Midway, B.C. – Beetle attacks on fir trees in Southern Interior forests cause substantial damage to healthy trees and can lead to increased fuel accumulations in dry forests. While the disturbance is a natural process and has ecological benefits, limiting the incidence of beetle outbreaks will limit timber losses and maintain forest health. With that in mind, Vaagen Fibre Canada’s (Vaagen) Peter Flett, RPF, has been undertaking a Beetle Trap Project with the West Boundary Community Forest since 2019 and facilitates a program with the Osoyoos Indian Band in the South Okanagan.
Through the project, Flett has been trapping and tracking beetle prevalence in the southern Boundary area, as well as the West Boundary Community Forest, in a bid to keep his finger on the pulse of the forest health.
“What's great about these traps is that putting them up is a simple method to reduce the population of beetles. In the grand scheme of things, the number of beetles you would trap in a year is a very small percentage of the population, so you're making a small dent in the numbers, but it's helpful for tracking the movement of beetles over time, especially in particularly susceptible areas,” said Flett.
The types of traps used for the project are Douglas-fir beetle traps, also referred to as ‘funnel traps’, where the beetles are drawn to the trap by pheromones and are collected at the bottom of the traps after travelling downward through a series of plastic funnels.
“We tend to the traps every one to two weeks, depending on the time of year. We can compare data year-over-year to observe trends and determine if any increased action is required in a particular area,” Flett explained.
In 2021, the Boundary beetle traps put in place by Flett trapped around 40,000 beetles, while in 2020, the traps captured approximately 20,000 beetles. The highest number of beetles trapped so far was in 2019, at 84,000 beetles.
“What we are finding in the West Boundary are beetle attack pockets all over the place, but normally targeted toward trees on rocky, steep ground or in areas that may be stressed by other factors – it could be drought, fire, or a really hot summer. Under these conditions, the trees are spending much of their energy transporting moisture up the tree to survive. This hinders the ability to fend off insects and disease and makes them more susceptible to being overwhelmed and killed,” said Flett.
Post-wildfire, it is common to observe increased beetle incidence as damaged bark is easier to penetrate and live trees’ protection systems are weakened. Populations will greatly increase as dead trees are targeted and this can create a spill-over effect to remaining live trees.
According to Flett, the beetle traps are beneficial to use in conjunction with other insect management techniques such as salvage harvesting, trap trees, and a repellent program.
“Anti-aggregate bubbles filled with a liquid repellant are fixed to trees for protecting individual trees and small areas. Combining an anti-aggregate program with funnel trapping and salvage harvesting is most efficient in trying to controlling population and reducing tree mortality,” said Flett, adding that the intention isn’t to eliminate the beetles from the forest, as they are part of natural processes and have an important role to play within ecosystems.
The Beetle Trap project undertaken in the Community Forest is managed through Vaagen, while larger scale projects are implemented at the District level through a contract tendering process. The Osoyoos Indian Band manages a trapping and repellent program near Oliver with support from Vaagen.
“The funnel trap program isn’t an alluring topic or an activity that provides wood to local mills; it's just something we think is important to do. In terms of total insect population, it is a drop in the bucket, but with enough drops, you will eventually have a pail of water – or in this case, a pail of beetles,” Flett said. “The work requires time and resources to monitor and implement strategies within our already busy schedules, but the effort to minimize damage to our forests and manage for forest health is important."
Healthy Forests. Healthy Communities