The name is given quite aptly here. If you see an armyworm, then there may be hundreds more to follow.
This is not exactly ideal news, as they can cause extensive crop damage [1]. If you’ve never seen an army worm before, we’ll show you precisely what to look for as well as how to kill them if you do find that you’ve got an infestation.
So let’s assume that you’ve discovered leaf-eating worms that look like voracious caterpillars in your precious garden. Now what?
How do you repel army worms effectively without damaging your plants or the beneficial insects you want to keep around?
Here’s how to get rid of armyworms organically and naturally:
1. Manually Remove Them
This is one of the best organic options for guaranteed removal and death of these worms.
Physically go through your garden and remove them by hand as you find them. Squish or drop them in hot, soapy water.
2. Spinosad
One of the best insecticides for armyworms and other types of destructive pests in your garden is Spinosad.
Made by a soil bacterium, Spinosad kills army worms and other soft-bodied pests naturally. This liquid insecticide is also safe to use on organic crops.
3. Predatory Wasps
You can always introduce predatory wasps into your garden. There are a few varieties you can choose from, such as braconid wasps, Ichneumon wasps, and Trichogramma wasps.
The second option thrives side-by-side with the critters, with the wasps laying their eggs inside armyworm eggs. The wasp larvae will consume the army caterpillar before it has a chance to hatch.
3. Neem Oil
You can use neem oil for armyworms, as it is a classic pest control treatment used by organic gardeners everywhere.
Neem oil is entirely natural and utterly safe for external use on crops. You can also use this organic pesticide in your house. It both deters and kills an immense variety of intrusive insects.
To make a killer homemade army worm spray, combine 2 tablespoons of neem oil and 2 teaspoons of liquid soap with a gallon of water.
Next, pour the mixture into a spray container and coat your plants. The liquid soap will make the solution stick to the plant for longer.
Alternatively, buy the concentrate and apply it according to the instructions on the container.
When used correctly, this home remedy is also safe to use around dogs, cats, and pets in general.
4. Bacillus thuringiensis (Bt)
Bt is a natural bacteria that will kill certain pests, such as small armyworm larvae, leaf-eating caterpillars, and needle-eating caterpillars.
To control armyworms, use it according to the instructions that come with your purchase. Reapply after heavy rains.
5. Regularly Check for Eggs
Perform regular checkups on your garden, and especially keep an eye out for moth eggs. They’ll look like cottony little clumps on the underside of leaves.
As you spot them, slide the eggs off the leaves and crush them between your fingers.
Moreover, this is by far the most effective method for small farmers to get rid of armyworms on tomatoes, Brussels sprouts, and other crops, as it prevents them from hatching in the first place.
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 their movement to the surface so natural predators like birds can catch and eat them.
Another method is to suffocate them. As you go around picking off the armyworms, 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 any soil you have left to expose whatever pupae might still be hiding.
This will reveal the critters to hungry predators in the area, preventing further headaches for you next season.
8. Set up Bird Baths
Set out little dishes or birdbaths filled with water. This will invite birds in, and they’ll notice the little destructive pests you’ve got crawling around your yard.
Most birds will choose caterpillars over crops any day, so do all you can to invite them in. Robins and starlings eat armyworms, and others might too.
9. Garlic and Pepper Spray
Using such spices as garlic and hot peppers in water, you can make a homemade repellent spray that works wonders against army worms.
Blend 4 cloves of garlic and 2 hot peppers in two cups of water. Let the mixture steep overnight.
Next, strain and spray the solution on the little annoying critters. This DIY armyworm insecticide will kill them.
10. Beneficial Nematodes
These naturally occurring enemies may be weird to think about introducing, but trust us, they will keep army worms away.
Beneficial nematodes will zone in on armyworm larvae and subdue and eliminate the threat.
Plus, they’ll stick around to help prevent other soil-dwelling pests from staking a claim, so it’s a potentially worthy investment.
11. Bird-Attracting Plants
Plants that attract birds include coneflowers, ivy, sunflowers, and honeysuckle. These will encourage birds to come around and devour the army caterpillars they find.
Birds work fast and eat faster. Plus, as they’re digging down to get their food, they disrupt the soil, upsetting any eggs that might be hiding and helping the process along even faster.
12. Beneficial Insects
This could be one of your better options for getting rid of armyworms. By luring in or releasing insects that eat other soft-bodied insects and related pests, you’re saving yourself a lot of trouble.
Along with parasitic wasps, ground beetles and earwigs are also great natural predators. Additionally, minute pirate bugs, ladybugs, and lacewings feed on armyworm eggs.
13. Wood Ash and Chili Powder
To help control armyworms in maize, some African farmers have had success mixing 5 teaspoons of chili powder with a 2kg container of wood ash.
After combining properly, they then shake the mixture into leaf whorls. This remedy burns and kills the critters.
