Armyworm Control: How to Identify, Prevent and Get Rid of Armyworms

Armyworms are disparaging pests that cause the death of plants within just a day. They are caterpillar pests that commonly thrive in cereal crops, especially corn. They exist in the form of small armies and they consume almost anything that they see along their way. These pests do not give mercy to any part of the plant, which makes it important to know how to get rid of armyworms.

There are three species of armyworms: Common Armyworm, Southern Armyworm, and Inland Armyworm. However, they are almost all the same in terms of their appearance and the infestations they bring. When they mature, they are color gray or brown, with a wingspan of 1.5 to 2 inches. There is a small white dot on the front of their wings. The length is usually two to 40mm. One of the most common characteristics of adult armyworms is the presence of three stripes at their back, usually cream or white.

Armyworm Digging Soil

Armyworm Digs into the Soil to Pupate

Armyworm’s Habitat

In the United States, armyworms are common in the Rocky Mountains and the extreme southwestern States. They are also common in the southern part of Canada. When it comes to crops, they survive in small grains, rice, corn, and legumes. They feed on gardens, golf courses, and agricultural lands. Once they finish feeding on a specific portion, they move on to their next target.

They usually appear during autumn and spring, specifically in the evening. They are active in environments that are humid.  They lay their eggs in batches of five to 30, and it takes only about 20 days before they hatch. If you live in a place with a warm climate, on the other hand, they are possibly active all throughout the year. Armyworms also usually grow in no-till fields.

Identifying Armyworm Damage

Plants Affected

Armyworms usually feed on the plants from the family of grass. However, because of hunger stress, they also find their way in other plants, such as legumes, lettuce, and cabbage. They will also be common in corns and grassy fields.


In most instances, it is too late before you realize that armyworms are present in the garden or field. By the time that you learn about the outcome, they have already moved to a different location. Generally, the following are some of the symptoms:

  • One of the most obvious is leaf scalloping. In layman’s term, this refers to a leaf that appears to have been chewed. The edges will turn rough and crooked.
  • There is also a possibility that a plant will suffer from severe defoliation. This is a condition that refers to the total removal of the leaves of the plant, retaining only its stalk.
  • Depending on the plant where they are present, they will eat the green areas. In cereals, they feed below the head of the seed. On the other hand, in wheat and barley, they severe the entire head.

Results of Infestation

In cases of serious damages, when it is too late to take action, armyworms can cause total destruction of grass and crops. You might end up waking to an empty lawn because of the damage from these pests. Your garden will most probably look unsightly. The bad news is that it can happen throughout the night. In fields for animal-raising, the pasture for feeding will significantly reduce in size because of the infestation. In commercial plantations, this can lead to financial losses as it makes the crop useless after infestation.

Leaf Damaged by Armyworm

Corn Leaf Damaged by Fall Armyworm

How to Get Rid of Armyworms

Organic and Natural Solutions

Controlling armyworms in a safe and natural manner is possible through the following:

  • Mowing the grass is one of the best ways to get rid of this pest. They crawl during the night and they will not stop until they have nowhere to feed on. Through mowing, you are removing them from the surface before they can spread greater damage to the healthier parts of the lawn.
  • Encouraging the presence of beneficial insects will work like magic. With this, avoid using pesticides with toxic ingredients as they kill not only armyworms, but even insects that prevent their presence. Among these insects, Trichogramma Wasps are indeed the most popular. It is great to have this parasite in the garden because it attacks not just armyworms, but more than 200 other types of caterpillars and moths.
  • Attracting birds to the garden will also be helpful. With the natural attraction of birds toward moths, they will pull the larvae from the surface where the armyworms are present.
  • You do not need to spend a lot to control the presence of armyworms, one cheap, but effective solution is the use of neem oil. Use it as a main ingredient for a homemade pesticide. When applying, cover the entire area of the plant to yield the highest level of effectiveness.
  • There are also certain organic products that deliver a high level of effectiveness, such as those that contain Bacillus Thuringiensis. It is a safe ingredient that kills pest without harming other animals around or the environment in general.

Chemical Solutions

The use of chemical control is common in large plantations with crops that are prone to armyworm damage. At home, however, stay away from this solution as this is toxic not only for the pest, but for the environment, and worst, even for our health.

Two of the most popular chemical solutions for armyworms are Alpha-cypermethrin and Chlorpyrifos. When spraying, proper mixture is necessary. Mix no more than 40 ml of the chemical with 20 liters of water spray it in the afternoon because the pests appear at night.

How to Prevent Armyworms

There are many ways to prevent the presence of this pest, but one of the easiest is to plant grass varieties that resist their presence. This helps to have a healthy turf. Choose a grass that contains endophytic fungi, which will get rid of armyworm. Some of the best varieties include Sunrise, Repell, and Commander.

In the agricultural sector, acting quickly will prevent damages from armyworms. This means that you should time your harvest perfectly. Do it before the season where armyworms appear. With this, they have nowhere to feed on because you are already done with the harvest.

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