Campbell Vaughn: Armyworms are on the move, wreaking havoc on lawns. Here's how to beat them.
When we get information from UGA about pest attacks that are spreading across the state, I usually take note. And I have been hearing it a bunch from my Extension friends from other counties that aren’t too far away from us.
Currently, fall armyworm are moving around the state and are being confirmed near us in large numbers.
The fall armyworm is the caterpillar of a moth that arrives in Georgia almost every year from Florida. Traveling via weather fronts, these moths spend the spring and summer traveling from south to north gradually infesting our entire state.
Even in relatively mild years, the moths, which would be considered adults, do not survive our winters, so they must start their yearly Sunshine State exodus over every spring.
The reason we don’t normally see the armyworms until about this time of year is the life cycle takes several generations of moths to work all the way north to the Garden City.
An armyworm moth can lay eggs in batches of a few dozen to several hundred, allowing populations to grow rapidly throughout the summer. These eggs hatch after a few days and the caterpillars feed on mostly Bermuda and bahiagrass, grow for two to three weeks and then pupate. A week or so later, the new adult moth emerges to start the cycle again. In the warm weather of summer, the cycle takes about four weeks to complete with 14 to 17 days spent as caterpillars feeding on the grass.
These infestations can wreak havoc on golf courses, ball fields, hay pastures and on occasion my backyard. Usually, the damage is just the loss of the leaf blade of the grass, and it will grow back, but occasionally they can cause more serious harm. Hay farmers can lose an entire cut cycle from armyworm infestation, which can really put a dent on these hard-working farmer’s bottom line.
One evening a couple of years ago, I looked out the window into my backyard Bermuda lawn and saw my turf had a little yellow tint to it. My mower blade has been a little screwy and it has been too hot to mess around fixing it, so I thought it might be the cut I made when I mowed it a couple of days before.
When I walked outside to check it out, I grabbed a 2-gallon bucket that we use to wash cars, added a couple of squirts of dish soap and filled it with hose water. I took the bucket out to an area of the lawn that looked dull and dumped it on the grass. Ten seconds later, caterpillars in droves began to surface. Of course, me being the nerdy educator I am, I made my wife and daughter come out to watch me do it again so they could see it, too. Apparently, fall armyworms hate bathing so they race to the surface to complain about being all soaped up. It was a cool trick to watch.
One armyworm spotted doesn’t mean we need to send in a crop duster, so remember to be safe and read the labels on any control products before applying to your landscape.
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The threshold for treating an infestation is three or more caterpillars per square foot of turf. For homeowner control of armyworm infestations, consider using the active ingredient spinosad (Bonide Captain Jack’s) which is considered organic. Sevin with carbaryl is also a safe insecticide.
Since I was only spot spraying a smaller area, I personally used permethrin that worked very well. Please try to apply late in the evening or early in the morning when pollinators are not as active.
It is hard to say how long the armyworms can be active but stay on the lookout for them at least until the end of September or the first part of October.
This article originally appeared on Augusta Chronicle: Campbell Vaughn: Tips to get rid of armyworm infestations in lawns