The Ministry of Forests, Lands and Natural Resource Operations is implementing its Williams Lake Beetle Management Unit 2016 Treatment Plan to minimize the spread of Douglas-fir beetles on Crown land in the Williams Lake area.

Populations of Douglas-fir beetles are currently higher than normal in parts of the Cariboo Region. According to the ministry’s latest mapping data (based on aerial surveys conducted in the summer of 2016), the beetles killed 81,223 cubic metres of timber in the Cariboo-Chilcotin Natural Resource District in 2015.

Douglas-fir beetles normally attack small groups of trees. A significant infestation will weaken and eventually kill a tree over the period of a year. The shallow tunnels etched into the underside of the bark (called ‘galleries’) are created by the beetle adults and larvae as they feed on the wood of an infested tree.

Douglas-fir beetle infestations tend to be cyclical and the last major outbreak in the Cariboo-Chilcotin Natural Resource District peaked in 2008, covering about 68,550 hectares. The volume of timber killed by the Douglas-fir beetle in the Williams Lake Timber Supply Area that year was about 172,534 cubic metres.

The current infestation has not yet reached the size of the 2008 outbreak, but the ministry’s forest health professionals are acting quickly to limit the damage that beetles will cause over the next two years. The ministry is working closely with forest licensees, the Williams Lake Community Forest and other local stakeholders to co-ordinate treatments in high-priority areas.

The treatment plan for the Williams Lake area will run until March 2017 and includes the following activities:

• The anti-aggregative pheromone methyl cyclo hexenone (MCH) will be used to prevent or disrupt Douglas-fir beetle attacks. This naturally occurring pheromone can successfully repel the beetles from vulnerable areas and also help protect small stands of trees near parks, protected areas, campgrounds, residential properties or old growth management areas. In some cases, the application of this pheromone has reduced Douglas-fir beetle attacks by over 90%.
• “Trap trees” will be established to mimic Douglas-fir trees that have been blown down by wind. A select number of large-diameter trees will be cut down and left lying on the ground to attract adult beetles. These trap trees are more successful in attracting adult beetles than standing trees and therefore can greatly reduce the number of attacks on healthy Douglas-fir trees nearby. Once adult beetles and larvae are established within a trap tree, the tree is taken to a mill where the beetles and larvae either perish in the milling process or are destroyed on site.
• “Sanitation” harvesting (i.e., cutting down and removing individual trees where live beetles are present) is also an effective way to reduce Douglas-fir beetle populations. By harvesting standing trees where beetles are present, it’s possible to reduce their current and future populations and help stop them spreading to neighbouring stands of healthy trees. Residents of Williams Lake and the surrounding area may see loggers using helicopters or skidders to extract these trees.
• Where appropriate and if no other practical options are available, some infested trees may be cut down and burned on site.
• Funnel traps will also be deployed around mill yards and log storage areas to capture adult beetles.

The Ministry of Forests, Lands and Natural Resource Operations is committed to reducing the spread of Douglas-fir beetles in the Cariboo-Chilcotin Natural Resource District and limiting their negative impacts on the mid-term timber supply, wildlife habitat, recreational opportunities, wildfire risks and the natural beauty of the region.

Quick Facts:

• When Douglas-fir beetles attack, the needles of affected trees change colour in stages. The rate of colour change is highly variable, but a pale green or yellow colour indicates that the tree has been attacked recently. Bright red needles generally indicate that the tree was attacked the previous year and brown trees with sparse foliage generally indicate that the tree has been dead for two or three years.  A grey tree has lost all its needles and this colour usually indicates that the tree has been dead for more than two years.
• The Williams Lake Timber Supply Area contains 3.24 million hectares of forest, with 1.83 million hectares considered to be available for timber harvesting.

Learn More:

Read more about Douglas-fir beetle management or download a guide to managing Douglas-fir beetles on private property at: http://www2.gov.bc.ca/gov/content/industry/forestry/managing-our-forest-resources/forest-health/forest-pests/bark-beetles/douglas-fir-beetle/management