Sponge Moth/LDD (formerly known as Gypsy Moth)

Important information regarding the Sponge Moth/LDD (formerly known as Gypsy Moth) moth infestation and what you can do as a property owner and member of our community.

Important Resources:

A Message from the TBA on Sponge Moth/LDD (formerly known as Gypsy Moth) Moths: 

February 2022 Update

An LDD Moth Update was included in the TBA newsletter emailed on December 16, 2021.

Although an LDD spray program is not planned in the TB community this spring, any property owner concerned with their own individual property (i.e. high egg mass counts) can apply for spraying directly to the Ontario Centre for Forest Defoliator Control (which is a spin off from Zimmer Air) at www.ocfdc.com.  Please note the OCDFC’s March 1st cut-off date is subject to change due to volume and demand.   It is recommended to note Thunder Beach on your application to help identify the area.  Applicants are responsible for obtaining required waivers from any non-spraying abutting property owners.

Property owners who participated in Zimmer’s LDD/Gypsy Moth aerial spray program last year should have received an email from Chelsea Vollrath at the OCFDC on January 14 , 2022 outlining the 2022 application procedure. 

A link to the February 7th Midland Today article re: Tiny Township’s recent special Council meeting with the SSEA, Simcoe County and MNR follows:


Highlights include:

1)  Tiny Township will not fund an aerial spray program and it will be up to individual property owners to organize and pay for any spraying;

2)  Positive signs across the province indicate that the entire outbreak is starting to show signs of decline due to presence of NPV Virus, parasites and fungus E. maimaga; and 

3)  An LDD population decline was anticipated for 2022.

The 2021 aerial spray program was successful in our community and it was expected that it would significantly help to reduce the LDD Moth population in 2022.  Other control measures like tree banding, tree injections and the use of LDD/Gypsy Moth traps continue to be encouraged each year.  Hoping a natural virus and the extreme cold temperatures in cottage country this winter and/or a wet spring also help!

December 2021 Update

The 2021 LDD Moth Aerial Spray Program was successful in the Thunder Beach community with trees saved and less caterpillars and egg masses produced. Thank you to everyone who also participated in the Township’s survey earlier this fall, however, it doesn’t appear that Tiny will coordinate a municipal spray program for property owners in the Township.

Evidence has not been received to suggest that further spraying will be necessary in the Thunder Beach community next spring.  

Any property owner concerned with their own individual property (ie high egg mass counts) and wishing to apply for spraying should contact the Ontario Centre for Forest Defoliator Control (a spin off from Zimmer Air) directly at www.ocfdc.com . Interested property owners must apply individually and someone from the Centre will contact you to obtain payment and mapping details. It is recommended to note Thunder Beach on your application to help identify the area.  Applicants are responsible for obtaining required waivers from any non-spraying abutting property owners. The OCFDC’s application deadline is currently March 1st, 2022 but may close earlier in the new year due to demand throughout the province.

The MNR plans to issue their 2022 LLD infestation projection map early in the new year and post it online at https://www.ontario.ca/page/gypsy-moth.


Spring 2021 Update

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 thunderbeach.org 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.