Douglas-Fir Tussock Moth Outbreak

The Forest Entomologist with the Thompson Okanagan Region, Ministry of Forests, Lands and Natural Resource Operations (MFLNRO) states we are experiencing the start of a Douglas-fir tussock moth outbreak throughout the region. She checked out our area a week ago and found evidence of the natural virus in the population.

If private land owners want to treat next spring, B.t.k. is a biological insecticide that is often used. She will send us a more detailed response and additional information when she is back in her office at the end of the week (middle of August 2019).

Once we receive the information from the Entomologist, we will post it to the website and let everyone know what is occurring and what options there are to deal with this issue.

The infestation of the Douglas Fir Tussock Moth is causing devastation from caterpillars around Caribou and the Eagle Point area. People are afraid that by next year the whole area’s fir trees will be dead from the caterpillars eating all the needles and the trees won’t survive. The trees around the summit centre and on Sasquatch are also infected. The caterpillars/moths are likely working their way down the mountain.

All these dead fir trees will also add to our wildfire risk.

In the past, AMCS received written (email) consent and collected $ from each property owner (about 15 – 18 property owners) who wanted their properties sprayed and received about $$20 – $30K from Regal Ridge (the land developer at the time).

AMCS hired an aerial spray company from Abbottsford to come and spray a biological virus using a helicopter (the same natural virus that kills tussock moth). About a week before the spraying was to commence the BC Ministry of Environment stepped in and said a “pesticide permit” was needed. Mark McKenney argued that the agent to be sprayed (B.t.k.) was a natural product and was not listed on either federal or provincial registries as a pesticide under the legislation, so it wasn’t a pesticide at all.

The Okanagan pesticides inspector intimidated the aerial spraying company…and they decided they would only spray over Regal Ridge land, which they agreed was not residential. The spray company did spray about 500 – 600 acres of Regal Ridge forest…and the kill results were amazing. Literally millions and millions of dead tussock moth larvae were on the forest floor. In some places the larvae were nearly a foot deep on the ground. It really wiped the moths out where we sprayed. So this works.

The MFLNRO are tracking this pest and have a 4-year plan, ending in 2021, to deal with the impact to timber resources.

This document (link below to a 57 page pdf) deals with other pests as well and their history in our area. The moth is on a 10-year cycle and can live for up to 4 years before they die off from predation or starvation.

We will inform the Anarchist Mountain community via the website and hold a general meeting that involves all affected parties (including OMEI) to see what everyone’s thoughts on this issue are to help us decide what to do for next spring.

We will have an expert conduct a talk with our community that would help increase awareness and provide steps private land owners can take to address the problem on their own properties.

We are also thinking of posting a survey online to see what the response is.

Peter Humphrey

About AMCS

Building community involvement in the preservation and enjoyment of Anarchist Mountain's natural and cultural environment
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2 Responses to Douglas-Fir Tussock Moth Outbreak

  1. Curt says:

    Its been nuts up here on Raven Hill for the past 3 summers. Last year was bad, this year far worse. How do they figure that this is a start of an outbreak when it says on their own bc gov PDF on the subject that an oubreak lasts 4 years?!
    I’ve used BTK on my fruits etc. for years.
    Much support for this project

    • Hilda says:

      On July 22, 2018 I contacted Babita Bains, MSc, RPF a Provincial Forest Entomologist at Resource Practices Branch, MFLNRORD about the Tussock Moth issue that we were (are) having on our property on Raven, so they have been aware of it since then anyway….. this is the message that I received back as a reply to my concern:

      “Thank-you for contacting us regarding your forest health question. The caterpillars appear to be tussock moths (Orygia pseudotsugata is the Latin name). We do monitor the tussock moth populations and when populations are high we do complete spray programs on public lands to reduce population levels however the populations do also collapse on their own due to natural controls (this species is native and is not an invasive species). Here is a link to more information on tussock moth and on the tussock moth homepage there are a number of different documents with various information:

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