What are Armyworms?
Now that you know how to get rid of armyworms naturally, let’s learn a bit more about them.
From the Noctuidae family, they are tiny, grub-like creatures that invade gardens and like to hang out on the undersides of leaves during the day.
At night, they come out to munch on your plants in relative safety.
They’re generously distributed across the United States, especially east of the Rocky Mountains, with an expansive schedule of activity throughout the year [2].
These annoying, soft-bodied little creatures are found on every single continent except Antarctica, much to the dismay of farmers everywhere.
Considered a major threat in some countries and virtually unstoppable by passive means. This is one pest that farmers everywhere absolutely must take seriously if they wish to protect their produce.
What Does an Army Worm Look Like?
They come in a wide variety of colors: light tan, muddy, greenish-brown, blackish, etc. You will find pictures of armyworms further in this article.
Signs of Damage
Leaves will be chewed up, and if you’re growing soft-skinned fruits and vegetables, you might find minute little holes burrowed into them.
The problem is that these leaf-eating worms sometimes burrow into crops to further develop, which is revolting on its own.
Some also produce a type of cottony substance on the undersides of leaves, further hinting that they’ve been there.
Types of Armyworms
There are several kinds of army worms, and scientists estimate that well over half of them are severely destructive to all crops in general.
And with so many different species, it’s important to tell them apart from one another.
1. Beet (Spodoptera exigua)
Image via Michasia Dowdy, University of Georgia, Bugwood.org
Green and smooth in coloration, with dark green pigmentation running along its top and sides. It is also known as the asparagus fern caterpillar.
The beet armyworm is native to Southeast Asia but is found in other parts of the world, in countries like North America and Jamaica.
It is one of the most dangerous kinds, and they mostly feed on scallion (green onion), alfalfa, citrus, grasses, corn, ferns, and ornamental plants.
Like the cabbage looper, they also feed on cabbage, legumes, tomato plants, pepper, pea, potato, 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 lines.
It is commonly found in Columbia, Utah, and California.
They generally 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 one can be found all around the northeastern regions of the US and Canada. However, they have been spotted out west as well, 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
They are grayish-brown or grayish-green in color, with four large dark spots on the underside of their bodies.
They are a significant menace throughout North, South, and Central America and are also 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
Dark green with a brownish head and normally prominent yellow or white stripes. Commonly found closer to the southern border, with occasional pop-ups further north and east.
You’ll likely find these pests on tomato plants. Other plants commonly affected are cassava, capsicum, cotton, sweet potatoes, legumes, maize, and tobacco.
6. African (Spodoptera exempta)
Picture via downtoearth.org.in
Featuring a mottled body with varying shades of green and brown, it is a major threat to crops in both Africa and Europe.
The species mostly targets corn. However, they 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 major threat in countries like Myanmar, Bangladesh, China, Jamaica, Thailand, Indonesia, Sri Lanka, Laos, Vietnam, Malaysia, Egypt, Japan, and Korea.
Some of the plants affected include maize, cotton, vegetables, rice, millet, sorghum, hayfields, sugarcane, and the fruits of some trees. They’ll also invade pastures.
8. Northern (Mythimna separata)
Similar to the common armyworm, which has nearly identical markings, these differ, with their stripes becoming more pronounced as they age.
They mainly eat corn, sorghum, barley, rice, and wheat.
9. Lawn (Spodoptera mauritia)
Image via lawngreen.com.au
Common throughout India, Australia, the Malayan Peninsula, and the Pacific Islands, the lawn armyworm starts off with a pale green color.
It then develops a dark green back with white and brown stripes at its sides.
This type mainly feeds on lawn grasses, oats, and barley.
Life Cycle
Eggs are laid in clusters in protected spots that the larvae can consume once they hatch, usually grass or leaf blades.
Once hatched, the larvae become a force of nature, becoming extremely destructive and often moving in large groups in search of food.
They grow up to about 30mm in length, and after about 14 to 20 days, they spend 11 to 13 days pupating in the soil.
They then emerge as fully grown moths with a lifespan of about two weeks total, ready to lay over 1,000 eggs and begin the destructive process all over again.
Impact on Crops
Because they tend to move in large groups, heavy infestations can destroy crops in very little time.
Different worms feed on different things, but to narrow it down, there isn’t any crop that’s safe from these worms.
Even grass isn’t safe, as the lawn army worm pretty much exists to mow it down. So pay close attention to the types of crops you’re growing and at what times of the year.
This way, you can be best prepared for the possibility of them showing up in your gardens.
See also: 13 Natural Ways to Get Rid of Cabbage Worms
Takeaway
The key to stopping an armyworm infestation is to be extremely vigilant about your garden and spot the minuscule signs before they become a problem that will be too big to deal with.
Once you’ve spotted the critters, pick an army worm treatment or home remedy from the list above to get rid of them.
Very educative