Our Boreal Forests and the Spruce Bud Worms
You may be aware that there is a serious Spruce Budworm problem in the Bragg Creek area. This concern has been going on for some years and this infestation is now in dire need of attention. Redwood Meadows townsite has carried out extensive research and is planning to instigate an aerial spray in early May with a second application in June to help prevent these worms from taking over that area.
The Spruce Budworm has been known to be the most prevalent defoliator of spruce-fir forests in North America. They are extremely destructive and if unmanaged can cause trees significant mortality rates. Outbreaks typically last up to 10 years in which the caterpillars repeatedly eat the new foliage of the trees. It is important to know it takes 4-6 years of severe infestation before a tree could be killed. If an uncontrolled outbreak occurs, tree growth can be reduced by 90%.1
Their life cycle involves the SBW spending the winter as tiny larvae hibernating in the branches of the trees. In spring, the larvae emerge and begin feeding on the current years’ needles and new growth or buds. Feeding continues during May and June. Once feeding is finished the larvae or 2cm brown caterpillar will pupate and emerge as an adult greyish-brown moth
in a couple of weeks. The moths mate and the females will lay up to 200 eggs on the underside of the spruce needles. The eggs then hatch in two weeks resulting in young larvae again finding hiding places in the branches to spend the winter, thus completing their one-year life cycle.2
The pervasive SBW has adapted to extreme Canadian winters by producing its own antifreeze chemical which provides them with a seasonal cold hardiness. Now with global warming trends of milder winters the worms are no longer experiencing a die off when exposed to extremely frigid temperatures.3
Fortunately, there is a long-standing proven treatment called BTK or Bacillus Thuringiensis var. kurstaki which has been registered for use in Canada for the last 30 years. BTK is a bacterium found naturally in soils and is fatal only to moths and butterflies and has been proven safe for all other flora and fauna. It affects the targeted species for 3-5 days after which it becomes inert and hence is environmentally friendly. The Redwood Meadows townsite is working in partnership with the Forestry and Environment Specialists to administer an aerial application which has been endorsed by Health Canada and Alberta Environment and Parks. This will be administered in May and June aided by an Entomologist for timing sequences.4
The benefits of the BTK treatment have been said to last three years. In the meantime, the surrounding areas that have not been treated are still vulnerable to ongoing infestation. Perhaps the residents of Bragg Creek need to consider spraying their area with BTK because keeping our Boreal Forests healthy is important to our life style, the animal life, our well-being and economy. Good forest management is pivotal to the success of the healthy trees now and in decades to come.
By working together, residents of the Bragg Creek can tackle this infestation before the worms do significant damage to our forests and our property values. Consider sending an email to Councilor Mark Kamachi as well as our MLA Miranda Rosin, also you can “Report a Problem for Pest Control” to Rockyview County Website to let them all know how important this issue is to you and our community.
submitted by Kym Binns
Endnotes:
1. Referenced from Healthy Forest Partnership
2. Referenced from Healthy Forest Partnership
3. Referenced from U of BC Thesis and Dissertations
4. (Refer to The Redwood Meadows Website: Spruce Bud Worm)
