13 Natural Ways to Get Rid of Armyworms on Plants

The name is given quite appropriately here. If you see an armyworm, there may be hundreds more to follow.

This is not ideal news, as armyworms can cause extensive crop damage [1]. If you have never seen an armyworm before, we will show you precisely what to look for and how to get rid of them if you find an infestation.

So, let’s assume that you have discovered armyworms in your garden. Now what?

How do you repel or kill them without damaging your plants or the beneficial insects you want to keep around?

Here’s how to get rid of armyworms naturally:

1. Manually Remove Them

This method is one of the best organic options for removing these caterpillars from your garden.

Go through your garden and remove the armyworm eggs and the armyworms by hand whenever you find them. Squish or drop them in hot, soapy water.

2. Spinosad

Spinosad is one of the best insecticides for armyworms and other types of destructive pests in your garden.

It kills armyworms and other soft-bodied pests naturally. This liquid insecticide is also safe for use on organic crops.

3. Parasitic Wasps

You can also introduce parasitic wasps into your garden. There are a few species you can choose from, such as braconid wasps and Trichogramma wasps.

These wasps will attack armyworms and other caterpillars and destroy them.

3. Neem Oil

You can also use neem oil to help control armyworms. Many organic gardeners use it as a common pest control treatment.

Neem oil is entirely natural and safe for external use on crops. You can also use this organic pesticide on houseplants. It both deters and kills an immense variety of insect pests.

To make a killer homemade armyworm spray, combine two tablespoons of neem oil and two teaspoons of liquid soap with a gallon of water.

Next, pour the mixture into a spray container and spray your plants. The liquid soap will help the solution stick to the plants longer.

Alternatively, buy a product containing neem oil and apply it according to the instructions on the container. This home remedy is safe for dogs, cats, and pets when used correctly.

4. Bacillus thuringiensis (Bt)

Bt will kill certain pests, such as small armyworm larvae, other leaf-eating caterpillars, and needle-eating caterpillars.

To control armyworms with BT, use it according to the instructions on the product label.

5. Regularly Check for Eggs

Perform regular checkups on your garden, and especially look for moth eggs. They are small and usually appear in clusters or rows on the leaves.

When you spot them, slide the eggs off the leaves and crush them between your fingers.

6. Soap and Water

Combine one ounce of Dawn dish soap with a gallon of water. If you do not use that brand, any liquid soap will do.

Shake well and apply the soapy water solution to your lawn to stimulate lawn armyworms’ movement to the surface. This way, natural predators like birds can catch and eat them.

Another method is to suffocate the armyworms. As you pick them off your plants, carry a bucket full of hot, soapy water. Pick them off and drop them into the bucket to suffocate and kill them.

7. Turn the Soil

As you near the end of the gardening season, be prepared to till and turn up the soil to expose any larvae and/or eggs that might be hiding.

This method will reveal them to hungry predators in the area.

8. Birds

Set out little dishes or birdbaths filled with water. Doing this may invite birds in, and they will notice the little destructive pests crawling around your yard.

Some plants may also attract birds. These include coneflowers, ivy, sunflowers, and honeysuckles.

Most birds choose caterpillars over crops any day, so do all you can to invite them in. Robins and starlings eat armyworms, and other birds might too.

9. Garlic and Pepper Spray

You can make a homemade repellent spray that works wonders against armyworms using spices such as garlic and hot peppers in water.

Blend four cloves of garlic and two hot peppers in two cups of water. Let the mixture steep overnight.

Afterward, strain and spray the solution on the caterpillars. This DIY armyworm insecticide will kill the pests.

10. Beneficial Nematodes

Beneficial nematodes can also help keep fall armyworms away. They will feed on armyworm larvae and armyworm eggs.

They will also help prevent other soil-dwelling pests from taking over.

11. Beneficial Insects

These insects could be one of your better options for getting rid of armyworms. You’re saving yourself a lot of trouble by luring in or releasing insects that eat other soft-bodied insects and related pests.

