Gypsy Moths

Important information regarding the gypsy moth infestation and what you can do as a property owner and member of our community.

Please note that the deadline to apply for spraying with Zimmer Air was March 1, 2021 All members of the Thunder Beach community are encouraged to review the information provided below.

Important Resources:

A Message from the TBA on Gypsy Moths: 

Gypsy Moth Aerial Spray Control Program Update - Spring 2021

Spray dates are fast approaching for the gypsy moth aerial spray control program in the Thunder Beach community.  Zimmer Air suggests checking their website map (see link below) for updated info re: spray dates and guidelines.  They also plan to provide dates to both Tiny Township and Simcoe County to post on their respective websites closer to the actual spray dates.

Currently Zimmer’s website map shows approx. May 29-31 for the first spray date in Tiny Township.   The second spray date follows within approx. 10 days.    

Important information to note from the Zimmer Air website:

“Aerial applications will begin when we have 90% hatch and sufficient leaf out has been achieved.  Refer to the Map on the Website for your area.  This a GUIDE and NOT a “must spray date”.  

“Applying the Btk to align with all requirements may provide some anxiety as you are seeing caterpillars, but rest assured we will be able to provide effective gypsy moth larvae control based on our proven science based application methods.”

 Zimmer’s Website also includes a list of FAQ’s at this link:   

Some helpful suggestions re: Btk spraying follow:

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.Bring laundry, toys, cushions 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. 

It is recommended that you cover all surfaces you would prefer not to be exposed to a film of spray or wash with water soon after spraying.  

The spray does not damage automobile, trailer or boat paint or finishes.  It can be washed off with water soon after the spray.  If left to harden it may take more effort to wash off.  

We also have an FAQ list available here that can be accessed at anytime from under resources.   Property owners are encouraged to review this information which includes additional proactive measures recommended to be taken throughout the year to help control the gypsy moth population

Thanks for your support of the gypsy moth spray control program and for your ongoing efforts helping protect the trees in our community. 

Here’s to a successful spray season and safe summer for all!  

Barb Reidl



Winter 2020 Update

This summer saw a horrible infestation of Gypsy Moths which decimated many trees.  According to the Ontario Government, the defoliation caused by gypsy moths in Ontario increased from 47,203 hectares in 2019 to 586,385 hectares in 2020.  In the spring of 2021, the Gypsy Moth caterpillars will emerge from the egg masses in the trees.  Consequently, action must be taken now. 

At last summer’s Annual General Meeting, a motion passed for the association to provide information to all of our members regarding safe proactive measures that can and should be taken.  

Health Canada has approved an organic pesticide, which is naturally occurring in soil bacteria, called Bacillus thuringiensis kurstaki (“Btk”).  It has been used by many communities including the Grand River Conservation Authority.  According to the Grand River Conservation Authority website, it has been used for over 30 years and has very little impact on other insects, birds or mammals.  

Zimmer Air has set up numerous spraying programs of Btk for municipalities, private landowners, and associations. If last summer is any guide to us, the risks of doing nothing are too great.  

Special thanks to Barb Reidl and to the team at FOTTSA for their ongoing work and assistance on this important issue.

*This message originally appeared in the Winter 2021 Newsletter.  We will continue to post any pertinent updates on this page. 

The Thunder Beach Association is providing this for information purposes based on our understanding of the problem and proposed solution.  The decision to conduct spraying is up to each property owner.