We all love those tall, mighty oak trees. They truly are a sight to see, and they are not only beautiful but bountiful and do so much for our environment. But the truth is – we’re not the only living thing that loves them. Caterpillars absolutely adore oak trees, along with wildlife and insects – but our oak trees don’t adore them back.
Caterpillars eat the foliage of oak trees and their webs inhibit tree growth. To get rid caterpillars on your oak, you should have the oak tree cared for by a professional to remove the caterpillars. You should also attract natural caterpillar predators, such as birds, to flock near your oak tree.
Today, we’re going to discuss why caterpillars are on your oak tree and what you can do to get rid of them! Keep on reading to find out more.
Why Are Caterpillars on My Oak Tree?
During the spring and summer, you may see thousands of caterpillars on your oak trees. Yup, thousands. An oak tree is a host plant to many species of caterpillar, and when the weather starts to heat up – it is caterpillar season.
Caterpillars tend to migrate towards oak because of all the benefits oaks have to offer. Oak trees offer shade, they offer shelter, and they offer an endless amount of food that will regenerate as long as it doesn’t get destroyed by a caterpillar infestation.
Caterpillars typically appear from the spring to the fall to feed on leaves. Once they literally stuff themselves with leaves and grow plumper, they then hang from the tree, spin their cocoons, and will be dormant from late fall to early spring – where they then emerge as butterflies.
I mean, the truth of the matter is – oak tree leaves are part of a caterpillar’s life cycle, and they will find safety in your oak trees so that they can cocoon.
So – why would we need to get rid of caterpillars?
Caterpillars Are Bad for The Health of Your Oak Tree
I know; I feel bad for the caterpillars too. They are small, vulnerable little creatures that only are looking to feed and feel safe. I mean, technically, that’s what every animal wants, right? Okay, sorry to get all philosophical here, but it’s the truth!
And the other thing is – we’ve all grown up with the “caterpillars turning into butterfly metaphors” as part of our life – but the truth of the matter is – as beautiful as they become, caterpillars can do a lot of ugly to our oak trees.
Since both caterpillars emerge and oak trees come out of their dormant stage in the spring, the caterpillars can be detrimental to the health of the tree, especially if they are eating all the leaves and buds right when it’s waking up.
The problem with caterpillars is that it can lead to tree-wide destruction and make the oak tree lose all its leaves. The webs of caterpillars can be wound so tightly around branches that the oak tree loses the necessary air and sun needed to survive.
At face value, caterpillars are not so bad, and the tree can generally recover – however, the problems start to occur when there is an infestation, and the best way to avoid that is by prevention.
If your not sure if it’s caterpillars in your oak tree, you can view our checklist for what may be wrong with your oak tree here.
Simple Tips to Get Rid of Caterpillars in Your Oak Tree
There are a lot of things that you can do right now to protect your oak trees from caterpillar damage and pests in general. There are also ways to get rid of them – if they already became a problem. Either way, you should act quickly to avoid any unnecessary damage to your tree.
9. Remove Caterpillar Webs Off The Oak Tree
If you start to notice a lot of webbing around your oak tree – there is a good chance it’s caterpillars and not spiders! This is one that you can call a professional removal service for (to reach those high up branches), but removing the caterpillar webs from your oak trees may be something that needs to be done.
If you see a few caterpillar webs, there is a good chance your oak tree will be okay; however, if you start seeing more webs, and more webs, and more webs – it’s time to take some action because you will have an infestation on your hands soon.
Removing the caterpillar webs should be done in the winter when the caterpillars are dormant. Removing the webs can be done by pruning the branches of the oak tree that the webs are on. Further, if you see any larvae on trees, it may be a good idea to prune those branches as well.
Cutting off any leaves that have webbing on them is also a good way to prevent an infestation and get rid of your caterpillar problem.
8. Spray Your Oak Tree With Neem Oil
If you rather go an even more natural route – you can spray the oak tree with neem oil to get rid of the caterpillars. Neem oil needs to be diluted and should be mixed with water and something like dish soap – as an emulsifier and then can be sprayed onto the infected areas of the oak tree.
Neem oil is a natural product that can be found organic. Depending on the type of neem oil used, it can also be utilized as an indoor pesticide.
