It would appear that the worst of the Mountain Pine Beetle epidemic in the Central Okanagan is over, although the devastating pests are not completely gone.
Blair Stewart, with urban forestry for the City of Kelowna, says he’s hopeful that all the city’s efforts to clean up trees before the first flight of beetles every year has helped to ease the pressure locally from the province-wide epidemic.
The province’s forest health technician in this area for the ministry of forest operations, Heather Rice, agrees that generally, the Mountain Pine Beetle has moved through the Central Okanagan and is moving into new stands of pines in the south this year.
“The epidemic wasn’t as bad in the Okanagan as was predicted,” she commented. “As it was building (in the north of the province) the thinking was that we could lose 80 per cent of our pine, but less than 50 per cent has been lost.”
It is now moving away from stands which have been attacked by the beetle, and into new stands to the south.
Northern B.C. has been devastated by the epidemic, in part because of the largely even-aged, all-pine stands in the northern part of the province, while here most stands are mixed fir and pine with some spruce.
As it turns out, Rice said there will be some pine trees left in our mixed stands, and beetle populations are no longer building up here.
MPB is a native pest that naturally cycles throughout the province, but because of a series of factors— including milder winters, drought and fire-stressed trees, vast areas of aging pine trees that are vulnerable to attack and man’s suppression of wildfire—in the past decade B.C. has seen the worst-ever insect epidemic in its history.
Stewart said he is seeing the same situation in the urban forest in the valley bottom as commercial foresters are seeing in timber stands around the valley’s communities.
Where at the peak of the epidemic, city crews removed 500 trees from Knox Mountain Park, only 50 had to be removed this year, he noted.
In the Glenmore area north of the landfill, crews did take out a lot of trees this year, he said, and there are still some red-attacked trees, or trees in the second year of attack, but there are far fewer this year.
Although the insects are only the size of a grain of rice, MPB kills mature lodgepole pine trees in a year, turning the trees from green to red, and then to black or dead as the red needles fall off.
He said there are a few pockets in the centre of town where there is still an issue, such as in Lions Park in Rutland, but the city is planting 7,000 seedlings this year in Knox Mountain Park as well as other natural open public spaces, including north of the landfill.
Conifers and deciduous trees are also being planted with the assistance of a TD Greenstreets grant of $15,000 which relies on matching funding from the city.
On private property, the infestation is also lessening and Stewart said they are receiving far fewer calls from property-owners now.
He says they will continue to use the Contech verbenone anti-aggregation pheromone patches to try and protect particular trees from the beetles. They give off a pheromone that tells beetles who are flying to try and find a new tree to infest, that this tree is already full, so they won’t attack it.