Miami Valley residents worried about their lush green lawns rapidly developing large brown splotches are not alone. Lawns across the region appear to be dying overnight not from a lack of rain, but from a far more insidious culprit: fall armyworms.
“I probably noticed it a few days ago,” Huber Heights resident Gary Blakeman told the Dayton Daily News Thursday. “At first I just figured ‘Well, it’s from the heat and the lack of rain,’ and then it looked like it was spreading.”
Then more than a third of his backyard lawn turned brown at a pace he had never seen in his nearly 40 years as a homeowner, Blakeman said.
When the company that treats his yard sent an email warning about the armyworms, he researched the topic and tested his yard, a process that proved the pernicious pests were to blame.
“I’ve always kind of prided myself on having a nice looking yard,” Blakeman said. “To see this happen as fast as it happened, is very frustrating. because I realize now ... later this fall, I’m going to have to rake all this up, get all this dead grass up and then put down new seed.”
The fall armyworms, which are actually caterpillars, return every few years to feast on local lawns, the last time being 2015, according to Pamela Corle-Bennett, state master gardener volunteer coordinator and horticulture educator for Ohio State University Extension.
As opposed to the common armyworm, which is always visible in Ohio to some degree, fall armyworms originate in South America and are found commonly in Southern states, Corle-Bennett said. Entomologists suggest the pests found their way to the area via recent storms.
They also can strike young crops, like a new hay field, a winter wheat field or a pasture.
“When they drop to the ground they look for places around turf grass to lay their eggs,” she said. “If it were brand new seeding of lawn, that’s perfect (for them).”
Armyworms lay their eggs in masses, so when they hatch, numerous caterpillars emerge all at once.
The voracious eaters, which have been around the past three to four weeks, have gone unnoticed until the last week or so, clandestinely consuming entire lawns.
“They’re so tiny when they hatch, they’re like an eighth of an inch, but you don’t see the damage, so it’s already happening early on in their life cycle,” Corle-Bennett said. “Then ... when they’re at that inch size, the larger, final stages, they will start eating just blades a day. It will seem like it (occurred) almost overnight, even though they have been around and been doing some damage. When they get to that size, then they can eat quite a bit.”
She said the easiest way to check if a lawn has armyworms is to take a gallon of water and mix in a tablespoon of dish soap, then pour it on brown spots on the lawn. If the worms are there, the soapy mixture will cause them to come to the surface.
They can be eliminated with pesticide sprays that have lawns listed on the label and contain bifenthrin, beta-cyfluthrin, lambda or gamma-cyhalothrin, permethrin, deltamethrin or other pyrethroids as ingredients, Corle-Bennett said.
Fall armyworms don’t kill a lawn as they don’t eat the crowns of turf plants, she said. “However, exposure to hot sun and drying winds will finish the lawn off,” Corle-Bennett said. ”Keep the crowns consistently moist and they will begin to grow. Thankfully the weather has cooled a bit as this helps recovery.”
Ohio State University entomologist Dave Shetlar cautions to be on the lookout for armyworms next season in early August, as they sometimes turn up a year after the first mass attack.
Rodger Reedy, said when a large area of his Beavercreek lawn turned “completely brown” in a short span of time, he wondered why it had dried out so quickly.
“As soon as I finished mowing, I put a sprinkler on it to get it wetted down pretty good,” Reedy said. Then, via social media, he happened upon reports of fall armyworm infestations and their effects, descriptions that precisely matched what had transpired on his turf.
“I went off and got some insecticide and I applied that yesterday,” he told this news outlet Thursday. “I’m hoping for the best.”
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