Fall Armyworms

Craig Roussel  |  9/14/2012 2:28:48 AM

Fall armyworm larva.

Adult moth responsible for the armyworm.

Heavy infestations of armyworms have been reported in the area. We are getting calls and emails from homeowners about thousands of worms eating their lawns.

The adult moth responsible for the armyworm is brown in color with a wingspan of 1 ½ inches wide. They lay eggs on the leaves of the turfgrass and the eggs may hatch in as little as 2 days. The larvae can feed for 2 to 3 weeks causing severe turfgrass damage. Eventually, the larvae burrow into the soil and pupate transforming into the adult moth. This process takes approximately 2 weeks. There may be up to three or four generations each fall.

Fall armyworm larvae can grow up to 1½ inches long, and have 2 black stripes their entire body length. Their color ranges from black to green. However, the most distinguishing characteristic is the inverted Y on its head.

Armyworms have chewing mouth parts that completely devour the leaves, rendering large areas void of foliage. They usually attack with very heavy populations, and from a distance their damage resembles a drought. They are generally active at mid-day, making them fairly easy to find. Homeowners may also notice birds feeding in the lawn which can be an indication of an infestation.

Fall armyworms can be controlled with bifenthrin (Talstar, Bug B Gon Max, etc.) or carbaryl (Sevin, Carbaryl, etc.). Follow label directions for amounts and method of application.

Rate This Article:

Have a question or comment about the information on this page?

Innovate . Educate . Improve Lives

The LSU AgCenter and the LSU College of Agriculture

Top