Why you're seeing more tree caterpillars in some parts of Winnipeg this summer
WINNIPEG -- The City of Winnipeg has a five-week window to spray for tree pest caterpillars, like cankerworms and elm spanworms, and this year another familiar foe got in the way — wind.
The program prioritizes areas based on surveillance, where a team looks for the caterpillars and damage to the tree canopy. Ken Nawolsky, the superintendent of insect control for the City of Winnipeg, told CTV News that the crew does the best it can, but it’s not a perfect science.
“We hope that the weather cooperates during that period,” said. “Anytime we get a delay because of high winds or rainfall, we cannot conduct the program that evening, so that does back up what we intended to do.”
Nawolsky said on average, the annual program does 20 neighbourhoods in the city, but this year about 16 will get done.
“Almost every day we’ve had high winds, even going into the night, so that has caused us some operational problems,” he said.
Nawolsky said crews will be out spraying overnight Wednesday and Thursday, but that is it for 2020.
“We definitely always try and go up until the last possible moment,” he explained. “We did the best that we could, and we’re looking for ways down in the future to improve our program so that we’re not as affected.”
Even if you’re area doesn’t get sprayed, Nawolsky said it won’t be long before the hanging worms are gone anyways.
“We’re expecting in the next three to four days that these caterpillars will have finished climbing down from the tree, and that’s it, that’ll be the end of this phase of their life cycle as they prepare to become a moth about two weeks later,” he said.
He also said for next year, if trees get banded by mid-September, it will help with pest control because cankerworm female moths do not have wings and need to crawl up the tree.
“If neighbourhoods do some banding, then that allows us to then not have to go to those neighbourhoods and then go to the one where the elm spanworm is,” Nawolsky said.
Ross Teague has lived in South St. Vital for 20 years, and he said he has never seen anything like this year’s elm spanworm infestation, which has intensified over the last couple of days.
One of the large elm trees in his yard has very few leaves left, and a smaller tree in his neighbour’s yard is totally bare, except for the worms dangling from the branches by their silken threads.
Teague said he has been spraying off his car daily and is picking worms and webs off of himself every time he steps outside.
He has also been cleaning up the worm’s droppings, which look like little black dots, which collect on his driveway.
“I have to shovel off my driveway, I have to hose off the driveway, I have to hose off the recycling bins, I have to sweep off the house, they’re all over my back door,” said Teague. “It’s gross.”
Teague went online to see why his area was not sprayed for tree pest caterpillars, and found that crews stopped spraying for them only a few blocks away from his home.
“It’s frustrating because if you’re going to spray, spray everything that needs to be sprayed,” he said. “Don’t spray one area and leave the other area alone and then spray another area.”
He also called 311, and said he was told insect control is not planning to do any further areas, because by now the insects are getting close to being done feeding.
“Clearly, at least in this neighbourhood, they’re feeding a lot, and there’s less and less leaves every day, more and more poop,” Teague said.
Teague said he would like the city to come to spray his area before it’s too late, but if it’s not done, he is considering spraying the trees himself.