Mountain pine beetle
Dendroctonus ponderosae Hopkins (Coleoptera: Curculionidae, Scolytinae)
Orientation to pest
Mountain pine beetle, Dendroctonus ponderosae Hopkins, a native North American species, is the most destructive bark beetle of the western United States and Canada, where it occurs widely on a variety of pines, including lodgepole (Pinus contorta Douglas), ponderosa (P. ponderosa Douglas ex C. Lawson), western white (Pinus monticola Douglas ex D. Don), whitebark (Pinus albicaulis Engelmann) and sugar (Pinus lambertiana Douglas) pines. Historically, highly destructive outbreaks of this species have occurred repeatedly, decimating mature forests of such species as lodgepole pine over extensive areas. All trees above 10 cm in diameter are susceptible to attack. Beetle attacks are usually concentrated along the main trunk, from about one meter above the ground up to the middle branches. As with many bark beetles, signs of infestations include pitch tubes on the trunk, red boring dust in bark crevices, discoloration of foliage as trees die, and blue discoloration of the wood caused by several associated fungi: Grosmannia clavigera (Robinson-Jeffrey and Davidson) Zipfel, de Beer, and Wingfield; Ophiostoma montium (Rumbold) von Arx. Females dig egg galleries under the bark and lay eggs on alternate sides of the gallery. Larvae excavate short feeding tunnels at right angles to the egg gallery. Mature larvae construct pupal cells at the ends of the larval galleries, where larvae pupate and from which new adults later emerge. Most commonly there is one generation per year but there may be only one every two years in the coldest parts of the species' range. Larvae and adults are the overwintering stages.
Hosts commonly attacked
The principal hosts of this beetle are lodgepole (P. contorta), sugar (P. lambertiana), western white (P. monticola), ponderosa (P. ponderosa), and whitebark (P. albicaulis) pines, but Pinus aristata Engelmann, Pinus balfouriana Balfour, Pinus coulteri D. Don, Pinus edulis Engelmann, Pinus flexilis E. James, Pinus strobiformis Engelm., Pinus longaeva D.K. Bailey, and Pinus monophylla Torr. and Frém. have also been recorded as hosts.
Distribution
Mountain pine beetle is found throughout the pine forests of western Canada, the western United States and northern Mexico (Baja California).
 USDA Forest Service • Forest Insect & Disease Leaflet 2 |
| Figure 1. Distribution of mountain pine beetle, Dendroctonus ponderosae, in North America |
Images of mountain pine beetle
| Figure 2. Adults of mountain pine beetle, Dendroctonus ponderosae | Figure 3. Pitch tubes of mountain pine beetle during initiation of attack | Figure 4. Larvae of mountain pine beetle in their galleries |
| Figure 5. Pupae and adults (top) of mountain pine beetle; callow adult (bottom) | Figure 6. Galleries of mountain pine beetle (top) and galleries and blue staining of wood (bottom) | Figure 7. Lodgepole pines (top) killed by mountain pine beetle; view of infested pines (bottom) |
| Figure 8. Adult of Enoclerus sphegeus Fabricus, a predator or mountain pine beetle | ||
Important biological control agents related to this pest species
Natural enemies of mountain pine beetle include predaceous insects such as Enoclerus sphegeus Fabricius, Temnochila chlorodia Mannerheim, and Medetera aldrichii Wheeler; and the parasitoid Coeloides dendroctoni Cushman.
Web links for information on mountain pine beetle
- Wikipedia Article | Wikipedia, the free encyclopedia
Includes comments on implications of current massive outbreak in Canada - Fact Sheet | Colorado State University Extension
- Fact Sheet | Nevada Division of Forestry, State of Nevada
- Forest Insect & Disease Leaflet 2 | USDA Forest Service
2009 revision provides updated, more detailed distribution map - Bark Beetle Website on usu.edu | USDA Forest Service, Rocky Mountain Research Station
Articles
- Safranyik, L., A. L. Carroll, and B. Wilson. 2006. The biology and epidemiology of the mountain pine beetle in lodgepole pine, pp. 3-66. In: Safraynyik, L. and W. R. Wilson (eds.). The Mountain Pine Beetle: A synthesis of the biology, management and impacts on lodgepole pine. Natural Resources Canada, Canadian Forest Service, Pacific Centre, Victoria, British Columbia, 304 p.
- Robertson, C., T. A. Nelson, D. E. Jelinski, M. A. Wulder, and B. Boots. 2009. Spatial-temporal analysis of species range expansion: the case of the mountain pine beetle, Dendroctonus ponderosae. Journal of Biogeography 36 (8): 1446-1453.
