LDD Moths in the Town of Caledon

Gypsy Moth

Here are a few things that you need to keep in mind about LDD moths (formerly known as Gypsy Moths).

Tree health and species are important factors. Generally healthy trees can survive LDD moths. Defoliation from the larva feeding on leaves stops early summer and the moths are short lived. Infestations seem to occur in cycles so while there may be an infestation one year, it does not mean it will continue year after year.

On Town property

If LDD moth are seen on Town property, please contact Service Caledon - 905.584.2272 x. 7750 or info@caledon.ca. It will be investigated by the Town arborist.

Staff will survey the area for egg masses and decide what to do based on the severity of the infestation, level of defoliation, tree health, tree species and available resources.  

Town of Caledon and provincial by-laws discourage pesticide use and staff would not engage in mass application of pesticides without Council direction and approved resources. The Town does not provide any resources for private property.

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 info@invadingspecies.com (on public or private property).  

Frequently asked questions

What is the LDD moth?
The LDD moth is considered to be a major pest in North America. In the caterpillar or larval stage, the insect eats the leaves of trees making them more susceptible to disease and damage from other insects.
How much damage can the LDD moth cause to trees?
Depending on the level of infestation, damage can range from light to almost complete defoliation or loss of leaves. In some situations, if the tree has been weakened or stressed by other conditions, the tree may die.
What kinds of trees are most affected by the LDD moth caterpillar?
LDD moths prefer oak trees but will eat all kinds of hardwoods including elm, birch, poplar and willow trees. In some rare cases, when the number of LDD moth is extremely high, the caterpillar will feed on evergreens such as pine and spruce. They do not appear to like sycamore, butternut, black walnut, dogwood or balsam fir.
What is the lifecycle of the LDD moth?
The moths are short-lived and seen in mid-summer. Both genders die after the female lays its eggs on the limbs and trunks of trees, on rocks, buildings or in other sheltered areas. The egg masses remain in place all winter and hatch the following spring from late April to mid-May. Once hatched, the caterpillars begin to feed for approximately seven weeks.
Are there any natural predators to the LDD moth?
Yes. Predators include other insects like wasps, flies, beetles, ants and spiders and animals such as chipmunks, squirrels and raccoons. When caterpillars first hatch, birds such as chickadees, blue jays, robins and nuthatches will prey on them. LDD Moth populations are also reduced by diseases caused by bacteria, fungi and viruses.
How and when do I protect trees on my property?

May to July

Scrape off caterpillars into water/soap mixture, leave for a few days and then dispose in the garbage. Do not scrape caterpillars onto the ground.

NOTE: Wear gloves since caterpillar hairs can cause skin irritation or allergies.

June to August 

Place burlap bands around trunk where caterpillars will hide during the heat of the day. Check bands regularly and scrape caterpillars into a container with soapy water for a few days and dispose of in garbage.

NOTE: Wear gloves since caterpillar hairs can cause skin irritation or allergies.

July to August 

Pheromone traps are intended to attract and trap male adult LDD moths, to prevent them from mating with females. Generally, this is used as a monitoring technique but may reduce egg mass loading in small areas. Traps should be disposed of in the garbage.

Pheromone traps are available for purchase at home improvement and nature supply stores.

August to early May

Scrape off egg masses into soapy water, leave for a few days and dispose of in the garbage. Do not scrape egg masses onto the ground, this does not kill the eggs and may actually improve survival.

NOTE: Wear gloves since caterpillar hairs can cause skin irritation or allergies.

What is burlapping and how does that help protect trees?

In the heat of the day caterpillars will seek shelter. By placing a burlap band around a tree, you will provide a place for caterpillars to hide and you will also be able to reach the caterpillars and pupae (commonly referred to as a cocoon). Check under the burlap skirt every day and pick off the caterpillars with gloves. Place them into a container of soapy water and leave the container for a day or two, dispose of water accordingly.

Install the burlap in late May (or weather depending, when you see caterpillars start to crawl around on the tree?) and leave till mid-August.

You can purchase burlap skirt from your local hardware store. Follow these steps to burlap trees:

  1. Place burlap around the tree
  2. Tie a rope in the middle of the tree
  3. Fold the burlap over the string
  4. Check under the burlap every day and dispose of caterpillars
How do I build a pheromone trap at home?

The trap uses powerful pheromones to attract and trap male LDD moths, disrupting the LDD moth’s reproductive cycle. The trap acts as a decoy preventing male moths from mating with female moths. While the traps may not catch every moth, they will help to reduce the overall population. Traps should be installed at the end of July when moths start emerging from their pupae. The traps should be removed in early September.

Pheromone 'lure' traps can be found online. Here's how to set up your trap:

  1. Open lure package and pin the lure to the inside of the jar lid. We recommend wearing gloves. If the pheromones in the lure get on your hands, moths will follow you everywhere.
  2. Fill the trap an 1/8th full with water and add a couple of drops of dishwashing liquid. Change the water and soap periodically during the season. The dishwashing liquid helps destroy the LDD moths.
  3. Insert the hanger and screw the lid onto the trap.
  4. Hang the trap securely. Avoid areas where people will be bothered by the moths.

Here are additional resources to help you build a trap at home:

How do I remove LDD moth eggs?

How and where to look

Inspect your property for egg masses between mid-August and the end of April. It is easiest to see when leaves are off. Doing two searches, one in the fall and one again in the early spring will ensure that all egg masses that are reachable will be found and destroyed.

Start in one corner of your property and walk in a systematic manner making sure to look high and low, on all types of vegetation and structures. LDD moths lay their eggs just about anywhere. However, they prefer sheltered locations such as the underside of patio furniture, the underside of branches, on fire wood, rocks and fences. Inspect all surfaces of your house including windowsill, under eaves, around bird houses or mail boxes. Egg masses can be found high or low.

Gypsy Moth Egg Masses

How to destroy the egg masses

First spray the mass with water to stop the egg mass from crumbling. Do not scrape the egg mass onto the ground as it will still hatch. Instead, scrape the mass with a stick or any object with a flat surface such as a knife or paint scrapper into a container such as a brown paper bag and then into a bucket of soapy water. Soak the mass for a few days to destroy the eggs. Dispose of the water in an appropriate manner.

Gypsy Moth Egg Masses   

Gypsy Moth Egg Masses

This resource on Canada.ca shares additional important information.

Additional resources and information can be found on the Toronto and Region Conservation Authority website.