WET SUMMERS AND MILD, MOIST AUTUMNS ARE FAVORABLE TO WINTER MOTHS AND MAY INCREASE THEIR POPULATIONS DRAMATICALLY.
In early spring, stake out favorite daytime hangouts like inside buds and leaf clusters. At night use a flashlight to look for dubious characters on the outsides of leaves.
Search tree trunks for wingless females in October through January.
Look for devastated flower buds and early dropping of petals from fruit trees such as cherry trees.
It is really helpful to keep a record of what you see and what you don't.
These caterpillars should be one of the only typical-looking inchworms around in early spring.
Then, figure out which stages of the winter moth lifecycle you can impact. If you're anxious to get into the yard during the winter, search out females on warm, winter evenings. These wingless females are easy to catch. Look for the cloud of male moths around the tree trunk waiting for a chance to mate.
As with most pests that cause leaf loss, established trees can bounce back from up to 25% leaf loss for one or two years repeatedly.
Consider that winter moth is a cyclic criminal. It's here one year, gone the next.
Finally, make a plan.
If the danger level is low enough, this is a good strategy. Remember to consider the health of your tree and its ability to withstand some leaf loss. -Trees that have been established for more than a couple of years are quite able to defend themselves. Don't feel like you have neglected your tree if you decide not to do anything. Winter moth is subject to many natural predators and parasites.
Your tree can defend itself if it's strong and healthy. Check with your local tree service if you aren't sure how to water or fertilize your tree.
Roadblock female winter moths on their way to mate and lay eggs. Put a 3-4" wide sticky barrier on tree gauze around the trunks of infested trees. Both the sticky stuff and gauze can be bought at garden stores for less than $10.
A gang of killers has increased its numbers in recent years and they are hungry for winter moth larvae. They are parasitic flies that trick winter moths into eating their eggs by placing them near recently munched on leaves. As the egg hatches inside the winter moth, it literally eats the moth inside out.
-Bacillus thuringiensis (B.t) is deadly to caterpillars, yet it's less toxic to other wildlife than most insecticides. It works best on young caterpillars, so spray in early spring on a cloudy but warm day. (Sunlight breaks down B.t.) -Look for products in home and garden stores that contain B.t. and are registered for use on caterpillars.
-Don't forget to read and follow directions for use, storage, and disposal, whenever a chemical is used.
Remember to check with your local tree service for advice, sprays, treatments and maintenance plans for the health and well being of your plants and trees.