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You’re here because tent caterpillars are eating your trees right?
I’m not surprised caterpillars are a big pest for trees and especially fruit trees.
A large nest of tent caterpillars can quickly defoliate your trees, but don’t worry I have a very easy way to kill the caterpillars in your trees that uses just ONE easy ingredient you have in your home right now.
If your trees are larger and more mature the damage the caterpillars will do normally won’t kill your tree. Healthy trees will simply grow back a new set of leaves.
This will still cause the tree stress and possibly the loss of its blossoms and of course means you’ll also lose your fruit harvest.
However, if your trees are younger the stress of losing their leaves can really set back their growth or worse yet, kill the tree.
I remember when our apple trees were younger. The first year they started to produce well we had a large infestation of tent caterpillars.
It seemed like they lost their leaves overnight and the stress caused them to drop all of the young apples that had just started to form.
We lost our apple harvest that year and I knew I never wanted to let that happen again.
I found a way to organically kill the tent caterpillars in our trees and I can’t wait to share it with you so you can protect your trees too!
To control a pest in your garden you need to understand its life-cycle.
There Are 3 Kinds Of Tent Caterpillars
Depending on where you live you could have any of these 3 types of tent caterpillars. While they look different from each other they do the same type of damage to your trees.
Don’t confuse them with the fall webworm that can be seen in trees in the late summer and early fall.
Eastern Tent Caterpillars
The Eastern Tent Caterpillars are black with a white stripe down the center of their back and a row of light blue spots along each side.
Their favorite trees to eat are cherry, apple, and crabapple but will also feed on shade trees.
Western Tent Caterpillars
The Western Tent Caterpillar is yellowish-brown with a row of blue and orange spots along their back.
They feed on cherry, apple, plum, willow, birch, poplar and oak trees.
Forest Tent Caterpillars
The Forest Tent Caterpillar is similar looking to the Eastern Tent Caterpillar. They are black with white keyhole-shaped spots along their back.
Unlike other tent caterpillars that make nests in the forks of trees, they create a silk mat along the surface of branches.
Tent caterpillars are one of the most social types of caterpillars and these are part of the moth family Lasiocampidae the main variety we have in our area is the eastern tent caterpillar.
The female moth lays her eggs early in the spring in clusters of 200 to 300 eggs. These eggs grow quickly and in 3 weeks the caterpillars will be fully formed.
These baby caterpillars stay in a dormant state until the following spring when they hatch very early in the spring. Their hatching is timed to match the new budding of the trees.
After they hatch the little caterpillars start to build a silk nest. These start out very small and are made larger as the caterpillars grow.
It is best to start checking your trees in the early spring for these small nests. Look especially at the forks of the tree branches as these are their favorite place to build nests.
The young caterpillars come out 3 times a day to feed.
Normally this is just before dawn, mid-day and just after the sun has set. The caterpillars leave their nest together and travel to a feeding site and then return to their nest when they have finished feeding.
It is important to know this because my method of killing tent caterpillars works the best when they are all in the nest together!
In the last stage of the caterpillar’s life they leave each other to find a place to form their own cocoon. After forming a cocoon the moths will hatch in about 2 weeks time.
The moths are nocturnal and you have likely noticed these medium-sized brown moths flying around at night.
They breed not long after hatching and the females die not long after laying her eggs.
Now that you know the life-cycle of the tent caterpillar it makes much easier to control.
How To Kill Tent Caterpillars In Your Trees
A very common way of destroying tent caterpillar nests is to burn them with a small propane torch.
This is the way I learned growing up and I’ve seen many people kill caterpillar nests this way. But there are problems with this method.
- Burning the caterpillar nests can damage your tree and leaves large ugly black patches behind. I’ve done this before and it really does look ugly! A way around this is to cut out the branch after you’ve burned it. But this again damages the tree and what if your nest is up high in the tree or on larger branches? You really don’t want to cause a lot of damage to your trees. After all, isn’t that what you’re trying to protect them from?
- Burning the nest with a torch can also be difficult to do when the weather is windy as small torches are easily blown out. If the nest is high up in your tree climbing it or using a latter isn’t the safest idea when using a torch either.
So the really easy way that we came up with for killing tent caterpillars is simply vegetable oil!
Really, it’s that simple!
The key to making this work is knowing the caterpillars life-cycle. You need to wait until the caterpillars are all in the nest together, then spray the nest well with vegetable oil.
This works because insects breathe through their skin. When they are coated with oil they can’t breathe and die very quickly.
You can use new vegetable oil but I’m a pretty frugal person so I save our used oil from the deep fryer.
Just pour the leftover oil into a spray bottle and keep it on hand for when you spot these caterpillar nests in your trees.
I love using this heavy-duty spray bottles. They are so handy in the garden because they are a stronger plastic than most spray bottles and have easy to use measuring marks on the side.
The Benefits Of Using Vegetable Oil
- It kills the caterpillars quickly and doesn’t leave any nasty black spots in your trees. The nest if left alone will fall apart and break down quickly on its own.
- It is also so much easier to spray the nest that is higher up in your tree with the oil then it is to try to burn them with a torch.
Would you like to see just how well this works?
Watch my video where I show you just how easy this method of controlling caterpillars in my fruit trees really is. I just love finding easy and safe ways to control pests in my garden don’t you?
Other Ways To Control Tent Caterpillars
While spraying the nests with vegetable oil is my favorite way to control these pests, once they outgrow the communal nest it doesn’t work.
But there are still easy ways to get rid of tent caterpillars on your trees and yard.
How To Get Rid Of Tent Caterpillars With Dish Soap
Spraying caterpillars with dish soap is another easy way to get rid of them quickly.
The key to making a dish soap spray work is to not let the soap foam up to much.
Fill the spray bottle up almost full with water, then add 1-2 tablespoons of dish soap per gallon of water. Then finish topping up the water.
Give the sprayer a gentle shake to mix the soap in. This helps to suspend the soap in the water without it floating to the top as bubbles.
As you find the caterpillar nests you can spray them with this, but it also works very well when you have masses of tent caterpillars on your sidewalk and other areas.
Use BTK Spray
If your trees are being eaten by tent caterpillars but you can’t find a nest to destroy then using an organic BTK (Bacillus thuringiensis) spray is your best option.
This natural bacteria only harms caterpillars, it’s safe to use around birds and bees.
Simply spray the leaves of your trees with BTK and when the caterpillars eat it it will kill them.
Download a tip sheet to help you remember how to spot tent caterpillars in your garden and control them safely!
Are you fighting with cucumber beetles in your garden? See my quick and easy way to get rid of them!
Kim Mills is a homeschooling mom of 6 and lives on an urban homestead in Ontario, Canada. Blogging at Homestead Acres she enjoys sharing tips to help you save money, grow and preserve your own food.