What Do Army Worms Turn Into?

Do you have Army Worms in your garden? Here’s what you need to know about these pests, including what they turn into.

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Army worms are the caterpillar larva of several different species of moths. The adult moths are night flyers and are attracted to lights, which is why you may see them around your porch light in the summer. Army worms get their name from their habit of marching in large groups across open fields devouring everything in their path. Although they mostly eat grasses, they will also attack corn, wheat, and other crops. Fortunately, army worms don’t survive very long in cold weather and they are not a serious threat to crops in most parts of the country.

What are Army Worms?

Army worms are a type of caterpillar that can cause extensive damage to crops. The larvae are black or green and have striped markings on their bodies. Army worms get their name from their habit of moving in large groups and eating everything in their path.


Armyworms are the caterpillars of several different species of moths. The adult moths are brown or gray and have a wingspan of about 1 inch. The moths lay their eggs on the undersides of leaves, and the eggs hatch into armyworms.

Armyworms are green or brown with stripes running lengthwise down their bodies. They have large heads with chewing mouthparts, and they can grow to be about 2 inches long. Armyworms are pests of many different crops, including corn, wheat, and grasses. They feed on the leaves of plants, and can cause extensive damage in a short period of time.

When they are full-grown, armyworms pupate in the soil. After a few weeks, they emerge as adult moths and begin the cycle anew.


Armyworms are generalists and will eat just about any kind of vegetation they can find. However, their preferred diet is grass. Some of the plants that armyworms will eat include:

Life Cycle of Army Worms

Army worms go through four main stages in their life cycle- the egg, larva, pupa, and adult. The time it takes for them to complete their life cycle depends on the temperature and the availability of food. The warmer the temperature is, the faster they will develop. Keep reading to learn more about the life cycle of army worms!


Army worms go through four stages of life: egg, larva, pupa and adult. The time it takes to go through all four stages depends on the temperature. In warm weather, it can take as little as two weeks while in cooler weather it may take a month or longer.

Egg: Army worm eggs are usually laid in clusters of about 50 on the undersides of leaves. They are small, oval and Initially bright yellow, but turn brown just before hatching.

Larva: Larvae are the actively feeding stage of army worms. They are velvety green with a faint stripe running down each side of their bodies and have shiny black heads. Fullgrown larvae can be up to 1 1/2 inches long.

Pupa:: Pupae are inactive, non-feeding stage of army worms. They are dark brown and about the same size as adults.

Adult: Adult army worms are moths with a wingspan of about 1 1/2 inches. They are light gray with dark markings on their front wings and they have asnake-like head projection. Females lay their eggs on theundersides of leaves soon after they mate


As with most moths, the armyworm’s life begins as an egg. The female moth will lay her eggs in groups of up to 500 on the underside of leaves. Once the eggs hatch, the larvae (caterpillars) will begin to feed. The armyworm Caterpillar is a voracious eater and will consume enormous quantities of foliage during its time as a larva. Depending on the availability of food, armyworms can complete their growth in as little as three weeks.

As they approach maturity, armyworms will begin to congregate in large groups and migrate in search of food. This behavior often brings them into conflict with humans as they enter into agricultural areas and begin to devour crops.

Once they have reached full size, the caterpillars will burrow into the soil to pupate. The pupal stage lasts 10-14 days before the adult moth emerges.


After the caterpillar stage, armyworms enter the pupal stage. Pupae are non-feeding, quiescent stages in an insect’s lifecycle. They undergo metamorphosis, during which dramatic physical changes occur that transform them into adults.

Pupae of many kinds of Lepidoptera (butterflies and moths) are exarate, meaning that their legs and other appendages are not glued down by a waxy coating. They have a hard outer layer of skin called a puparium or chrysalis.

During the pupal stage, armyworms do not eat and they stop moving around. pupae can be found in a variety of locations depending on the species. Many spend this phase underground while others attach themselves to plant stems or leaves. Some even build cocoons out of silk and bits of plants or soil.


Once they have mating, the female moths lay their eggs on plants. The larvae hatch a few days later and immediately start to feed. Each larva can consume up to 85,000 seeds during its lifetime. When they are ready to pupate, the larvae burrow into the soil to transform into adults. The adult moths emerge a few weeks later to mate and begin the cycle anew.

Army Worms as Pests

Armyworms are the larvae of several types of moths. The name “armyworm” comes from their habit of migrating in large groups, or armies. These voracious feeders can strip a field of crops in a matter of days, causing extensive damage to farmers.

Armyworms are often difficult to control once they establish themselves in an area because they reproduce quickly and have few natural predators. Chemical pesticides are usually required to get rid of them.

Control and Prevention of Army Worms

Army Worms are the caterpillar larvae of a small owlet moth. The larvae are green with a dark stripe running down their back. These pests are known to be destructive to crops and gardens, and can quickly destroy a plant if left unchecked. If you think you may have army worms in your garden, it’s important to take action quickly to control and prevent them.

Cultural Control

Cultural control is the most important and effective means of managing armyworms. Practices that encourage a dense, competitive stand of grass crops are most effective. In small grains, this usually means seeding at the recommended rate for the area, providing adequate fertilizer, and maintaining proper soil pH. Mowing systems that keep the crop canopy open (such as rotary mowers) are helpful in reducing armyworm numbers and preventing economic losses. Regular scouting and early detection are also essential for effective cultural control of armyworms.

Biological Control

Biological control of armyworms is the use of predators, parasites and diseases to keep their populations in check. Ladybugs, green lacewings and parasitic wasps are some of the most commonly used beneficial insects for managing armyworms. These predators feed on both the caterpillars and eggs of armyworms, providing an effective means of population control.

Chemical Control

The recommended method of controlling armyworms is with chemical sprays. Apply the insecticide when caterpillars are young and still feeding on leaves. Be sure to follow all directions and safety precautions on the label. Usually, two applications are required for complete control. Apply the first application when caterpillars are small, and the second 7-10 days later.


At this point, you should have a good idea of what an Army worm is, what they eat, and how to get rid of them. You should also know that there are different types of Army worms, each of which has its own set of characteristics. If you think you have an Army worm problem, the best course of action is to call a pest control professional.

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