Controlling Fall Armyworms

For the past few days we have been getting numerous phone calls about tan to light grey moths less than an inch long flying around shrubs, trees, and lawns. All of the moths I’ve collected or have brought to the plant diagnostic lab have been fall armyworm moths. The moths are the direct result of the outbreak of fall armyworms that has occurred in the last 2-3 weeks. The adult moths live about 10 days.

Fall armyworm moths brought to the Extension lab this week.

Fall armyworm moths brought to the Extension lab this week.

Fall armyworms are insect pest of lawn grasses, especially bermudagrass, and seem to be worse than normal this year. Armyworm damage have been a common sight in many local neighborhoods in the last few weeks.

Bermudagrass lawn after fall armyworms have eaten nearly all the leaves, leaving a brown lawn.

Bermudagrass lawn after fall armyworms have eaten nearly all the leaves, leaving a brown lawn.

The good news is that most established lawns damaged by armyworms will recover and won’t suffer any long term effects. The damage is generally aesthetic. However, newly installed sod can suffer longer-term damage and should be closely monitored. My own backyard was damaged by armyworms recently, but within a week it had largely recovered. Just remember to water the lawn if the soil is dry to speed the recovery.

We are still getting a few calls about new armyworm damage to lawns. So, keep any eye out for areas of the lawn that suddenly start to turn brown. Bird or wasp activity in the lawn can also be a sign of armyworms. An easy way to check and see if armyworms are in your lawn is to do a soapy water flush. This technique uses a mixture of water and liquid dishwashing detergent from your kitchen. Add about 2 tablespoons of detergent in 2 gallons of water and pour it slowly over about 1 square yard area. If you have armyworms they will pop to the surface within a few minutes. Once they are detected there are several insecticides that provide effective control. See the following link to a recently revised publication that provides a list of insecticides, plus other useful tips on controlling armyworms.  http://www.aces.edu/pubs/docs/A/ANR-0172/ANR-0172.pdf

Newly installed zoysiagrass lawn showing damage from fall armyworms last week.

Newly installed zoysiagrass lawn showing damage from fall armyworms last week.

Fall armyworm larvae collected from the zoysiagrass lawn pictures above using the soapy water flush technique.  Full grown larvae are between 1.25-1.5 inches long.

Fall armyworm larvae collected from the zoysiagrass lawn pictures above using the soapy water flush technique. Full grown larvae are between 1.25-1.5 inches long.

By Jim Jacobi, Extension Plant Pathology Specialist, Alabama Cooperative Extension System.  Contact Jim at jacobjc@auburn.edu.


The Alabama Cooperative Extension System (ACES) operates as the primary outreach organization for the land-grant functions of Alabama A&M and Auburn Universities. ACES is committed to affirmative action, equal opportunity and the diversity of its workforce.  Educational programs of ACES serve all people regardless of race, color, age, sex, religion, disability, sexual orientation, or national origin.

Alabama Extension

The Alabama Cooperative Extension System operates as the primary outreach organization for the land-grant functions of Alabama A&M and Auburn Universities and answers home-gardeners' questions each week on Birmingham Gardening Today.

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