UPDATE: March 26, 2020

The 2020 aerial spray program for gypsy moth will be underway in the coming months. Council approved the public works report on March 23, 2020, which identified the spray blocks proposed to receive the aerial spray program.

The total number of hectares to be sprayed through the 2020 Town of Pelham Gypsy Moth Aerial Spray Program is limited based on the available budget, and application cost estimates from Zimmer Air Services. The identified spray blocks have been designed to have the greatest impact on preventing defoliation and protecting the health of the most vulnerable trees in accordance to the Gypsy Moth Management Policy and IPM strategy. Due to the level of infestation and program size limitations, the threshold for treatment consideration was raised from 2,500 egg masses per hectare to 5,000 egg masses per hectare for the 2020 spray program. 

In the report to Council, director of public works Jason Marr indicated that this year’s program is twice as large as last years in terms of hectares spayed. 

Originally, two public meetings were scheduled to be held in mid-April, however, with COVID-19 measures in place to decrease the spread of the virus, the Town will work towards alternative community engagement. Once finalized, this will be communicated through the Town’s website, social media channels and in the Voice of Pelham newspaper. 

Finalized spray block mapping will be available in the coming week.

UPDATE: March 4, 2020

At the March 2, 2020, meeting of Council, the recommendation to move forward with a gypsy moth spray program utilizing the $150,000 approved budget was given the green light. This option provides aerial spraying for 33 hectares of municipal property and 90 hectares of private property.

Identifying spray blocks and the locations to receive the application will now commence. Once the spray blocks have been identified, maps identifying the areas receiving the aerial spray program will be made available. To stay up to date with all gypsy moth related information, subscribe to www.pelham.ca/gypsy-moth

In November 2019, Lallemand Inc./Bioforest was selected to develop gypsy moth monitoring plots, conduct egg mass density surveys, and provide a report to the Town of Pelham including: 

  1. An assessment of the gypsy moth infestation
  2. Forecasts of likely defoliation for these areas in 2020
  3. Short- and Long-Term management options
  4. Specific recommendations for management in the affected areas for 2020

Read the full news post

View the policy

View the public works report

View Bioforest presentation to Council


UPDATE: February 19, 2020

Pelham Town Council, sitting as Committee of the Whole, received the public works report outlining the Town's proposed gypsy moth policy and 2020 gypsy moth management options and the establishment of a forestry health reserve fund.

Reports from the consultant hired last year to conduct egg mass survey suggest that 2020 will be another severe infestation year. 

The consultant will be presenting to Council on March 2. 

View the report



UPDATE: January 6, 2020

BioForest, the company contracted to complete gypsy moth egg mass surveys, began surveying today. Surveys are done from public property; private properties will not be entered for surveying purposes.

This page will be updated as new information becomes available.


UPDATE: October, 23, 2019

Please review the six alternatives discussed at the public meeting. You can submit your comments/preferences to gypsymoth@pelham.ca

For the second time in as many days, Pelham Town Council heard from residents on an important issue that, despite only having directly affected certain pockets of town, could have large scale impacts if not dealt with in a timely and sufficient manner.

The gypsy moth infestation that the Town and residents battled in 2019 was mitigated through an aerial spray program that yielded desired results: trees were saved.

However, despite the program’s success, there is an appetite for staff and Council to gain public input on how future year’s programs should be conducted, at what cost, and how that cost will be shared, if at all. 

“We were under a biological deadline and we did not have the $100k [to cover the cost] in 2019,” said Mayor Marvin Junkin. “Yes, there’s some more money now and going forward I hope we don’t’ do this again.” 

Jason Marr, director of public works, gave a presentation on the origins and biology of the gypsy moth as well as the process that unfolded in 2019, outlining the spray program itself, where spray blocks were situated, timelines, costs, and ultimately, six alternatives for consideration moving forward. 

