Fall Armyworm Alert

This year has been a big one for fall armyworms, according to Rick Brandenburg, turf entomologist, North Carolina State University, Raleigh, N.C. These pests are still showing up in golf courses, home lawns, sod farms, newly lain sod and almost all other forms of green turf.

“They got into turf early, they came in record numbers and they have decided to stay well past their welcome,” he said. “A lot of turfgrass is still suffering from fall armyworms and there is no reason to believe this is going to change until we have a hard frost.”

Summer droughts only added to the problem because armyworms were forced to feed on lush turfgrass since much of the other vegetation was dry. “This made the fall armyworm numbers seem even higher in turfgrass since they congregated in such areas,” Brandenburg said.

In some instances where recent rains have given the turfgrass a flush of new growth, the damage is temporarily masked, Brandenburg pointed out. “I have seen all sizes of fall armyworms, but many this year are medium to large in size and can cause immediate damage,” he explained. “Fall armyworms often lay their eggs on shrubs, fence posts, signs and other objects and movement and/or damage often begins at the edge of the turfgrass.”

Lawn care operators should inspect clients’ turf closely this month, Brandenburg advised, adding that treatment late in the day is most effective. “I encourage everyone putting down new sod to keep a close eye on it over the next month and be ready to treat on a moment's notice,” he said. “A light irrigation prior to treatment may help, but don’t expect 90 percent control, especially if the worms were allowed to feed on growth for a week or so before treatment. The key to finishing out this year with some success is to stay on top of the problem."

The author is Managing Editor for Lawn & Landscape magazine and can be reached at nwisniewski@lawnandlandscape.com.