Tomato hornworms are one of the most prevalent pests that garden owners will know all too well. They can cause a lot of damage, especially to pepper and tomato plants (hence the name), so here are some simple ways that you can get rid of them.
Tomato hornworms are found globally in temperate regions where tomatoes or tobacco are produced, such as the north of the United States.
Hornworms come in two varieties. The tomato hornworm and its cousin, the tobacco hornworm differ from the others in that it has a red horn and diagonal white stripes instead of V-shapes.
Because they are so similar, people frequently get them mixed up. However, the tomato and tobacco hornworms feast on the same plants, it makes no difference which you have in your garden; you are able to get rid of them with similar methods.
Tomato hornworms are roughly four inches long and have seven white v-shaped stripes that run diagonally across their bodies. When you approach near to them, you’ll notice enormous black or red horns protruding from their back.
The most visible stage of these pests is the juvenile larval stage, when large caterpillars may be spotted in your plants, but they eventually mature into a five-inch-winged moth.
The hue is the clearest way to tell that these are tomato hornworms. Tomato hornworms are the right shade of green to go with tomato leaves. Tomato hornworms are the best at disguising themselves among plants.
The Lifecycle Of A Tomato Hornworm
The lifetime of tomato hornworms is divided into four stages. In general, the larval stage is the one that we see most on our plants, although a lot happens before and after that.
Gardeners can benefit from understanding how these destructive insects thrive and reproduce.
Stage One
The adult tomato hornworm is known as a sphinx moth and lays eggs on nightshade plants including tomatoes, eggplants, peppers, and potatoes.
The larval stage is what most gardeners observe. This is when you will notice a big tomato hornworm on your tomato plants.
Despite their enormous size, the giant worms aren’t adults. This level is divided into five phases known as instar stages. The larval stage lasts about three weeks, and a typical tomato hornworm can grow to be five inches long and weigh ten kilos.
Stage Three
The tomato hornworm is a big caterpillar. When the weather turns cold, they overwinter as big, reddish-brown pupae in the soil.
Stage Four
The adult stage is the final stage of the cycle. The pupae hatch in late spring, and a big moth is known as the five-spotted hawk moth or the sphinx moth emerges.
This is the adult stage, and they feed on the nectar of various flowers from late at night until early in the morning.
They are difficult to identify since they are not active during the day while we are in the garden. The adults also lay eggs, which completes the tomato hornworm life cycle.
Telling The Difference Between Tomato Hornworms And Tobacco Hornworms
As previously stated, there are two types of hornworms: tomato hornworms and tobacco hornworms. Both as larvae and adults, they are physiologically similar yet clearly distinguishable.
Tobacco hornworm larvae have seven diagonal stripes on each side with a red posterior horn, whereas tomato hornworm larvae have eight chevrons on each side and a bluish-black horn.
The abdomen of a tobacco hornworm moth has six orange dots, whereas the abdomen of a tomato hornworm moth has five spots. Both species’ pupae are dark brown and feature a handle-like tongue case on the outside.
Hornworm pupae overwinter in the soil. Adults emerge in early June, and the majority of damage happens in July and later. Depending on the temperature, North Carolina has two to three hornworm generations.
How Tomato Hornworms Affect Plants
You’ll most likely notice the harm these bugs inflict before you see them crawling about your tomato plants. Tomato hornworms are notorious for their voracious appetites, defoliating whole plants in a matter of minutes.
Tomato hornworms’ favorite food is tomato plant leaves, as you could have imagined. They’re not picky, though, and will swiftly go on to chewing on plant stems as well.
They normally start at the tops of your tomato plants, creating gaping holes in the foliage or plain stem stumps.
Tomato hornworms will move on to the wonderful juicy fruits once they’ve stripped the plant of its beautiful foliage.
Their damage is comparable to that of other leaf-munching bugs, making it difficult to tell which bug you’re dealing with. Tomato hornworms, on the other hand, frequently leave big black droppings on what’s left of the leaves.
If you don’t happen to notice the big teeth marks in your plants, then you may spot the black droppings. If you notice any of these symptoms, you must act quickly.
How To Find Tomato Hornworms
Here are some ways that you can make sure that tomato hornworms are the perpetrators of the damage to your plants.
