Facts about the Mountain Pine Beetle in B.C.
Beetle Biology

Dendroctonus ponderosae is the Latin name for mountain pine beetle. The average life span of the mountain pine beetle is one year. The mountain pine beetle larvae live under the bark during the winter. They continue to feed in the spring and transform into pupae in June and July. The adult mountain pine beetle emerges from the tree in the summer and early fall. The mountain pine beetle transmits a fungus that stains the tree's sapwood blue.

Beetle Impacts

  • By 2004 the mountain pine beetle had affected about seven million hectares of B.C. forests.
  • The mountain pine beetle infestation will have economic implications in the future for 30 communities around the province.
  • The livelihood of about 25, 000 families in British Columbia have been impacted by the beetle infestation.

Contributing Factors

  • The mountain pine beetle prefers mature timber. The lodgepole pine trees are classed as being mature after 80 years.
  • We have three times more mature lodgepole pine now than 90 years ago because equipment and techniques for protecting forests against forest fires have improved greatly.
  • Cold weather kills mountain pine beetle larvae. Sustained temperatures of -25 Celsius in the early fall or late spring, and -40 Celsius in the winter are needed to control populations.
  • Hot and dry summers leave pine drought-stressed and more susceptible to attack.

Infestation Information

  • The current mountain pine beetle infestation can be traced back to 1993.
  • A hectare is considered infested if there are more than 10 beetle attacked trees.
  • The mountain pine beetle outbreaks happen anywhere: in mountain subdivisions, backyards, municipal parks as well as wilderness areas.
  • Mountain pine beetles have been found as far north as Fort St. James, as far east as Cranbrook, as far west as Houston and as far south as Manning Park.
  • It is impossible to predict the direction and spread rate of the mountain pine beetle.
  • There are three stages in a mountain pine beetle attack: green, red and grey.
  • The mountain pine beetle has been found in 12 western American states and Mexico as well as B.C. and Alberta.

Western Pine Beetle, A Landowner's Guide
By D.A. Leatherman, D.K. Grant, C.T. Carmichael

Quick Facts

Ponderosa pine trees that are not growing vigorously due to old age, crowding, poor growing conditions, marginal sites, drought, fire, root disease, mechanical damage, mistletoe infection and other causes are most likely to be attacked.

WPB typically produce two generations per year. The adults generally emerge in May to attack host trees and a second generation of adults emerges in September to attack additional trees.

Pursuant to label directions, the best way to prevent infestation of prized ornamental trees is to spray with carbaryl or permethrin products, specifically labeled for bark beetles, in April. Spraying can be done either by landowner or service contractor.

For a long term remedy thin susceptible stands. Leave wellspaced healthy trees.

Treat infested trees by cutting them down and burning, chipping, burying, or debarking the infested wood priorto beetle emergence. These steps eliminate a source of infestation for other trees.

Signs and Symptoms of Pine Beetle Attack
  • Multiple popcorn-shaped masses of resin, called "pitch tubes," on the trunk where beetle tunneling begins. Pitch tubes may be brown, pink or white.
  • Boring dust in bark crevices and on the ground immediately adjacent to the tree base.
  • Evidence of woodpecker feeding on trunk. Patches of bark are removed and bark flakes lie on the ground or snow below tree.
  • Foliage turning yellowish to reddish throughout the entire tree crown. This usually occurs six to 10 months after a successful WPB attack.
  • Presence of live WPB (eggs, larvae, pupae and/or adults) as well as galleries under bark. This is the most certain indicator of infestation. A hatchet for removal of bark is needed to check trees correctly.
  • Bluestained sapwood. Check at more than one point around the tree's circumference.
Infested Trees
  • Once WPB infests a tree, nothing practical can be done to save that tree.
  • Under epidemic or outbreak conditions, enough beetles can emerge from an infested tree to kill several same-sized trees the following year.
  • Ips and related beetles that emerge early in summer often are mistaken for western pine beetle, leading to early reports that "WPB is flying." Be sure to properly identify the beetles you find associated with your trees.
  • Trees from which WPB have already emerged (look for numerous round, pitchfree exit holes in bark) do not need to be treated.
  • The direction and spread rate of a beetle infestation is impossible to predict. However, attacked trees usually are adjacent to or near previously killed trees.
Control

Logs infested with WPB can be treated in various ways to kill developing beetles before they emerge as adults in summer. Currently infested trees should be felled, limbed and bucked into smaller logs for easier handling. Logs may be burned, preferably in the fireplace, to kill the larvae under bark. They could also be debarked, buried under 8 inches of soil, or chipped. In some cases, hauling infested logs to "safe sites" a mile or more from susceptible tree hosts also is practiced. Following beetle emergence, wood can be used without threat to other trees.