Spongy Moths

The Lymantria dispar dispar (LDD) is a major forest pest concern because the caterpillar, or larva stage of the insect, eats the leaves of trees, defoliating them which makes them more susceptible to disease and damage from other insects, like tent caterpillars. Continued defoliation of trees can lead to their decline and eventual death. While this pest can consume the leaves of most trees, it tends to feed mostly on Oak, Cherry, Birch, Beech, Spruce, and Pine.

View the LDD Moth Brochure (PDF)

For more information, visit Health Canada's Spongy Moth webpage

How to manage a Spongy Moth infestation on your property

May to July: Hand Pick Caterpillars

Handpicking caterpillars is most effective on small newly planted trees, shrubs and plants infested with LDD moth. If possible, gently shake the tree so caterpillars fall from the leaves. Thoroughly inspect the remaining foliage, branches, and trunk for caterpillars and using gloves, pick them off your tree. Fallen and collected caterpillars should be placed and left to soak in soapy water to destroy them.

June to August (larger caterpillar stage): burlap banding

Once caterpillars grow to about an inch (2.5 cm) in length by mid-June, they will move down the trunk to seek shelter from predators and heat during the day. Reduce the number of larvae on the trees in your yard by trapping them.

Required Supplies:

Burlap cloth
Twine or rope
Bucket of soapy water (dish soap works well)

Step-by-Step Instructions:

Wrap and secure a piece of burlap cloth around the stem/ trunk of your tree
Tie twine or rope around the center or slightly below the center of the burlap
Drape the burlap cloth over the twine or rope so there is an overhang where the caterpillars can crawl underneath to seek shelter during the day
Check the trap by lifting the overhanging cloth every afternoon and collect any hiding caterpillars
Put them into a bucket of soapy water for a few days to destroy them

July to August (female moth stage): burlap wrapping

Trap female moths, wrap burlap lower on the trunk of the tree to trap the female moth (which are unable to fly) before it crawls up the tree and lays eggs. This is the same method used for the larger caterpillar stage. Once captured, drown the moths in soapy water.

August to May: egg mass removal

rap female moths, wrap burlap lower on the trunk of the tree to trap the female moth (which are unable to fly) before it crawls up the tree and lays eggs. This is the same method used for the larger caterpillar stage. Once captured, drown the moths in soapy water.

August to May: Egg Mass Removal

Survey your property for egg masses and scrape them off surfaces into soapy water to destroy them.

Required Supplies:

A flat object such as a butter knife or plastic paint scraper
Catchment container or bag to collect the egg masses
Bucket of soapy water (dish soap works well)

Step-by-Step Instructions:

Place your catchment container below the egg mass
Use your scraper tool to remove the egg mass from the surface. Ensure that all eggs are scraped. Try not to leave any residual eggs in bark ridges or crevices
Empty the contents of your catchment container of bag into a bucket of soapy water
Leave eggs sitting in the bucket for a day or two, then dispose of the contents

Egg masses can be located high up in trees. Care needs to be taken if trying to access anything up high, especially if using ladders. Some private tree care companies can be hired to provide this service at heights.