Be on the lookout for fall armyworms

Published 3:09 pm Friday, August 10, 2018

This is the time of the year to keep a lookout for fall armyworms. This chronic moth flies up from south Florida and central and South America on air currents. 

It loves lush, well fertilized Bermudagrass and more than 60 summer and winter annuals. 

This ash gray moth with a wing span of 1.5 inches lays several hundred eggs on light colored surfaces such as fence rails, tree trunks and the underside of limbs. The egg masses darken with age and hatch within two to four days. They hatch all about the same time. 

Spinning silk threads, they descend to the ground. Their color varies from light green to black with several stripes along the body. A light colored inverted Y characterizes their face. On the next to the last segment are four dots arranged in a square. 

They start out small and go largely unnoticed. As they consume more forage they increase in size and suddenly their feeding damage is apparent and they seem to be everywhere, hence the moniker “armyworms.” 

If you don’t treat, they will pupate in about two to three weeks and burrow into the soil. Moths will emerge in about two weeks and the cycle will begin again. 

Fields treated for fall armyworms should be checked in about two weeks to determine whether to re-treat those fields. Three caterpillars per square foot or caterpillars or half inch long or longer is the threshold for control.

A sign of fall armyworms are flocks of birds such as crows, geese and turkeys going to town with their heads down in the grass. Go over and investigate why they’re giving so much attention to that pasture. 

Scouting the fields is very important in early detection. The smaller the caterpillar, the easier it is to control. If the use of pesticides is not an option, mowing may be the best option for salvaging a hay crop.

Fall armyworms rarely kill established bermudagrass but the defoliation weakens the plants. The spots look like they’re burned or browned out. 

Livestock is deprived of grazing and hay cut for winter storage will not be available. This all diminishes the profit margins of livestock producers. 

Controlling army worms with insecticides needs careful consideration. Some insecticides such as Sevin XLR Plus need a 14-day withdrawal period before grazing and the minimum retreatment is 14 days. You are allowed two to three applications per cutting of hay. Read the label very carefully. Call the extension office if you have any questions.

What’s going on in Extension?

4Beekeepers Meeting: Monday, Aug. 20 at the Extension Office at 7 p.m.

4TCCA Meeting: Tuesday, Aug. 21. Topic: Improving Forages. Dinner begins at 7 p.m. Dinner is at 7 p.m., cost $6. Call ahead and the program begins at 7:30 p.m. at the Ag Center.

4Market on Main: Every Saturday morning from 8 a.m. to 10 a.m. just off the square. Come by and enjoy the pick of the day. 

If you have any questions or concerns, stop by or call the office. 

The Troup County Extension office is located at 144 Sam Walker Drive, LaGrange, GA. 30240 (706) 883-1675. It’s open Monday through Friday from 8 a.m. to noon and from 1 p.m. to  5 p.m. Email: