 140 



91. The Allegheny spruce beetle : Distribution map 140 



92. The European spruce beetle (Dendroctonus micans) : Adult 142 



93. The European spruce beetle : Egg galleries and larval chamber 143 



94. The European spruce beetle : Distribution map 145 



95. The black tm-pentine beetle (Dendroctonus terebrans): Adult 147 



96. The black turpentine beetle: Distribution map 152 



97 . The red turpentine beetle ( Dendroctonus valens) : Adult 154 



98. The red turpentine beetle : E^ galleries and larval chamber 155 



99. The red turpentine beetle : Work in bark at base of tree 157 



100. The red turpentine beetle: Basal wound in Uving tree, resulting from 



primary injury by this species 158 



101. Western yellow pine showing work of the red tiupentine beetle 159 



102. The red turpentine beetle : Distribution map 164 