If you are looking for a high quality neem oil, check out Organic Neem Bliss 100% Pure Cold Pressed Neem Seed Oil.
7. Use a Non-Toxic Pesticide On The Oak Tree
Using a pesticide such as Bacillus thuringiensis can help with your caterpillar problem but will not be harmful to the tree and will not be harmful to any other insects unless specifically listed on the bottle.
Bacillus thuringiensis is a naturally occurring bacteria in many soils. So it is typically natural and will not harm your tree.
Using a trigger spray bottle or pressure tank sprayer, mixing Bacillus thuringiensis with water and applying it to the affected areas of the oak tree will help control, prevent, and get rid of any caterpillars.
If you are looking for Bacillus thuringiensis, you can try out this product, Monterey LG6332 Bacillus Thuringiensis Worm & Caterpillar Insecticide.
6. Remove The Caterpillars Off Your Oak Tree
One of the first things you can try to get rid of caterpillars is to pick them off. I know, chills. But, If you are noticing more than usual, it may be time to take some action, and if you’re really not sure what to do first – this may be just the thing.
Now, before we get into it, we reccomend contacting a professional to inspect (and remove) the oak tree for the specific type of caterpillar on your tree. At the end of this article we review some of the common types that you may have on your oak tree.
Either with a pair of gloves and your hand, or even if you need to use a stick or branch to lift the caterpillars, move the caterpillars off the branch and tree and place them far away from your oak tree.
You may need a ladder to reach high up spots as well. However, this will ultimately help your issue, plus it will protect the caterpillars if done carefully.
Another way to do this would be to cut the branches you see the caterpillar is on and then place the branch away from the tree. There is a good chance the caterpillars will stay on the branch and will not need the tree.
5. Spray The Oak Tree With Dish Soap and Water
Another alternative method that you can try rather than using the two sprays above is by mixing just dish soap and water into a bottle and spraying it onto the affected area.
Dish soap will not kill the caterpillars, but it will make the leaves and tree too slippery for the caterpillar to stay attached and feed on. Dish soap and water are a great preventative to deter caterpillars away from your oak trees.
Whether you already have a caterpillar problem, or you are trying to prevent one from happening – spraying dish soap along the bottom trunks of your trees and on the branches can help solve the caterpillar problem before it even starts.
4. Make a Garlic and Hot Pepper Caterpillar Insecticide
Another natural way to deter caterpillars is by making your own garlic and hot pepper insecticide and spraying it around your oak trees.
A mixture of garlic and hot pepper (cayenne pepper or hot sauce), oil, dish soap, and water can be mixed together and sprayed onto your oak trees. This mix will deter caterpillars and other insects because it is strong smelling and will overwhelm the senses of the insects, making it an unsafe spot for them to feed and cocoon.
This mix will not kill any caterpillars but make your oak trees a no trespassing zone for caterpillars and other pests.
3. Plant Caterpillar Repellent Plants Near Your Oak Tree
A way to prevent caterpillars altogether is to get ahead of the problem – and plant caterpillar repellent plants nearby your oak trees.
Especially if you have newly planted or young trees, a great way to prevent a caterpillar infestation is to protect your trees from caterpillars altogether. Planting plants like Mugwort, Sage, Lavender, Mint, and Wormwood around your trees – can really help stop caterpillars in their tracks!
All of these plants are natural insect repellents and pest repellents and will not only help your caterpillar problem but other pest problems in general.
When planting these plants, just make sure to create a wide barrier around your trees, but far enough away so that your oak tree isn’t competing with these plants for nutrients. If the oak tree is young, it is important to maintain good health for the tree by allowing it to have the ample amount of water, air, and nutrients it needs to survive.
2. Add Duct Tape to The Trunk of Your Oak Tree
Another great way to prevent caterpillars from even getting up into your oak tree business is by wrapping portions of your oak trees with duct tape and the branches.
Duct tape will make the branches and trunks of the oak trees slippery – which will be a complete no, no for caterpillars and for butterflies and moths to lay their eggs on.
Although this may not be full-proof, duct tape can definitely help slow down any caterpillar infestation and will definitely help with prevention.
Just make sure not to duct tape where leaves are forming – as that will cut the air supply and can do more harm to your tree than good.
