INDEX OF HOST TREES 



Note. — The insects are grouped according to the part of the tree where 

 they are usually found. Sometimes insects working under the bark of the 

 trunk are also found in limbs and twigs or entering the wood. Some bark 

 borers may, in the adult stage, even feed on the needles. Insects known to kill 

 trees are preceded by an asterisk. 



Alder (Alnus spp.) — 



attacking leaves — 



caterpillars — 



Halisidota maculata, 88 



Hyphantria cunea, 88 



Hyphrantria textor, 89 



Malacosoma disstria, 94 



Malacosoma pluvialis, 95 



Notolophus antiqua, 93 



Telea polyphemus, 86 

 leaf beetle, Altica ambiens, 123 

 leaf miners — - 



Cameraria alnicolella, 116 



Phyllonorycter incanella, 115 

 sawfly, Cimbex americana, 122 

 in smaller limbs, twigs, or trunk — 

 bark beetle, Micrasis hirtellus, 39 

 bark weevils — 



Magdalis aenescens, 42 



Magdalis gracilis, 42 

 flatheaded borers — 



Agrilus politus burkei, 46 



Chrysobothris femorata, 47 



Chrysobothris mali, 47 

 twig girdlers — 



Agrilus politus burkei, 46 



Agrilus politus politus, >!6 

 in wood 



ambrosia beetles — 



Gnathotrichus alni, 185 



Xyleborinus saxeseni, 187 

 clearwing moth, Thamnosphecia ameri 



cana, 200 

 flatheaded borers — 



Acmaeodera spp., 191 



Buprestis viridisuturalis, 189 



Chrysobothris spp., 190 



Dicer ca divaricata, 190 



Dicer ca horni, 190 



Dicer ca prolongata, 190 



Polycesta spp., 191 

 powderpost beetle, Polycaon stouti, 205 

 roundheaded borers — 



Necydalis cavipennis, 198 



Prionus calif or nicus, 193 



Rosalia funebris, 198 

 sapwood weevil, Rhyncolus spp., 198 

 on twigs — 



scale, Lepidosaphes ulmi, 66 

 under bark of large trunk or branches — 

 bark beetle, -'Alniphagus aspericollis, 169 

 Alder, red (Alnus rubra) — 

 attacking leaves — 

 caterpillars — 



Malacosoma disstria, 94 



Malacosoma pluvialis, 95 

 leaf beetle, Altica ambiens, 

 in wood — 



ambrosia beetles — - 



Gnathotrichus alni, 185 



Trypodendron cavifrons, 



Xyleborus arbuti, 187 

 flatheaded borers — 



Buprestis viridisuturalis, 



Dicerca prolongata, 190 



Poecilonota spp., 191 

 roundheaded borer, Rosalia funebris, 198 

 under bark of large trunk or branches — 

 bark beetle, * Alniphagus aspericollis, 169 



123 



186 



189 



Alder, white (Alnus rhombifolia) — 

 attacking leaves — 



leaf beetle, Altica ambiens, 123 

 in smaller limbs, twigs, or trunk — 

 bark weevil, Magdalis gracilis, 42 

 flatheaded borer, Chrysobothris femorata, 



47 

 twig girdler, Agrilus politus burkei, 46 

 in wood — 



ambrosia beetle, Xyleborinus saxeseni, 187 

 flatheaded borers — - 



Buprestis viridisuturalis, 189 

 Dicerca horni, 190 

 roundheaded borer, Necydalis cavipennis 

 198 

 under bark of large trunk or branches — 



bark beetle, ■•■Alniphagus aspericollis, 169 

 Arbor vitae, giant. See Redcedar, western. 

 Arbutus. See Madrofie. 

 Ash ( Fraxinus spp . ) — 

 attacking leaves — - 

 leaf caterpillars — 



Malacosoma calif or nica, 95 

 Malacosoma constricta, 95 

 Malacosoma fragilis, 94 

 Notolophus antiqua, 93 

 Platysamia cecropia, 86 

 in smaller limbs, twigs, or trunk — ■ 



flatheaded borer, Chrysobothris mali, 47 

 roundheaded borer, Phymatodes vulneratus. 



48 

 spider mite, Tetranychus spp., 68 

 in wood — 



flatheaded borer, Chysobothris spp., 190 

 powderpost beetle, Lyctus spp., 204 

 roundheaded borer, Neoclytus caprea, 198 

 on twigs — ■ 



scale, Lepidosaphes ulmi, 66 

 Ash, Oregon (Fraxinus oregona) — 

 in seeds — 



weevil, Thysanocnemis sp., 26 

 in wood — 



carpenter worm, Prionoxi/stus robiniae, 



199 

 roundheaded borers — 



Neoclytus conjunctus, 197 

 Rosalia funebris, 198 

 under bark of large trunk or branches — 

 bark beetle, Leperisinus aculeatus, 169 

 Aspen, quaking (Populus tremuloides) — 

 attacking leaves — 



caterpillar, Malacosoma fragilis, 94 

 leaf beetle, Chrysomela tremulae, 125 

 leaf miner — - 



Phyllocnistis populiella, 116 

 Phylonorycter tremuloidiella, 115 

 in smaller limbs, twigs, or trunk- — 

 twig girdler, Agrilus anxius, 46 

 in wood — 



ambrosia beetle, Trypodendron yetusus, 



186 

 flatheaded borers — 



Buprestis confiuenta, 189 

 Dicerca prolongata, 190 

 Poecilonota spp., 191 

 roundheaded borers — 

 Xylotrechus annosus, 197 

 Xylotrechus obliteratus, 197 



