The Town of Oakville is taking action to control gypsy moth infestation

Tue, 27 Apr 2021

Aerial spray program in town woodlands, May 2021

This spring, the town will be conducting an aerial spray in select town woodlands with a safe and naturally occurring pesticide to control gypsy moth infestation. Please visit our Gypsy Moth page for more information and a map of spray locations.

Based on population surveys conducted in 2020, Oakville faces extreme levels of gypsy moth infestation in 2021 that could affect 102 hectares (252 acres) of town woodlands, resulting in a significant loss of trees if no action is taken.

When?

• Aerial spraying will occur between May 1 and June 15, 2021, most likely in mid-May once the gypsy moth caterpillars have emerged. Spraying will take place early in the morning, between 5 and 8 a.m.
• Two treatments will be necessary within a few days of each other.
• Aerial spray dates are highly dependent on weather conditions. Once dates are confirmed, we will post them on our Gypsy Moth page and on our Facebook and Twitter feeds.
• Additional ground spraying may occur during the same period to target town trees adjacent to woodlands that have been identified as high-risk for gypsy moth presence.

How?

• Spraying will be performed by a low flying helicopter over the designated woodlands.
• The treatment being used is Bacillus thuringiensis subspecies kurstaki (Btk), registered under the trade name of Foray 48b Biological Insecticide Aqueous Suspension. Btk is approved for use by Health Canada and has been identified as the most effective method to control gypsy moth infestation in woodland areas. 

Where?

• There are 16 woodlands in the gypsy moth aerial spray program. Visit our Gypsy Moth page to review the affected woodland in your area.
• The designated woodlands and trails will be closed temporarily during the spray and reopen immediately after. Closure signs will be posted. Some roads may be closed briefly as the helicopter passes.
• Aerial spraying will not take place over town streets or residential properties.

What should I do?

• No special precautions are required for residents near the spray areas. You may wish to alter your early morning plans such as running or dog walking on spray days or if you prefer, remain indoors and close windows during the spraying, but this is not necessary.
• There are no health concerns with entering the woodlands after trees have been sprayed.

About gypsy moth

Gypsy moth is a non-native insect that is considered a major destructive pest in North America. These insects can be a concern because the larvae (or caterpillar stage) feed voraciously, mostly on the leaves of leafy trees such as oak. If the population is high, they can eat all the leaves on a tree in a short amount of time. While trees can often survive one season of losing leaves, successive years where leaves are lost can cause trees to die and become unsafe.

About Bacillus thuringiensis Kurstaki (Btk)

The aerial spray will use Foray 48B Biological Insecticide Aqueous Suspension, containing active ingredient Bacillus thuringiensis, subsp. kurstaki (Btk) strain ABTS-351, (PCP# 24977) under the Pest Control Products Act (Canada).

Research shows that Btk used in aerial spray programs has no negative environmental or human health effects. Btk is a bacteria which occurs naturally in soil. The bacteria is poisonous only to a certain group of insects when ingested during their larvae stage. Btk does not affect adult moths or butterflies or other beneficial insects such as honeybees, pets, birds, fish, or mammals.

If you have questions or concerns related to the health impacts of aerial spraying with Btk, please call the Region of Halton Public Health Department at 905-825-6000.

More information

Public safety and the health of our environment are top priorities at the Town of Oakville. We understand there might be some inconvenience on the mornings the aerial spray takes place and we appreciate your patience and cooperation. You can find more information on our Gypsy Moth page.

For any further questions please contact ServiceOakville at 905-845-6601 or toll-free at 1-877-625-8455 or service@oakville.ca.