Troup extension agent: Fall armyworms attacking

Published 12:00 am Friday, August 26, 2016

Armyworms have invaded Troup County in force.

We have had numerous calls and emails concerning fall armyworms. This chronic moth flies up from south Florida and Central America and South America on air currents. It loves lush, well-fertilized Bermudagrass and over 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 ½ 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 armyworms 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?

• Sept. 1: Planting Food Plots for Deer Wildlife Program. 6:30–8 p.m. at the Oakhurst Farm, just south of Jones Crossroads on Ga. Highway 219. Call to register, no cost. Wildlife specialist Mark McConnell will be the guest speaker.

• Georgia Master Cattleman Program starting Sept. 6. Tuesday evenings from 6:30–8:30 p.m. at the Ag Center. Eight classes. Cost is $75. Call for more information.

• Sept. 19: Home Gardening, Food Production and Nutrition Seminar will be held from 9:30 a.m. to 3:15 p.m. at the Chipley Co-op in Pine Mountain. You must pre-register with Harris County Extension at 706-628-4824.

• Market on Main: Every Saturday Morning from 8 to 10 a.m. Come by and enjoy the pick of the day. Carmike Cinemas LaGrange 10 theater parking lot at East Depot and Main streets.

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

By Brian Maddy

Contributing columnist

Brian Maddy is the ANR Agent for Troup County Extension. The Troup County Extension office is located at 114 Church St. in LaGrange and may be reached at 706-883-1675, Monday–Friday 8 a.m.–noon and 15 p.m.