The LDD moths (Gypsy moths*) in QTN have started laying eggs. You can help to reduce the number of caterpillars next year by removing the egg masses before next spring. Removing egg masses can potentially prevent the hatching of up to 1000 caterpillars per egg mass, and therefore lower the overall negative impact to trees on your property caused by defoliation.
When is the best time to remove egg masses? You need to remove the eggs before they hatch in April 2022. If you can, wait until the fall 2021 to remove the egg masses. The reason for the wait is that beginning now and into August and September, tiny, non-stinging wasp might parasitize the egg masses. Waiting to remove or destroy egg masses until after leaf fall/the first hard frost can allow this beneficial wasp an opportunity to build up its numbers.
There are also reports of white, rice-sized cocoons on tree bark and these may be the cocoons of the parasitic wasp. Please do not destroy these little white cocoons. They will do no harm to your tree and might be hosting the LDD moths predator wasps.
Here are some photos of the egg masses, parasitoid wasps, and the rice-sized cocoons:
There are also various tutorials on how to remove egg masses are available online including these from the City of Toronto:
Note that some of the egg mass can be located high up on trees and structures. Be careful when removing egg masses and don’t put yourself in a precarious position. Watch for tripping, falling, and power line hazards. Some private tree care companies can be hired to provide this service at heights.
*The Entomological Society of America (ESA) has withdrawn this common name but no new name has been adopted. For the interim, we will adopt the scientific name LDD (for Lymantria dispar dispar) and phase out the use of the old name in our communications.