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Are cankerworms dangerous?

Are canker worms dangerous to trees? 

When canker worms are born, they’re hungry. They eat what’s around them, and that usually means the leaves they’ve lived on while in their eggs. If a canker worm infestation is big enough, it could completely defoliate a tree. Typically, even in these rare circumstances, that won’t kill the tree. The tree will grow it’s leaves back.


That being said, if the defoliation is significant, your trees might be at risk of other issues. If your trees are working hard to replace their leaves, they might have a harder time fighting off other diseases or insect infestations. This becomes harder for a tree if it has to fight to rebuild itself season after season.

Of course, if your tree is already healthy (with lots of water and the right fertilizers) it will be better able to fight off the effects of defoliation and disease. If you want to give your tree additional help, be sure to add a tree band. Tree bands are the best way to prevent next Spring’s canker worm infestation.

Are canker worms dangerous to humans? 

Not really. They can’t bite you or spread disease. That being said, I’m sure you’ve heard stories of joggers on the Booty Loop twisting an ankle while trying to avoid them. Springtime bike riders in Dilworth might also be distracted by these pesky inchworms, too. While a canker worm has never hurt anyone intentionally, they might have resulted in an injury or two.

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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