The first thing you should do is inspect your plants to see if there are any black droppings on the foliage. The droppings are left behind by the hornworms as they feast on the plants.
These pests are busiest at dawn, twilight, and night. This is when they come out to feed, and while their camouflage makes it a little more difficult to notice them, they thrash and move, so carry a flashlight when feeding and inspect your plants.
A UV lamp is the finest tool for detecting tomato hornworms. These bugs shine under a UV lamp, giving your plant the appearance of having bulbs on it.
Tomato hornworms aren’t afraid to cause havoc. They devour the leaves only on the surface, leaving enormous holes and open regions where they’ve consumed all of the plant content.
How To Get Rid Of Tomato Hornworms
Here are some ways that you can get rid of tomato hornworms in your garden. Some of these methods are straightforward but others will require a bit more time and effort.
Pick Them Off By Hand
Natural methods of managing and preventing tomato hornworms are, surprisingly, the most successful.
Picking these enormous green caterpillars from your tomato plants is the most natural way to remove them. This strategy is not unfamiliar to seasoned tomato growers.
They are not deadly to humans, despite their appearance. You can handle them without getting stung or bitten. You may either transfer them or dump them into a basin of soapy water to get rid of them permanently.
Because tomato hornworms mix in with the green foliage, finding them can be difficult. Spray your tomato plants with water to start them moving and make them easier to identify and trap.
You may also outfit yourself with gloves and a UV lamp and start looking for tomato hornworms at night. Their bodies will emit a green glow under the UV light, allowing you to readily capture and dispose of them.
Till The Soil
As previously stated, tomato hornworms overwinter in the soil before emerging as moths in the summer.
While they are not hazardous in their ultimate stage of development, they do lay eggs on weak tomato plants, restarting the deadly cycle. Tomato hornworms might become an annual nuisance as a result of this practice.
Tilling the soil at the start and conclusion of the gardening season is one of the finest strategies to avoid the cycle from restarting. This kills any remaining tomato hornworm pupae deep in the soil, preventing them from developing into egg-laying moths.
Most gardeners should add soil tilling into their pre-season gardening practice. It not only halts the tomato hornworm life cycle, but it also eliminates other overwintering tomato hornworms.
Many soil-borne illnesses persist in the winter months, and tilling stops them from spreading and infecting your tomatoes and other plants. It also loosens the soil, kills weeds, and eventually prepares the soil for a fruitful growing season.
Neem Oil
Neem oil may be your finest ally in the fight against pests. It’s a basic for most gardeners, so it’s widely accessible and, thankfully, not difficult to use.
Neem oil functions as a natural pesticide against several tomato pests, including aphids and whiteflies. It also works well against tomato hornworms. Some fungal illnesses can also be treated with neem oil.
Unfortunately, as with most things, there are some drawbacks to this strategy. While neem oil will not harm your plants, it will harm and discourage helpful insects.
As a result, when fighting tomato hornworms, it is critical to pick your tactics wisely. If you’ve worked hard to introduce a variety of beneficial bugs into your environment, using neem oil on your plants may be counterproductive.
Neem oil, when sprayed on tomato plants, forms a light coating on the leaves and stems. This not only prevents the hatching of eggs but also makes the leaves less enticing to tomato hornworms.
Neem oil also suffocates any pests on the leaves, thereby killing them.
Neem oil sprays are simple to use and much simpler to produce. In a water spray bottle, combine one tablespoon of neem oil and two cups of water.
You can spray your tomato plants as needed to keep tomato hornworms at bay. Remember to look for eggs on the undersides of leaves.
Cayenne Pepper Spray
Instead of using pesticides, make a natural garden spray out of cayenne pepper, water, and soap. Then, immediately spray it on your tomato plants.
The capsaicin in cayenne peppers drives hornworms away, making them easier to detect on the ground. It might potentially kill them. For this DIY garden spray to function, you must spray your plants on a frequent basis.
Cayenne pepper spray, as one might think, can be exceedingly irritating to the eyes, skin, and lungs. When working with it, use protective eyewear and clothes, and avoid spraying towards the wind.
Powder-based sprays may clog your spray bottle; either rinse off the nozzle often or switch to a non-powder variant.
Botanical Bt
If you have a really severe tomato hornworm infestation, you may need to use stronger management measures. Fortunately, you won’t have to resort to dangerous chemicals.
