Sasha CampbellEver notice those large, silvery-gray, tent-like webs in the branches of trees around your yard? While several insects can create webbing in trees, tents located in branch crotches during spring are often made by Eastern tent caterpillars.
These little critters can do a great deal of damage to trees and shrubs if you let them get out of control. The good news is that you don’t need to douse your yard with chemicals to get rid of tent caterpillars.
You can try several natural methods to eliminate these pests and their unsightly tents. This article explores easy, natural solutions for tent caterpillar infestations.
Identification
Eastern, Western, and Forest tent caterpillars are the most common types.
Eastern and Western species build silken tents in tree branches. In contrast, forest tent caterpillars form silken mats on bark and branches instead of making enclosed tents.
As larvae of moths, tent caterpillars feed on trees like cherry, apple, oak, and plum [1]. If you see webbing in your trees and groups of caterpillars crawling around on the trees, you likely have a tent caterpillar infestation.
These caterpillars are most active in spring when they begin building their silken structures in trees.
How to Get Rid of Tent Caterpillars Naturally
Below are some home remedies and natural methods to control these hairy caterpillars.
1. Diatomaceous Earth
This natural powder can help control tent caterpillars. It damages their protective outer layer, which can lead to dehydration over time under dry conditions, since moisture reduces its effectiveness.
Apply dry food-grade diatomaceous earth directly to caterpillars and areas where they travel. Reapply after rain or heavy dew.
2. Spinosad
Spinosad is a natural insecticide that targets chewing insects, such as tent worms. It disrupts their nervous systems, causing paralysis and ultimately death.
Purchase spinosad concentrate and mix according to the directions on the product label. Popular brands include Monterey Garden Insect Spray and Bonide Captain Jack’s Deadbug Brew.
Thoroughly spray the critters, their nests (or mats), and the surrounding foliage. Best applied when caterpillars are actively feeding on foliage.
3. Garlic and Soap Spray
Garlic has strong natural compounds that many insects dislike. This makes it a useful repellent for tent caterpillars when applied early in an infestation.
To make the spray, crush 4 to 5 garlic cloves and soak them in 1 quart of water overnight. Strain the mixture, then add 1 teaspoon of mild liquid soap to help it stick to leaves and caterpillars.
Pour the solution into a spray bottle and apply it directly onto caterpillars and around infested branches. It works primarily as a deterrent and is best used alongside stronger methods such as Bt or spinosad.
Reapply every few days or after rain for continued effect.
4. Neem Oil
Neem oil is an organic pesticide that you can use against caterpillars in your garden and other areas outside your house.
It is most effective on young larvae and should be applied early in an infestation for best results.
To make a DIY tent caterpillar spray with neem oil, combine 1 to 2 tablespoons of neem oil with 1 gallon of water and a small amount of mild liquid soap as an emulsifier. Next, shake it up and spray the affected areas.
5. Pruning
Pruning infested branches and leaves is an easy way to manually remove tent caterpillars from trees.
Go out and look for the nests in trees, especially in spring and early summer. Look for nests in the branches of susceptible trees, such as crabapples, cherries, and apple trees.
Once you spot an active nest, prune the branch it’s on. After pruning, dispose of the branches, leaves, and nests.
6. Pick Them Off
As the caterpillars hatch, check tree branches for nests or mats and destroy them. Also, search for and manually remove their egg cases.
Use a pruning shear to cut the branch holding the tent or mat, so it falls to the ground. Once on the ground, destroy or dispose of it in a bag.
You can also scrape off the eggs that the adult moths lay. Use a sturdy putty knife or similar tool, and drop the egg cases into a bucket of soapy water to suffocate the eggs inside.
7. Natural Predators
Many natural predators prey on tent worms, helping control their populations.
Many birds will snack on the caterpillars, especially when they leave the tent to feed. Attracting birds is also good if the caterpillar nests are in tall trees.
Some bats may occasionally feed on caterpillars. Moreover, tiny wasps, such as the braconid wasp, lay their eggs inside caterpillars. The wasp larvae hatch and eat the caterpillar from the inside out.
Other natural enemies may include ground beetles, predatory bugs, and parasitic flies and wasps.
8. Bacillus thuringiensis
Bacillus thuringiensis (Bt) can also help control tent caterpillars. When the tent worms ingest Bt, they die within a few days.
You can find Bt as sprays and drenches for plant applications. The Bt kurstaki strain is most effective for tent caterpillars.
9. Soapy Water
One of the simplest methods to kill tent caterpillars and webworms is to thoroughly spray them with soapy water. Mix 2 tablespoons of liquid soap (Dawn dish soap is okay) into a quart of water in a spray bottle.
Spray enough directly onto the caterpillars so it thoroughly soaks them.
Direct contact with soapy water can damage the caterpillars’ protective outer layer. This breaks down their protective coating, leading to dehydration.
10. Destroy Nests Early Morning or Evening
For the best results, remove or destroy tents early in the morning or late in the evening. During these times, most of the caterpillars will be gathered inside.
11. Horticultural Oil
Horticultural oils are most effective against overwintering egg masses and newly hatched larvae. This treatment is a very effective organic control method.
Apply according to label directions during dormancy or when eggs and young larvae are present for best results.
12. Homemade Pepper Spray
Another great home remedy for many pest problems is pepper spray.
Pepper sprays may help discourage feeding and can act as a repellent. However, they are generally less effective than Bt or spinosad.
Blend 10 hot peppers with 1 gallon of water, heat briefly to release oils, cool, strain, and add a few drops of liquid soap before spraying.
Spray it directly onto the critters.
13. Sticky Tree Bands (Trunk Barrier Bands)
Sticky tree bands are an easy, natural way to control these hairy caterpillars. The wraps create a physical barrier around the trunk, preventing caterpillars from climbing upward.
Follow the instructions that come with your purchase for applying it to the trees.
Takeaway
You can manage tent caterpillars without harsh chemicals.
Use natural sprays, manually remove them, and explore other non-chemical methods to keep them at bay. Encouraging natural predators like birds can also help keep populations under control.
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