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Is there a spray for canker worms?

If you have a canker worm infestation you can apply chemicals- but you have to catch the infestation early. The best time to spray pesticides on your trees is when the canker worms are still young (less than a half-inch long), two weeks after they’ve hatched. It can be difficult to detect this before it’s too late. This is usually in the first two weeks of April- but timing is everything.

By the time we typically notice canker worms (when they dangle from the trees and get caught in our hair) it’s too late to spray for canker worms. Charlotte's city arborist is watching for the signs of hatching and will decide, on a yearly basis, if spraying will be helpful.

Of course, the best way to manage an infestation is to prevent it by using tree bands. In fact, Charlotte has a very active tree banding program in place, to keep our tree canopy healthy and beautiful.

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Why do canker worms hang from trees?

A canker worm is actually the larval form of a moth. When you see a canker worm, it is a cute little baby moth, enjoying life and exploring it's new world. They are hanging from trees because they are trying to get into the ground below the tree. When they reach the ground they burrow in and create a cocoon. There they wait, transforming into their adult form. They will hatch from their cocoons sometime in the fall, when things start to cool off. At that point they will breed. The females (who are wingless) crawl up the tree to lay their eggs. That way, next year, there will be plenty of icky inchworms hanging from trees and getting in your clothes. This is why the best way to handle canker worm infestations it to band your trees. This prevents the female moths from crawling up the tree and laying their eggs.

When do canker worms go away?

Every Spring, after all the canker worms have slid down their silk lifelines, they burrow into the ground, form a cocoon and wait until fall before they emerge again. This usually takes a couple weeks before they’ve completely gone away. But they never really go away. They emerge in the fall, once the cold weather begins, as a moth. When they hatch these horny buggers breed. As is typical, the males fly away, leaving the wingless mothers crawl up the tree and lay their eggs. The eggs then lie in wait until next Spring, so they can annoy you again. This is why tree banding is so important. If you can catch these moths as the crawl up a tree’s trunk, they won’t be able to lay their eggs. That means, next spring, there will be less inchworms dangling from trees, getting caught in your hair, and hiding under your shirt.

Is there a natural way to get rid of canker worms?

There are a couple of natural ways to get rid of canker worms. For one, you can use a bacteria-based pesticide. These pesticides only affect certain insects (like canker worms) and won’t hurt other, beneficial insects (such as bees). This kind of targeted attack can be tricky. You have to apply this pesticide early in their life cycle. This is usually before we see them hanging down, on their silk, from the tree. A another natural way to get rid of canker worms is through predators. There are several creatures that eat canker worms. Some birds, insects and even rodents will eat them. The problem is the canker worms strategy to survive is through their large numbers. There are so many canker worms that predators can’t possibly eat them all. Another natural approach to canker worms is to let them do their thing, but take care of the tree. While most trees will be able to replace their leaves, after the canker worms go to town on them, this is much easier when the tree is healthy. Make su