Barrie councillor wants staff to explore options to wage war on gypsy moth caterpillars next year

One of the worst outbreaks in years in parts of Ontario

They are all over the place.

Crawling on trees, chewing on leaves, and people out for hikes say you can hear the crunching as gypsy moth caterpillars feast in wooded lots.

At Monday’s general committee meeting, Barrie city councillor Robert Thomson’s item for discussion asks staff in the operations department to investigate the feasibility of aerial spraying or the use of pheromone traps for the prevention of gypsy moths, including the costs, and to report back as part of the 2022 Business Plan and Budget process.

His focus on next year suggests the ship has already sailed in terms of a current plan of action.

On its website, the Nottawasaga Valley Conservation Authority (NVCA) says the Ministry of Natural Resources and Forestry (MNRF) and Simcoe County‘s prediction that 2021 was going to be an outbreak year for gypsy moths have already been proven to be correct.

Gypsy moth caterpillars are the pest of spring-summer 2021 in the region

Rick Grillmayer, NVCA’s Manager of Forestry, says gypsy moths are seeing a peak in population this year and likely for the next couple of years, until there is a natural crash in their population.

“I have seen caterpillars travelling across large fields in search of suitable foraging areas,” Grillmayer is quoted as saying on the NVCA website.

The NVCA says gypsy moth populations are cyclical, peaking after 7-10 years then crashing from parasites or fungus. High concentrations of the caterpillars will defoliate trees. The conservation authority says a healthy tree will likely survive, though young, newly planted trees that were already stressed may not bounce back as easily from the defoliation.

Graeme Davis, forester for the County of Simcoe, told Barrie 360 the last time the region saw an infestation to marvel this one was around 1990-92.

“It’s not just within the county, by the way. There are certainly reports of pretty widespread impacts across South and Central Ontario this year. But we were anticipating that there would be a fairly severe hatch this spring. And that’s definitely what we’re seeing,” he said.

Davis suggests property owners use gloves to pick the insects off one-by-one or spray a soapy solution onto affected trees. He says wrapping burlap or other fabric around the trunk of the affected tree can help collect the insects for removal.

“What that does is provide a space for the caterpillars. They’ll tend to climb down and look for a shady spot during the heat of the day. They’ll climb down the base of the tree and underneath that flap of cloth or burlap. And using some gloves, you can scrape those off and drop them into some soapy water to control numbers that way.”

petition was created to have the City of Barrie perform an aerial spray to control the gypsy moth population. Unfortunately, the petition was started too late.

“Staff did look into the option of aerial spraying; however, it takes months of public consultation, public notices, environmental approvals and flight approvals along with the tendering process to get a company in place,” said Kevin Rankin, the city’s Supervisor of Urban Forestry. “For BTK applications (aerial pesticide) to be effective, precise timing is essential. BTK must be applied after larvae hatch and begin feeding but before larval development beyond the second instar stage, as in this week, no later.”

Rankin points out the cost of aerial spraying would outweigh the short-term benefits.