The room also heard how climate change plays a role in invasive species and their intrusion to the municipality. The global spread of harmful forest pest species, like the gypsy moth, is a direct consequence of change, permitting the invasive species opportunity to expand their boundaries. The risk of damage caused by the Gypsy Moth to Canada’s deciduous forests is estimated to grow from the current 15 per cent to more than 75 per cent by 2050.

Alternative 1 Alternative 2 Alternative 3 Alternative 4 Alternative 5 Alternative 6
alternative one 1 with leaf alternative one 2 with leaf alternative one 3 with leaf alternative one 4 with leaf alternative one 5 with leaf alternative one 6 with leaf

Click the image to enlarge the alternatives

“Most likely we will have some type of spray program next year,” said Marr, alluding to the fact that the infestation survey has not been undertaken to date. “We did receive approval from Council to retain a forestry consultant to complete an infestation survey.”

Without the study, early, rough estimates indicate that a similar spray program to 2019 would be in the ballpark of $100,000.

When residents shared their stories, comments, and feelings on all things gypsy moth, many ideas spanning from using volunteers to creating a committee to using home prevention methods came to the forefront. However, Council and staff would like as much feedback as possible in determining what program will be most effective in mitigating the gypsy moth infestation and is amenable to residents. Though all comments were recorded by staff, there is further opportunity for residents to submit feedback on the gypsy moth spray program in general as well as ideas and endorsements for how to proceed moving forward. To do this, residents can email gypsymoth@pelham.ca.

Paul Robertson of Trees Unlimited was on hand to answer questions from Council and residents, responding to inquiries on costs, mapping, surveying and more. 

For more information on the gypsy moth aerial spray program in 2019 and more, visit: www.pelham.ca/gypsy-moth

UPDATE: (August 6, 2019):

Please see below the revised mapping reflecting the areas that were sprayed during the Gypsy Moth Aerial Spray Program: 


UPDATE (June 10, 2019):

The gypsy moth spray program for 2019 is now COMPLETE.

UPDATE (June 5, 2019):

Gypsy moth spraying will NOT occur today, Wednesday, June 5, due to the weather forecast. The second application for urban areas will occur later this week.

UPDATE (June 3, 2019):

The second application of the gypsy moth aerial spray program is tentatively scheduled for Wednesday, June 5 - weather pending. The anticipation is that the aircraft will spray the areas in identified spray blocks earlier than the first application (9:30 a.m.) though a precise time is not known. Please visit: www.pelham.ca/gypsy-moth for up-to-date information. Updates to the time and date change (if required) will be posted there first.

UPDATE (May 31, 2019):

The first application of the aerial spray program was administered this morning, treating all areas in the identified spray blocks. The second application will take place sometime next week. Check back for updates as they become available or keep an eye on the Town's social media channels to stay up to date.

UPDATE (May 30, 2019):

Spraying is scheduled to occur later in the morning on Friday, May 31, roughly around 9:30 a.m.

UPDATE (May 23, 2019):

Have some questions about safety precautions prior/during/after the aerial spray program for gypsy moth? Please review some of the frequently asked questions below.

What personal precautions can be taken in preparation for aerial spraying? 

Members of the public are unlikely to experience any health effects, and no special precautions are necessary or required. Individuals who have concerns should take reasonable precautions to avoid exposure during an application period of the program.

While no special precautions need to be taken, the following measures may be considered by residents living in treatment areas:

  • Whenever possible, remain indoors for 30 minutes after spraying to allow for the droplets to deposit onto the tree leaves.
  • Bringing laundry, toys and pets indoors before spraying begins.
  • Practice good personal and food hygiene (e.g., hand washing after outdoor activities, especially after gardening; leaving outdoor shoes at the door; washing all fruits and vegetables before eating or cooking).
  • Covering lawn furniture, outdoor tables, pools, BBQs, play equipment and sandboxes and/or rinsing them off with water after spraying is finished.
  • Minimize opening and closing windows and doors during the spraying.
  • Shutting off the heating/cooling vents or selecting the recirculate setting.
  • Contacting your family physician if you are concerned that a personal medical condition may be aggravated by the spraying.

