Monitoring non-target impacts of the Early Intervention Strategy - December 14, 2015

Posted on December 14 2015

As discussed in my last blog entry, the team is researching the use of Btk, Mimic and pheromones to target small, newly rising populations of spruce budworm larvae as a key component of the spruce budworm Early Intervention Strategy. Pheromones occur naturally, they are unique to each insect, and they trigger behavioural changes in members of the same species. Pheromones pose no risk to humans or other animals. They are used to lure or attract insects to traps, and they can be used to disrupt mating cycles.

Our studies also give us the opportunity to monitor and evaluate the impact of our strategy on the surrounding forest organisms (such as insect predators that can help with additional control of spruce budworm) as well as other animals such as birds, fish and wildlife.

In late spring of this year, we used a single application of Mimic near Edmundston and two applications of Btk near Campbellton. To assess the environmental impacts of these compounds we sampled water in the treatment areas (near Dalhousie and Edmundston) before and after treatment.

The process we followed was similar to that used in Quebec for the last two decades: we established a background concentration prior to application of Mimic and Btk followed by water samples taken two days post-treatment and again two weeks post-treatment. These samples revealed that at no time was Mimic detectable in local rivers in the Edmundston area. The Dalhousie water samples were also taken two days post-treatment, and again two weeks post-treatment, and they revealed the same levels of Btk, or levels well below threshold. We also did water sampling after two months post-treatment. Those results will be available in the coming weeks and we will finalize our report at that time.

It’s important to note that Btk occurs naturally in water. It is only toxic to caterpillars due to their unique gut chemistry. The water sampling results show that environmental exposure to these compounds is very low, with minimal effects on non-target species. Our results are consistent with Health Canada’s approval that these are safe for use in Canada. 

On December 3, 2015, I’m pleased to report that I shared these results with municipal, regional, aboriginal community leaders from the Campbellton area. 

Branch sampling for spruce budworm.

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