1. Attract Natural Predators Like Birds to Your Oak Tree
Okay, this may seem out of sorts – but it actually can be a very effective way to get rid of your caterpillar problem.
Birds love to eat caterpillars, and as sad as it may be to see the caterpillars go, you will be feeding the wildlife and will be saving your tree so that it can stay strong and tall for wildlife to live in.
Attracting birds to your oak trees can be as easy as hanging a bird feeder from one or two of the branches. If there is anything a bird loves more than seeds – it’s caterpillars. So attracting them to the affected trees can be a way to get rid of the caterpillars altogether.
This is actually my favorite method because genuinely, you can install a birdhouse on or near your oak tree and boom. Over time it will work and you get to attract beautiful bird to your home.
What Types of Caterpillars Live on Oak Trees?
There are four common types of caterpillars that may be living on your oak trees, and all of the methods above, or a combination of a few, may be used to get rid of these types of caterpillars.
Pink-Striped Oakworm Caterpillars
Pin-Striped Oakworm Caterpillars are hairless, with a bigger head and smaller yellow to green body. When this caterpillar matures – it starts to turn black.
Pink-Striped Oakworm Caterpillars love to feed on oak tree leaves, especially the newly sprouted ones. They will eat the leaves until the veins and will eventually consume the entirety of the foliage.
Oakworm Caterpillars can damage entire oak tree canopies – so if you notice these bugs, it’s good to get rid of them as soon as possible.
Above is an image of what the Pink-Striped Oakworm Moth will turn into. Unfortunately, the females will continue to lay more offspring in the moth stage, most likely in your oak tree.
The most easily recognizable caterpillar to its name, the Yellow-Necked Caterpillar, is yellow with black stripes.
This late summer and early fall, emerging Yellow-Necked Caterpillars will eat the leaves down to its veins. They will eat until they are nice and plump, and ready to cocoon. The caterpillars will chomp at each section of an oak tree’s leaves and will continue with this eating pattern until they eat the entire canopy!
If you start to notice branches’ leaves disappear – there’s a good possibility that you have a Yellow-Necked Caterpillar infestation – and it’s time to act fast.
A hairy caterpillar with a reddish-brown body, and smaller head, Tent Caterpillars are known for making tent-like webs.
Tent Caterpillars show up early in the spring and will create spooky, silky, spider-like webs that almost mimic a tent or large cocoon. Their webs are made to protect the caterpillars and to keep them from falling off high branches in your oak trees.
If you happen to see a web and want it removed, make sure to call a professional – as the webs can house hundreds of caterpillars.
The Leafroller is a smaller caterpillar with a darker-colored head and a green or brown body. These caterpillars also make silky webs like Tent Caterpillars, but the difference is – they roll leaves into their webs!
Leafroller Caterpillars will form large webs around large sections of oak tree leaves so that they can feed on them safely within their web. If these webs get out of hand, they can defoliate the entirety of the oak tree canopy.
That’s a Wrap!
Although cute from a distance, caterpillars can be one of the most harmful pests to your oak trees. They love to eat the oak tree’s foliage and can eat the entirety of the canopy if given a chance to.
When the leaves of the tree are eaten, the lack of leaves can actually stunt the growth of the oak tree and can, in turn, make your oak tree unhealthy or eventually kill it.
Oak trees need leaves, as well as all trees because it is their main source of making food. Without their leaves, oak trees may not survive.
To get rid of the caterpillars, there are many simple things that you can try that will not harm you or the trees, and the best way to avoid a caterpillar infestation – is to prevent it from happening in the first place.
“Tent Caterpillars – How Do I Get Rid of Tent Caterpillars?” Texas A&M AgriLife Extension Service, 4 Mar. 2019.
Roland, J. (1993). Large-scale forest fragmentation increases the duration of tent caterpillar outbreak. Oecologia, 93(1), 25-30.
Miliczky, E. R., & Calkins, C. O. (2002). Spiders (Araneae) as potential predators of leafroller larvae and egg masses (Lepidoptera: Tortricidae) in central Washington apple and pear orchards. Pan-Pacific Entomologist, 78(2), 140-150.
Wagner, D. L. (1997). Caterpillars of eastern forests (Vol. 96, No. 34). US Department of Agriculture, Forest Service, Forest Health Technology Enterprise Team.