How To Get Rid Of Armyworms

Armyworms are given their name for a good reason! When they invade your garden, they can destroy everything in their path, and stopping them can be difficult. The good news is that there are things you can do to help prevent the attack before it starts, or control the onslaught once it hits. In this article, we’ll be going over how to get rid of armyworms in your garden!

What are Armyworms?

Although these pests are referred to as armyworms, they are actually from the moth family. There are many different types of armyworms, but they all have a similar lifecycle. 

The moths, which are generally light brown, can produce 100s of eggs every night, and they can repeat this process for several nights in a row. The eggs are usually laid in large clusters on the underneath side of leaves. 

Female moths can produce up to 2,000 eggs, which is not good news for your lawn, especially as there is likely to be more than one moth living in your garden! 

After around a week, caterpillars (armyworm larvae) hatch from the eggs, and for the next few weeks, they are looking for as much green grass, shrubs, fruit, and other vegetation to eat as they can find. The caterpillars start as a light green color, but as they mature, they turn a darker green, almost black. When they are fully grown, they’re about 1½ inches in length and often have a distinctive stripe down their back and sides. 

Once these caterpillars have done their damage, they will burrow into the ground before pupating. After a week or so, they emerge as moths, and the whole cycle begins again. Several generations are produced each season.

How to Prevent Armyworms

Before we look at how to get rid of armyworms, let’s look at ways you can prevent them from invading your vegetation in the first place.

Weeds can be attractive places for moths to lay eggs, so keeping your weeds under control can be a good preventative measure. Mowing your lawn or field regularly is also a good idea. Once you’ve mowed it, if you then water it, this will encourage any caterpillars to move on.

Armyworms can also be taken care of by natural predators such as birds, rodents, beneficial insects, and other larvae predators. Some varieties of flies and wasps and other parasites can be effective in keeping them under control. 

You may want to plant specific things to attract birds and other insects, and by avoiding using any harmful pesticides in your garden, you can make sure any beneficial insects you already have to stay alive.  

Caterpillars love to hide in the thatch that gathers around the base of your grass plants, so to prevent this from happening, you should dethatch your lawn frequently and never allow a layer more than ½ inch thick to develop.

The Early Signs of Armyworms

The earlier you start dealing with your armyworm problem, the easier it will be to control, so it is good to look out for early signs.

Because armyworms are most active during the night and hide under the grass or other plants during the day, they can be challenging to spot, and they can do a lot of damage before you even know they are there. 

A few things to look out for include brown spots on your lawn, an increased number of birds in the area or armyworm droppings (which look a bit like black pepper).

The caterpillars themselves are not always obvious, check the underside of the leaves. If you find any, pick them off with your fingers and drop them in a bucket of soapy water. Although they should die almost immediately, it is a good idea to leave them in there for an hour or so to be sure.

As moths are attracted to light, if you go out into your yard with a torch when it’s dark, you should be able to spot them. And if you don’t fancy being outside late at night, if you mix some water and detergent in a bucket and pour this over a patch of grass, this will wake up the caterpillars, and they should surface after about 10 minutes.

How to Control Armyworms Naturally

One of the many problems with using harmful pesticides is that you could inadvertently be destroying armyworm predators. Luckily, there are some natural alternatives.

One option is beneficial nematodes. These are microscopic soil creatures that will eat the eggs, pupae, and larvae of hundreds of pests including armyworms. And the good thing about releasing nematodes into your soil is that they don’t harm plants, earthworms, honey bees, or beneficial insects.

Another method is to release Trichogramma wasps into your garden. You can buy these in garden supply stores or online. These tiny parasites attack the eggs of 100s of species of moths and caterpillars by laying their eggs inside the eggs of the moth, preventing them from hatching. This can break the lifecycle of the armyworms.

Once you see signs of moths, you can set pheromone traps to catch them. These traps use visual cues, such as colors and shapes, to attract insects rather than pesticides.

Another tip is to overturn your soil at the end of the day, which will bring any larvae to the surface. You can then remove them by hand or let birds eat them! Another way to bring them to the surface is to place a wet blanket on your lawn in the evening. This will bring the armyworms to the surface

Over the years, many natural solutions for controlling these pests have been tried with some success. Examples are garlic sprays, pyrethrum sprays, oil sprays, and even bug juice. So there are many ideas to experiment with.

Are Chemicals an Option for Treating Armyworms?

 Although low-level infestation should be able to be treated without pesticides, it may be necessary to use insecticides such as chlorpyriphos if the problem is widespread. 

Use them with caution and under advice, and be aware that they can negatively impact other animals. And if you do use an insecticide to kill the armyworm larvae, make sure you then add nutrients that are high in nitrogen to your lawn to stimulate regrowth. Water your lawn extensively. 

Final Thoughts

Armyworms can cause a lot of damage to your garden if you don’t do anything about them. But if you know what to look out for, there are many ways you can reduce the likelihood of them taking up residence in your yard. If they do, though, there are several strategies you can use to deal with your armyworm infestation and hopefully make them go away!