LDD / Spongy Moth / Gypsy Moth FAQ
Lymantria dispar dispar (LDD), previously known as the Gypsy Moth, is an invasive species that has been in Canada for over a century. If you think your tree may be infested by LDD / Gypsy Moth or larvae, contact P & A for a diagnosis, assessment, and advice.
Q: What is Lymantria dispar dispar (Spongy Moth)?
A: It is an insect that was imported in the early part of the 1900s from Europe and first appeared in the United States. It moved into Ontario in the early 1980s.
Q: How does LDD / Spongy Moth affect the tree?
A: Larvae hatches in early spring and starts to feed on tender leaves, eventually stripping the tree of its leaves.
Q: Which trees are affected by LDD / Spongy Moth?
A: Primarily Oak trees, but may affect other trees when populations of the insect are high.
Q: What will happen to an infested tree?
A: If the leaves are eaten by the larvae for two consecutive years, the tree may die.
Q: What signs should I look for in my trees?
A: Egg masses (400 to 700 eggs) are easiest to identify as they are tan in colour and suede-like in appearance. They are about 2.5cm in diameter on the trunk or limbs of the Oak. They are easiest to identify in the late fall or winter.
Q: What is the prevention or treatment?
A: Scraping egg masses in the winter and early spring is effective. Placing sticky bands on the trunk or folding burlap around the trunk. Past practice for some property owners has been ground or aerial spraying of a naturally occurring entity, called Btk, Bacillus thuringiensis subsp. kurstaki.
Q: Where is LDD / Spongy Moth active?
A: Across Ontario.
Q: Where can I get more resources about LDD / Spongy Moth?
A: View the Ontario government’s information sheet about LDD / spongy moth and stay up to date on provincial information on the government website.
If you are a woodlot owner, click here to get help developing a survey program to determine if you need to implement a control program or seek outside help.
If you believe your trees could be infested with LDD / spongy moth or if you have any inquiries, please contact us! Note, we do not perform LDD spongy moth spraying or treatment ourselves. As a certified arborist, we can make recommendations for managing LDD on your property, providing risk assessments for dying trees, and other professional advice and reporting.