Cool weather slows armyworm advances, but another flush possible

COLLEGE STATION – Following rains, armyworms marched in and devoured improved pastures and wheat throughout the state. But the worst may be over -- or not -- according to Texas AgriLife Extension Service personnel.

They say producers could see another flush of armyworms depending on the weather.

"Conditions are improving, but the biggest problems we do have right now are the cooler weather – as far as forage production goes -- and then the onset of armyworms," said Dr. Ron Gill, AgriLife Extension livestock specialist, College Station.

Gill said he's had reports for armyworms from across the state, but they are spotty.

"For example, in North Central Texas, around Decatur they're very heavy and out west of there, but south of Decatur about 15 miles, there's not any activity," he said. "Also out in the Rolling Plains area, the wheat pastures are going to be susceptible to armyworm infestations as well as greenbugs at a future date." AgriLife Extension agents for agriculture reported armyworms in Baylor, Bosque, Burleson, Clay, Ellis, Grayson, Hamilton, Hardeman, Johnson, Kaufman, Knox, Lamar, Montague,Van Zandt, Wise, Wood and Young counties.

Gill noted that armyworms are relatively easy to control if they're detected early. When the worms are large, they are hard to control.

"One of the problems we are having this year is that there seems to be several hatches occurring in the same area, so all the worms are not the same age," he said. "That may present a problem when you go in to control them; you may have to spray multiple times."

Based on last year's prices, a single treatment can be as low as $7-$8 per acre, which includes materials and the cost of application, he said.

Dr. Allen Knutson, AgriLife Extension entomologist based in Dallas, said cooler weather has slowed the maturation of the current armyworm population and reduced the likelihood of them becoming adults and laying more eggs.

"However, we could still have moths migrating in from southern areas that are currently depositing eggs, so additional worm populations could develop," he said. "For these reasons, warm weather could prolong the armyworm threat. Usually cooler weather in November puts a halt to armyworm problems, but that's weeks away."