Council responds to LDD Moth issue

Tablet with Town logo

UPDATE (June 4, 2021) -- The Town of Caledon recognizes the impact of this year’s LDD moth population and is working diligently to prevent further infestations. To date, the Town has responded to and treated 79 infestation sightings/reports.  Arborist staff investigated those reports and monitored them for rate of canopy defoliation (health of the tree) and egg mass density (indicates severity of the infestation).

Earlier this year, staff performed egg mass scraping at all locations and noticed high densities of egg masses on 60 large oak trees within Town parks in Bolton and Palgrave Estates.  As a result these trees were sprayed from the ground with BTK in 2021. Based on last year’s tree health monitoring program, LDD moth was expected to have lower numbers in 2021 than what Caledon has actually experienced, therefore, no mass spraying was planned.

At this time, spraying infected trees with BTK will not be effective.  Moving forward the goal is to discourage multiple year destruction of Town owned trees to ensure overall tree canopy health. 

Staff are developing an enhanced Integrated Pest Management (IPM) program for the entire municipality.  A recommended action plan will be presented to Council July 7, 2021 for consideration.  The report will include the action plan for the remainder of 2021 and 2022 for a more extensive investigation and monitoring, increased egg mass scraping, tree banding and Btk spraying as well as an education plan.  

Staff are actively consulting with experts from the local conservation authorities, other municipalities and tree care professionals and will continue to monitor LDD infestations on Town owned property through 2021. 


May 26, 2021 – As a result of current LDD moths (formerly known as gypsy moths) levels, Town Council directed staff to explore additional avenues to manage infestations on Town property in partnership with the Toronto and Region Conservation Authority and Credit Valley Conservation Authority.

"I understand the impact that LDD moths have had on our residents, and I share their frustration," said Mayor Allan Thompson. "This is why we're asking staff to investigate other avenues to control the spread of LDD moths, and further educate residents about how to handle the infestation on their property."

Staff have been asked to look into reported problem areas and determine an action plan for the remainder of 2021. Council allocated $100,000 in emergency funds to immediately manage the issue on Town land. Staff will be bringing this plan to Council in July. In addition, staff were directed to develop control strategies and a management plan for Town property in 2022. 

Educational Resources

Join TRCA for an online introduction to LDD moth management. Learn about their life cycle, how to identify them, and what actions you can take to minimize their impact to trees.

Tuesday June 8, 2021 | 6:30 to 7:30 p.m.

Register: LDD Moth Management: Protecting our Forests

Learn more about LDD moth and how to protect trees on your property including tree wrapping and pheromone traps:

LDD moth on town property

If LDD moths are seen on Town property, please contact Service Caledon - 905.584.2272 x. 7750 or for investigation by a Town arborist.

Staff will survey the area to determine what trees in question are on Town property and decide what to do based on the severity of the infestation, level of defoliation, tree health, tree species and available resources. This may include working with external contracted services to identify the best option to manage LDD moths while they’re still in their caterpillar stage.

LDD moths on private property

Property owners need to consult with their chosen tree care professional to determine the best way to manage their own property. The Town does not provide service to private properties.

Community members can also report LDD moth sightings to the Invading Species toll-free hotline at 1-800-563-7711 or email (on public or private property).

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Media contact
Stacey Abbott
Manager, Corporate Communications
647-616-0923 | | @YourCaledon