Moths contribute to tree defoliation in Burns Lake

Satin moths are not usual for the Lakes District

In the past few weeks, Burns Lake residents have noticed a significant number of satin moths, as well as a number of defoliated aspen trees. Could them both be connected?

According to Lisa Poirier, an entomologist at the University of Northern British Columbia, there may be a connection between satin moths and the defoliated aspen deaths; however, moths would likely only be one contributing factor.

“Your aspens are likely dying as a result of a combination of factors: defoliation by [satin moths] caterpillars, winter kill, too much or too little water, and even fungal diseases; all could contribute,” she said.

Poirier said the satin moth is not usual for the Lakes District. The insect was introduced into North America from Europe. It was first detected near Boston, Massachusetts, and in British Columbia in 1920.

“It has been extending its range over the years, though, and it is not very surprising to hear that it has reached the Lakes District,” she said. “Prince George had a localized but serious outbreak of satin moths in 2010, and some ornamental poplars sustained quite a bit of damage, including dead branches.”

Satin moths started showing up in larger numbers around Hazelton last year.

These moths are capable of completely defoliating trees. Severe defoliation in several consecutive years results in reduced radial growth of stems, branch mortality, and some tree mortality. However, Poirier said the defoliated aspen may still recover.

“Often, defoliated trees look dead, but will recover quite nicely later in the season or the following year, so don’t write them off too quickly,” she said. “Aspens are reasonably good at tolerating that kind of damage, unless it is quite severe, prolonged, or repeated over several years.”

“If the trees are, in fact, dead, and not just temporarily leafless, it may be that repeated years of defoliation – first by forest tent caterpillar, then by satin moth – along with other factors, have simply been too much for these trees,” she added.

According to Ken White, regional entomologist with the Ministry of Forests, Lands and Natural Resource Operations, while there is some mortality occurring, most trees attacked by the satin moth caterpillar will not die this year.

“While the caterpillars of this moth can completely defoliate trees within a year, it usually takes several years of damage to kill aspen trees,” he said. “Trees that are stressed by other factors – drought, diseases, etc. – may be killed more easily.”

“Our past winter had cold weather combined with little, or no, snow cover,” he added. “This seems to have placed added stress on some aspen stands.”

Ministry regional staff have already received numerous inquiries about satin moths this year. The ministry’s annual forest health aerial overview survey will be conducted later this summer, outlining the areas most heavily impacted by satin moth.

According to Natural Resources Canada, there is no practical way of preventing access of satin moths to trees. To help trees to better withstand defoliation, keep them healthy by watering the roots in the fall before frost sets in, applying a suitable fertilizer each spring, and watering them during prolonged dry periods in the summer.

Outbreaks of satin moths usually collapse after a year or two.


Just Posted

Missing boy was dehydrated but in good health

The boy who went missing near Mackenzie was found to be somewhat… Continue reading

All Nations Driving Academy gets $360K boost from province

Terrace-based driving school bridges gap in services for remote northwest B.C. communities

Skeena Watershed reopened for recreational pink and coho

Four sections and tributaries remain closed

Skeena-Bulkley Valley candidates react to finding Trudeau broke ethics law

The election campaign is heating up before the writ has even dropped

Parking lot rework effort begins

Work is well underway on the Downtown Parking Lot Redevelopment Plan, which… Continue reading

Disney Plus to launch in Canada in November

Analysts say latest streaming service may escalate cord cutting

Okanagan bus driver assaulted for asking patron not to smoke

59-year-old in hospital with non-life threatening injuries

B.C. sets rules for ride hailing, same minimum fee as taxis

Larger operating areas seen as threat by cab companies

Two hiking families team up to extinguish fire in B.C. backcountry

Children and their parents worked for three hours to ensure safety of the popular hiking region

Vancouver man arrested after pregnant woman’s SUV stolen, then crashed

Police are recommending charges against a 22-year-old Vancouver man

Elections Canada to assess ‘partisan’ climate change rhetoric case by case

People’s Party of Canada Leader Maxime Bernier has said climate change is not an emergency nor caused by human

Unseasonable snow forces campers out of northeastern B.C. provincial park

Storm brought as much as 35 centimetres of snow to the Fort Nelson, Muncho Lake Park-Stone Mountain Park

B.C. log export rules killing us, northwest harvester says

NorthPac Forestry says Skeena Sawmills has plenty of timber

Most Read