You may have noticed large, silky webs with caterpillars inside on your trees and bushes lately. These are likely created by fall webworms (Hyphantria cunea).
In this post, we’ll discuss some natural ways to get rid of them. We’ll also provide tips on how to prevent them from taking over next year.
What Are Fall Webworms?
Often confused with eastern tent caterpillars that mostly show up in spring, fall webworms are a common sight in the northern United States and Canada in the late summer through early fall.
They’re the larvae of a moth , and they build noticeable webs in ornamental trees and shrubs.
The good news is that they’re not harmful to people or pets. The bad news is that they can be a real nuisance, and eat the leaves of many trees and bushes.
The caterpillars are identifiable by their yellow or pale green body with yellow stripes down their sides and dark stripes down their backs.
The nests are made of silk, and the caterpillars cover themselves with the webbing to protect themselves from predators and to overwinter. You’ll mostly see these nests on leaves at the end of branches.
They’ll also pretty much munch on any tree they can find, except conifers. But they seem to prefer the leaves of oak, ash, and hickory trees.
Adult fall webworm moths are mostly white and have hairy bodies. They also have dark spots on their wings.
How to Get Rid of Fall Webworms Naturally
These pests are not the pickiest eaters, but there are a few things you can do to keep them away or make your yard less appealing to them.
1. Parasitic Wasps
These wasps are natural enemies of the webworms, and they’ll lay eggs inside the pests’ bodies, which will then hatch and eat the caterpillars from the inside out.
Sounds pretty gross, right? But it’s a completely natural way to get rid of these pests, and it’s really effective.
You can attract predatory wasps by providing them with water and planting flowers and herbs that they are attracted to.
Another way to keep web worms out of pecan trees, fruit trees, and others is to attract birds to your yard.
Birds are natural predators of caterpillars, and they love to feast on webworms and their eggs. So put up a bird feeder, or plant some trees and shrubs that will provide them with food and shelter.
You can also try making your own DIY bird feeder. There are lots of different tutorials online, so you can choose the one that’s best for you.
And don’t forget to put out some fresh water for the birds to drink, too!
You may have seen these little critters in nests on your trees this fall. But before you reach for the toxic pesticides, consider using a natural product like spinosad.
Spinosad is derived from a naturally occurring soil bacteria, and it’s effective against a range of pests, including fall webworms. This is a good brand.
4. Bacillus thuringiensis (Bt)
This is a good choice to control webworms if you have a large infestation, and it’s something you can do yourself.
Bt is available as a powder or liquid; you can buy it online at some garden stores. It kills the caterpillars by forming holes in their gut wall.
Once they eat the Bt, they will die within a few days.
5. Neem Oil
Another great natural treatment for webworms is neem oil. This is an all-natural product that is effective against many pests, including fall webworms.
Moreover, you can buy a ready-to-use neem oil solution at most garden stores, or you can make a DIY web worm spray by mixing one tablespoon of cold-pressed neem oil with a gallon of water.
6. Poke Holes in the Nests
You can also kill webworms organically by poking holes in their nests. Doing this will expose them to predators such as birds and wasps.
7. Soapy Water
Another excellent home remedy for webworms is soap and water.
Fill a bucket with some dish soap and water. The ratio is two tablespoons of dish soap to a gallon of water. Next, pull down the branch with the nest and submerge it in soapy water.
You can also put the soapy water into a spray bottle and spray the mixture onto the webs. The soapy water will kill the web worms.
Pruning affected branches can help eliminate any fall webworms that might be hanging around.
Once the branches fall to the ground, stomp on the nests to squish the caterpillars. Pruning will also encourage new growth and make your tree healthier overall.
9. Vegetable Oil
Furthermore, treat webworms in trees with vegetable oil.
All you need to do is pour some vegetable oil into a spray bottle and use it to saturate the nests. The critters inside will suffocate and die.
10. Debug Tres Insecticide
Debug Tres insecticide is a natural webworm killer. This product contains Azadirachtin and neem oil, and it’s effective against a variety of pests.
All you need to do is mix it with the appropriate amount of water and spray it on the affected areas.
11. Horticultural Oil
Finally, you can try using horticultural oil or dormant oil. This is a good brand and it’s safe to use, even if the affected trees are close to your house.
It functions as an insecticide by suffocating the pests. It works on the larvae and eggs. But, you must completely saturate the pests and eggs for it to work properly.
Follow the instructions on the bottle.
So, you’ve discovered fall webworms in your garden and on small trees in your yard, and you’re not sure what to do.
The home remedies and natural products above can help eliminate or control the problem, one way or another.
Try out a few or maybe all of them to get rid of the critters for good. Pruning and monitoring trees using store-bought or homemade insecticides will help prevent webworms from coming back.