The City of Winnipeg will commence its tree pest caterpillar control program starting Sunday to ensure the sprouting foliage stays.

Beginning at 9:30 p.m. weather permitting, the tree pest caterpillar control program in Insect Management Areas 21 (Fort Richmond), 30 (South River Heights), and 38 (Deer Lodge).

Spraying is scheduled to occur Sunday to Thursday evenings during this projected 4-week program. Treatment will only happen when the weather conditions are conducive for spraying.

"The tree pest caterpillars have hatched based on the most current surveillance data and they are actively feeding on leaves," says David Wade, Superintendent of Insect Control. "Winnipeggers can expect to see moderate levels of defoliation in some parts of the city based on our observations."

This season’s program will be treating boulevards, as well as City parks and cemeteries where tree pest caterpillars are high in numbers and where they are starting to defoliate trees. Daily inspections by ground surveillance crews will be used to prioritize the Insect Management Areas to be included in the treatment program.

Treatment will be conducted utilizing Bacillus thuringiensis subspecies kurstaki (Btk), a biological, organic product which is sprayed from high-pressure tree sprayers directly onto the foliage of the trees. Once Btk is ingested by the tree pest caterpillars, they stop feeding and perish approximately two to three days later.

This product 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.

Buffer zones

All buffer zones will be respected. Crews will ensure that the sprayer is not treating within 30 metres on each side of a registered property on the front street, side street, and rear lane.

Residents can apply for a 30-metre buffer zone to exempt their property during the tree pest caterpillar treatment program. Property owners not wanting insecticides applied on or adjacent to their principal residence may register as “Anti-Pesticide Registrants” for tree pest caterpillar control using Btk. Those who want to register must provide identification that ties the registrant to the address being registered for a buffer zone. A photocopy or scanned document such as a driver’s licence or utility bill will suffice as acceptable identification proving primary residence.

Buffer zone applications must be received through one of the following options:

Register for notification

The Insect Control Branch offers an automated telephone and email notification system. Residents who register for this service will receive daily phone or email notifications for all tree pest caterpillar control activities. Residents can register for notification online or by contacting 311. 

More information

For more information, contact 311 or visit the City’s Insect Control website.