Does Btk spraying pose a risk to residents who might have sensitivities? 

Members of the public are unlikely to experience any symptoms and no special precautions are necessary or required. However, infrequently there may be some residents who are more sensitive and may experience skin, eye or respiratory irritation. Btk aerial spraying is not expected to have adverse effects on vulnerable populations including children with asthma, people with weakened immune systems, pregnant women or the elderly.

What should I do if I experience an adverse reaction? 

If you experience an adverse reaction or worsening medical condition, speak to your physician or, in an emergency, call 9-1-1.

Can gypsy moth affect my health directly? 

Extreme gypsy moth outbreaks have been associated with skin rashes and upper respiratory tract irritation in some people exposed to airborne gypsy moth hairs, silken threads, or shed skins. There is a potential for some people to develop minor skin irritations or rashes when they come in contact with these insects. If this is a concern, it is recommended that you try and avoid contact whenever possible.

How can I receive updates about the aerial spray?

Updates on the aerial spray program will be available on the Town’s website (www.pelham.ca/gypsy-moth).

What is Integrated Pest Management (IPM)? 

IPM focuses on the long-term prevention and mitigation of pests or their damage through techniques such as monitoring, biological control, habitat manipulation, and modification of cultural practices, such as the use of gypsy moth resistant tree varieties

UPDATE (May 22, 2019):The first application of the aerial spray program is Friday, May 31, 2019. The application is expected to occur early in the morning (estimated time around 5:30 a.m.). The program is administered by aircraft, creating a brief but loud audible disruption. The second application is tentatively scheduled for Wednesday, June 5. The application will once again occur early in the morning.

Costs to property owners will be approximately $230, approved by Council at the last meeting on May 21, 2019. Questions, comments, and concerns can be directed to the contacts below. 

UPDATE (May 15, 2019):

The Town received updated spray maps (below) for the properties to be included in the gypsy moth aerial spray program. Additionally, a list of addresses within the spray blocks and just outside the spray blocks is provided for quick reference. Dates for spraying are still to be determined. Updates will be provided as they become available.

Click the photo to enlarge.

North South Defoliation Mapping


UPDATE (April 26, 2019):

The Town of Pelham, in an effort to control the gypsy moth infestations, will conduct an aerial spray program sometime between mid-May to early June. A final date is pending and dependent on weather conditions. As soon as a date is confirmed, this page will be updated.

The spray program will be administered by Trees Unlimited, working with Zimmer Air, covering a total of 118 acres consisting of public and private property.

Final mapping for the affected areas is currently underway and those homes identified in the spray blocks will be notified by direct mail. Properties just outside of the spray blocks will also be notified by mail. There is not an option to opt in or out of the program.

The spray program uses a biological insecticide called Foray 48B Biological Insecticide Aqueous Suspension(Pest Control Products Act #24977), its active ingredient being a naturally occurring soil bacteria called Bacillus thuringiensis v.kurstaki, or Btk, which only affects spring caterpillars feeding in the upper canopy of hardwoods.

Two applications of Btk will be applied to affected areas and is dispersed by a twin engine helicopter, creating a brief, but invasive audible disruption. The application time is approximately 15 minutes with the biological insecticide staying suspended for approximately 5-10 minutes. Btk remains lethal to the caterpillar for approximately four days. Ultra violet light and rain will gradually breakdown the bacteria.

As specific details for the aerial spray program are confirmed, they will be update on this page, so please check back regularly until the program is complete.

For more information, please contact:

Ryan Cook
Manager, Public Works
905-892-2607 x362

Jason Marr
Director, Public Works
905-892-2607 x313

Christine Tonon
Administrative Assistant, Public Works
905-892-2607 x332

Contact Us