, ILLUSTRATIONS. XV 
Page. 
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 : Distribution map. 125 
78. The Engelmann spruce beetle (Dendroctonus engelmanni): Egg gallery 
and eggs in living bark 126 
79. Engelmann spruce evidently killed by Engelmann spruce beetle 
about 1853-6 128 
80. Engelmann spruce timber evidently 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 red winged pine beetle (Dendroctonus rufipennis), adult; the 
lodgepole pine beetle (Dendroctonus murrayanse) , larva 136 
88. The red winged 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 turpentine 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: Egg 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 living tree, resulting from 
primary injury by this species 158 
101. Western yellow pine showing work of the red turpentine beetle 159 
102. The red turpentine beetle : Distribution map 164 
