How to Get Rid of Army Worms: Life Cycle, Harm, and Control - Backyard Boss
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How to Get Rid of Army Worms: Life Cycle, Harm, and Control

If you’ve ever watched your entire lawn get demolished by armyworms, patch by patch, then you’ll know why these pests get their name. They attack without notice from one area to the next and damage plants very quickly.

Armyworms feed primarily on fescue, bermudagrass, and ryegrass and eat vegetables such as onions, beans, pepper, and cabbage. They can rapidly cause significant damage to your lawn or crops if not treated quickly.

Get rid of these destructive pests before they destroy your entire yard. This guide will reveal how to identify armyworms and how to get rid of them effectively.

What Do Army Worms Look Like?

More commonly found in the southeastern United States, the armyworm is the larvae of a small moth with white hind wings. They’re not really worms but are the caterpillars of the moth Spodoptera Mauritia, a prolific breeder that can produce up to 300 eggs in a single laying.

These caterpillars are light green in their early growth stage and become a darker green or brown in their later stages. Fully-grown armyworms are one to two inches long and can easily be identified by their series of green, brown, or yellow stripes on their bodies.

Army Worm Life Cycle

The armyworm life cycle has four basic life stages: egg, larva, pupa, and adult.

Egg Stage

The female moth will lay 200 to 300 eggs in a single laying, then do the same thing the following night and the next. One female moth can lay up to 1,000 eggs, finding suitable spots to lay her eggs on the undersides of tree leaves or structures. These structures can include cabins, water coolers, light posts, and more.

Larva Stage

After about a week, the eggs hatch, and the newly formed larvae (caterpillars) emerge with the sole objective being to eat as much grass or leaves as possible. This goes on within the next 20 to 35 days before they move onto their pupae stage. They feed throughout the day but are most active in the early morning and late evening hours.

Pupa Stage

The development from eggs to full-grown larvae usually takes anywhere between two to three weeks, at which point the larvae will bury themselves deep into the soil to pupate and emerge as adults. After this 10-14 day period, the life cycle begins again.

Adult Stage

Adult moths are generally gray, with white underwings. Their forewings are usually mottled with white dots, while male moths typically have a triangular white spot near their wingtips.

How to Tell If Your Yard Has Army Worms

Armyworms are difficult to find, as they spend most of their days hiding in soil or deep inside lawn. They come out at dusk and spend the entire night feeding on your lawn or crops. However, there are a few simple hacks you can follow to identify these pests.

1. Dish Soap and Water

The first method involves using water mixed with dishwashing liquid. You mix a fair amount of dishwashing liquid in a bucket full of water. You then pour the mixture over the lawn area and monitor it for a few minutes. After 10 minutes or so, you can check for caterpillars rising to the surface.

2. Find Them at Night

The second method involves going out onto your yard at night with a torchlight and catching them in the act. With your torch in hand, get down low onto the lawn and carefully run the light over it, looking for caterpillars feeding or moving.

3. Check for Moths at Night

The last method is to use a simple light source. To check for moths in your garden area, leave a bright light source in your lawn area at night. After a few hours, go outside to check the light. If you find moths flying around it, this may be a sign of a possible armyworm problem, requiring further investigation.

If you do find caterpillars with any of these methods, then it’s best to capture a few to take to the local nursery to get them checked for identification. Doing this will help you get the best recommendation for a suitable insecticide for your pest problem.

What Kills Army Worms?

Armyworms generally feed around the clock, but their most active times are early morning and late evening. Once you’ve identified armyworms, you can treat them with insecticides or organic chemicals, readily available for purchase from online garden stores and nurseries.

The insecticide mixture should be applied to the lawn just before dusk, just before the armyworms start feeding. Bacillus thuringiensis and spinosad applications will often control armyworms and other caterpillar pests.

If you’re on a tight budget, then simple dishwashing soap will do the trick.

Does Dawn Dish Soap Kill Army Worms?

One may also ask, does Dawn dishwashing soap kill armyworms? The simple answer is yes. It doesn’t take much; just a teaspoonful for a gallon of water will do the trick. You can apply a gallon of this mixture to four square feet of lawn and watch it work its magic.

How You Can Stop Them

If left untreated, armyworms can quickly devour through your lawn. Eventually, patches of your lawn may die, so it’s important to restore growth as soon as possible.

You can easily treat them with insecticides or organic materials readily available for purchase from online garden stores or nurseries. To encourage your lawn’s growth again, you can add lawn fertilizer and several deep waterings a week.