City crews were out in South Osborne this past week, spraying trees for a beetle that spreads Dutch elm disease.
The insecticide Pyrate 480 EC (chlorpyrifos) is sprayed directly onto the lower 50 centimetres of each American elm tree trunk, according to David Wade with the City of Winnipeg’s insect control branch.
"There are two or three species of beetle which burrow into the bark at the base of the tree to overwinter," Wade said. "The beetles carry a fungus that causes Dutch elm disease."
The Dutch elm disease fungus was introduced into North America in the early 1900s via infected elm wood transported from overseas, and which was first identified in Manitoba in the mid-1970s.
The beetle larvae burrow under the bark and create "feeding galleries" where they also transmit the ophiostoma novo-ulmi fungus to the tree. The first sign of Dutch elm disease shows up mid-summer, according to Wade, when leaves on the affected trees turn yellow.

SOU'WESTER
Insecticide is applied to the base of an elm tree in Riverview to kill the elm bark beetles.
Weather permitting, the insect control branch crews will treat approximately 10,000 trees. They can’t treat the trees if it’s too windy or raining.
"In combination with the city forestry crews removing elms which have the disease, and our spraying, we are slowing the mortality rate of the elms," Wade said, adding that homeowners can help keep their trees healthy by watering and fertilizing.
It also helps to spray the elms with a biological insecticide in the spring, when the caterpillars stress the elms by eating the leaves, he said.
Pyrate 480 EC has been approved for use in Canada by Health Canada’s Pest Management Regulatory Agency and will be used in accordance with federally approved label directions by licensed pesticide applicators.
Weekly public service announcements will be issued by the city on Fridays throughout the program indicating which insect management areas will be treated the following week.
Treatment will occur between the hours of 5:30 a.m. and 6:30 p.m. Monday to Friday, weather permitting.
For more information, contact 311 or visit the city’s insect control website at https://winnipeg.ca/PublicWorks/insectControl/default.stm

Susie Strachan
The Sou'wester community journalist
Susie Strachan is the community journalist for The Sou'wester. Susie got her first paying job as a journalist in the late '80s on the Free Press Weeklies, then followed that with 20 years as a reporter, photographer and specialty editor at the Winnipeg Free Press. She then spent 10 years working for WAVE magazine with the Winnipeg Regional Health Authority, before returning to her roots as the reporter/photographer for The Sou’wester. A little bit about Susie: She learns a lot from the people she interviews; She believes that community weeklies provide an invaluable record of community events, places and people; Thanks to all the interviews she's done, she's never met a hobby she won’t try, at least once. She's been thrown out of an airplane while strapped to an instructor, learned to skijor and do it moderately well, and tangled with all sorts of fibre arts. Do not get her started on tie-dyed fingers, lopsided clay pots, the explosion in the basement while brewing ginger beer and other epic failures. Call her at 204-697-7150 or email her at: susie.strachan@canstarnews.com