Botanical Bt (Bacillus thuringiensis) is one of the most effective natural insecticides against major tomato hornworm infestations.
Bt is a naturally occurring bacterium that is commonly found in soil. Bt, like neem oil, covers the leaves of tomato plants. When tomato hornworms consume it, it paralyzes their digestive processes.
They quit eating your plants and finally die. It is not as harmful to some beneficial insects, such as bees, as neem oil.
Introduce Beneficial Insects
Beneficial insects prevent and reduce hornworm infestations. Ladybugs and lacewings are the most effective to release. These predators are sold in online nurseries and garden stores because they devour eggs and other pests in your garden.
The paper wasp is another efficient natural killer of tomato hornworms. It feeds on a variety of caterpillars, so releasing paper wasps is a good option if you’re not sure whether it’s the tomato hornworm.
Plant Basil
When planted nearby, the chemical elements of the common garden herb basil are supposed to deter tomato hornworms while also improving tomato flavor.
Basil leaves have a strong odor that repels or inhibits flies and mosquitoes, which is another reason to spread this herb widely around the garden.
Marigold is another plant that may be used to deter tomato hornworms.
They emit a strong order that confuses, inhibits, or repels hazardous insects, such as the sphinx moth, which transforms into the tomato hornworm. Both Mexican and French marigolds have a distinct aroma that is connected with insect repellency.
How To Prevent Tomato Hornworms
Getting rid of tomato hornworms is one thing, but preventing them is much easier as it will save you the headache down the line when you start to see bitemarks in your plants.
Rotate The Crops
Crop rotation is an important gardening job that can save your tomato plants. If you’ve previously fought tomato hornworms, it’s advisable to modify where you grow your tomatoes next season.
The new location is unlikely to have any overwintering tomato hornworm pupae.
Crop rotation, in addition to avoiding tomato hornworm infestations, helps to reduce the spread of overwintering illnesses and other pests. It also offers your soil a rest between seasons, which is a huge benefit.
Row Covers
Floating row coverings are nothing new to seasoned tomato producers. These useful tools are inexpensive and widely available. They are, however, quite simple to build for the DIYers out there. You only need some shade cloth and PVC plumbing.
Row coverings are an excellent deterrent to tomato hornworms. They especially prevent hummingbird moths from landing on your tomato plants and laying eggs.
These necessary instruments will protect practically all of your plants from pests and diseases. They also protect your plants from the harsh elements of their surroundings, such as the sun’s rays and heat, as well as the biting cold.
Plastic Or Cardboard Covers
Another method for preventing hornworms in the garden is to cover your garden with black plastic when spring comes to prevent the moths from emerging. You’ve broken their lifecycle, and they’ll die before they can lay fresh eggs on the plants.
If you don’t want to use black plastic, you can use a thick sheet of cardboard instead.
Mulching
Another simple and multi-beneficial technique to keep tomato hornworms at bay is to mulch around the base of your tomato plants. It keeps freshly hatched hummingbird moths from digging into the soil and depositing eggs on your tomato plants.
While there are numerous mulching products available, black plastic mulch is ideal for combating tomato hornworms. It acts as a solid barrier, keeping the moths away from the surface and eventually causing them to die out beneath the soil.
Mulching provides a number of additional advantages. It keeps weeds at bay, as well as a variety of other overwintering insects and illnesses. It also stops water from pouring onto the leaves of tomato plants, preventing hazardous fungal infections from taking root.
Summary
We can all agree that tomato hornworms are one of the most annoying insects that you can find in your garden.
If you are growing plants such as tomatoes, potatoes, and peppers and you live in a temperate climate then you are very likely to have to deal with these pests at some point or another.
Luckily, now that you know what they look like, how to find them, how to get rid of them, and how to prevent them.
Don’t let their big horns scare you away though because they are totally harmless to humans so getting stuck in is the best thing to do before they eat everything that you have spent a lot of care with growing!
Hi, my name is Angie Strousse and I am a gardening enthusiast. Ever since I was a young girl, my favorite time of year was when I was able to get out in the yard and watch my dad begin his yearly gardening.
Growing up, we had a massive yard full of trees, shrubs, and plants. We would all bundle in the car and head down to the gardening center, where my brothers and I were able to pick one pack of seeds each to grow that year.
