Forestry Branch
Mountain Pine Beetle
The mountain pine beetle, Dendroctonus ponderosae, is a bark beetle native to British Columbia, Alberta and western mountain states. The larvae of this species normally feed on lodgepole, ponderosa, sugar, and western white pines. Currently, there is a mountain pine beetle outbreak in British Columbia infesting thousands of hectares of lodgepole pine forests. Consequently, there is a large amount of pine salvage being harvested and exported from these infested forests. This presents a potential threat to Manitoba as field tests suggest that mountain pine beetle populations may be able to establish in jack pine forests. While the possibility of mountain pine beetles establishing in Manitoba's jack pine forests is not known, the epidemics of these insects which are occurring in western North America are cause for concern.
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 Larva (actual size 7 mm) |
Importation of mountain pine beetle has become an issue following the discovery in Alberta of a truckload of "debarked" cants from British Columbia found to have 25% of the bark still intact. Mountain pine beetle galleries with live larvae were found beneath the bark. There is a high probability that pine products, with bark intact, originating from infested forests of British Columbia could contain live mountain pine beetles. To date, these beetles have not been found in Manitoba.
"Pitch Tubes" indicating trunk attacks |
To identify the presence of mountain pine beetle, look for yellow pitch masses on the outer bark at the point of adult entry, red boring dust in bark crevices and long straight egg galleries that follow the grain within the inner bark. The egg galleries will be packed with boring dust and insect droppings. Adults are stout, black, cylindrical beetles. Larvae are white legless grubs with brown heads. Both are about 7 mm (1/4") in length.
Wood containing mountain pine beetles is often discolored by blue-stain fungi. While blue stained wood is undesirable to the lumber industry, demand by the log home building industry has increased for this stained salvage material, referred to as "denim" logs.
If you encounter any imported pine products with bark attached, which you suspect may harbor live mountain pine beetle, please call the Forestry Branch, at 945-7868.