Parasitic wasps, ground beetles, and earwigs are great natural predators of armyworms. Additionally, minute pirate bugs, ladybugs, and lacewings feed on armyworm eggs.

12. Wood Ash and Chili Powder

Some African farmers have succeeded in using chili powder to control armyworms in maize. The recipe is five teaspoons of chili powder mixed with 2 kg of wood ash.

After combining correctly, they then shake the mixture into leaf whorls. This remedy burns and kills armyworms.

13. Vinegar

Some gardeners have also had success using vinegar to kill caterpillar pests. Mix two tablespoons of white vinegar with four liters of water and spray it directly on armyworms.

Types of Armyworms

There are several kinds of armyworms, and scientists estimate that well over half of them are destructive to many garden crops. With so many different species, it’s important to tell them apart.

1. Beet (Spodoptera exigua)

Image via Michasia Dowdy, University of Georgia, Bugwood.org

The beet armyworm is native to Southeast Asia but is also found in other parts of the world, including North America and Jamaica.

The older caterpillars are green to black, with dark green pigmentation running along their sides. The beet armyworm is also known as the asparagus fern caterpillar.

They will feed on scallions, alfalfa, citrus, grasses, corn, ferns, and ornamental plants. These pests also feed on cabbage, legumes, tomato plants, pepper plants, peas, potatoes, sugar beets, soybeans, sunflowers, other vegetables, and weeds.

2. Western Yellow Striped (Spodoptera praefica)

Image via cbc.ca

The Western Yellow Striped Armyworm, which, just as the name implies, is dark in color with two narrow yellow stripes.

It is commonly found in Columbia, Utah, and California.

They feed on tomato plants, rice, corn, potatoes, pepper fruits, sugar beets, alfalfa, and sweet potatoes.

3. Yellow-striped (Spodoptera ornithogalli)

Photo by Scott Housten – Flickr

This armyworm can be found throughout the northeastern regions of the U.S. and Canada. However, it has also been spotted out west, so be vigilant.

It has a much darker body color than Spodoptera praefica, and its markings are also sharper.

Spodoptera ornithogalli commonly feeds on soybeans, tobacco, corn, tomatoes, cotton, and alfalfa.

4. Common (Mythimna unipuncta)

Image via pyrgus.de

These armyworms are grayish-brown or grayish-green in color, with four large dark spots on the underside of their bodies.

They are a major threat in North, South, and Central America. They are common in Western Asia, Southern Europe, and Central Africa.

The common or true armyworm generally feeds on grass, oats, barley, wheat, and other seed crops.

5. Southern (Spodoptera eridania)

Image via alchetron.com

This armyworm is dark green with a brownish head and usually prominent yellow or white stripes. It is commonly found closer to the southern border, with occasional pop-ups further north and east.

You’ll likely find these armyworms on tomato plants. Other plants often affected are cassava, capsicum, cotton, sweet potatoes, legumes, maize, and tobacco.

6. African (Spodoptera exempta)

Picture via downtoearth.org.in

African armyworms, with mottled bodies in shades of green and brown, are a major threat to crops in Africa and Europe.

They mostly target corn but also eat other crops, such as rice, sugarcane, wheat, vegetables, sorghum, millet, and coconut.

7. Fall (Spodoptera frugiperda)

Photo via plantix.net

The fall armyworm has a dark head and varies in color from light tan to black.

Infestation is a significant threat in Myanmar, Bangladesh, China, Jamaica, Thailand, Indonesia, Sri Lanka, Laos, Vietnam, Malaysia, Egypt, Japan, and Korea.

The affected plants include maize, cotton, and vegetables. Also, rice, millet, sorghum, and hayfields. Plus, sugarcane and some fruit trees. They’ll also invade pastures.

8. Northern (Mythimna separata)

These armyworms are similar to common armyworms, which have nearly identical markings. However, they differ, with their stripes becoming more pronounced as they age.