How to Kill Armyworms in Memphis
Our branch manager in Memphis, Stuart, says that army worms are invading! Greg, our branch manager in Birmingham confirmed that they’re having a problem with them also. And yesterday, James, our branch manager in Tulsa, told me they’ve seen 2 cases of them. This is really bad news! Army worms can munch their way across your lawn pretty much overnight and leave a raggedy mess behind as they move on to the next lawn.
What we’re seeing now are Fall Armyworms, so named because they don’t reach the northern states until fall. They are caterpillars that turn into moths. The latin name is Spodoptera frugipeda. They overwinter in Florida and Texas, where they lay eggs. When the larvae hatch, they eat for awhile, turn into moths and head north to lay more eggs. Mature caterpillars are about 1 ½ inches long. The farther south you are, the more generations of armyworms you’ll see in a summer. In Florida, armyworms are the most damaging pest to corn crops.
We have seen fall armyworms in all of our markets at one time or another, usually following periods of drought. Sometimes, they show up in just a few lawns, and other times they can cause considerable damage in very little time. About 10 years ago, armyworms moved into Tulsa in huge numbers! There were so many caterpillars, it looked like the lawns were moving!
Fortunately, armyworms aren’t difficult to kill. We recommend a liquid insecticide like Sevin. However, bear in mind that you may see several generations, so you may need to apply it more than once. If you don’t want to mess with that, ask your lawn tech for a quote to spray your lawn for you.
The real danger of armyworms is that they can damage your lawn at a time when drought and high temperatures are also a problem. If they chew up your fescue lawn, it will not recover and you will have to reseed this fall (all fescue should be overseeded each fall anyway, but it will look bad until then.) If you have a bermuda, zoysia, or St. Augustine lawn, it may not have enough time to recover before the winter, depending on the amount of damage. Thin or stressed turf is much more susceptible to winterkill than healthy, thick turf. If your grass doesn’t recover completely before the winter, it may be further damaged by cold temperatures, freezing and thawing, ice and snow, etc. And THAT will show up next spring when it doesn’t green up.
So, if you see ’em, spray ‘em. The sooner the better! And if your bermuda is damaged, water, fertilize, and mow frequently to try to get it fully recovered before fall.
Channel 3 in Memphis reports on the armyworm invasion with a short video that will give you a good look at these critters.