City of Barrie checking options in war on gypsy moth caterpillars

Staff to investigate feasibility of aerial spraying

Thousands of gypsy moth caterpillars are on a feeding frenzy in Barrie and across a good chunk of southern and eastern Ontario, chewing their way through foliage like there is no tomorrow.

Based on the number of calls some city councillors are getting about the wiggly critters, many residents don’t see a tomorrow for their trees if action isn’t taken as soon as possible.

Gypsy moth caterpillars crawling up a tree in Barrie

Councillor Robert Thomson’s item for discussion was approved at general committee on Monday that staff investigate the feasibility of aerial spraying or the use of pheromone traps for the prevention of gypsy moths including the costs and report back as part of the 2022 business plan and budget process.

An amendment to include border wooded lot regions was added to Thomson’s item for discussion by Councillor Ann-Marie Kungl and approved.

Kungl said in her Ward three, in particular Nicholas Drive that borders on Springwater Township, it is “raining caterpillars.”

Staff said there would need to be consultation with border communities anyway because of the use of a pesticide.

Andrea Miller, the city’s general manager of infrastructure and growth management, said staff is proposing two different approaches for councillors to consider.

“One, which is what staff have always understood was the intention, is that it would be on city woodlots that we would be addressing and not broad residential areas,” said Miller. “If it’s council’s intention that you do want to go into residential areas, that is going to obviously be a very different approach and much more consultation, and obviously much more cost.”

“It’s really going to depend on the direction that council gives staff. But consultation with our neighbours and the broader community will definitely need to be part of the process.”

Kungl said for some residents where there is greenspace that borders Springwater Township, residents are heavily engaged in preventative practices to combat gypsy moth caterpillars and it really hasn’t made a difference.

“It’s quite literally creating inhabitable yards for residents,” she said.

Thomson is of the belief the gypsy moths are also a health issue.

“I think that people are having an allergic reaction to these caterpillars,” he said. “If you go out and talk to some of these residents they look like they have been rolling around in poison ivy.”

Staff said residents can continue to call in about boulevard trees that have been impacted by gypsy moths. Councillors were told there isn’t the staff available to go out and address all of the trees. The city is working with a consultant to try and identify hot spots within Barrie so staff know where to do treatment in the future.

For now, the recommendation is for residents to wrap their trees in burlap. When the caterpillars are going down the trunks they will get trapped and that’s when people should use soapy water to finish them off.

Thomson said he wants staff to do some investigating so the response isn’t knee jerk.

He was amazed by what he saw during a visit to Sunnidale Park, which is in the heart of the city.

“It looks like a fire has gone through and taken all the leaves off.”

Staff said they have been treating some of the larger oak trees in Sunnidale Park with a chemical, but that it is a very manual process and takes a long time. Councillors were told staff was doing everything the province has recommended to fight gypsy moths other than aerial spraying.

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.

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.

Last year alone, the Ontario Ministry of Natural Resources says around 570,000 hectares of tree defoliation took place in the province because of gypsy moths.

City council must rubberstamp the approved item for discussion at its meeting on June 28.