In July, Texas A&M AgriLife pest specialist Danielle Sekula got a strange call from farmers in South Texas, where she works. While mowing hay, their machine looked like it caught on fire. But there were no flames.
When Sekula arrived, she saw thick, greyish vapor billowing out of a mower rolling through a hay field. The farmers didn't know what was going on. Sekula did.
"They were like, 'It's not on fire,'" said Sekula. "And I was like, 'Oh man, that's pasture mealybug.'"
Pasture mealybugs are miniscule, powder-white pests. The field was so infested with them, that the smoke Sekula saw was composed of the insects' chopped up remnants.
More questions than answers
Pasture mealybugs first appeared in South Texas in 2022. They've now been found in 114 counties, stretching from the Rio Grande Valley to the Oklahoma border.
"We don't know a whole lot about them," said David Kerns, associate head of the entomology department with Texas A&M University.
The insects were first identified in Australia. Kerns says it's unclear how they got to Texas, but they've since spread to Louisiana, Georgia and Florida. He theorized that they could have been blown here by high winds from the Caribbean, where they're also found.
"They do like it hot and humid. And particularly, they like thick, tall, grass," Kerns said.
Some of the bugs live in the soil over the winter, though it's unclear how many of them survive, and what weather cues bring them back to the surface. Farmers and researchers report that their populations can balloon after big rains.
Kerns told the Texas House Agriculture and Livestock Committee in October that pasture mealybugs could cost Texas farmers and ranchers $2 billion per year. They are so small that infestations can be mistaken for some kind of mold.
"Boy the first time I looked at them, if I would have looked at that and not had somebody telling me what it was, I would have thought it was a fungus," said William Steubing, a rancher who runs cattle between San Marcos and Lockhart.
Steubing's mother, Doris, first spotted the problem on their property when she noticed portions of a 50-acre bluestem pasture starting to wilt.
"You know you'll get bald spots in your pasture here and there, that's not a big thing. But there were physically dead plants in there," William Steubing said.
Mealybugs weaken grass by injecting a toxin into the plant and sucking out its sap. The affected grass will often turn yellow, then red or purple, then die. In serious infestations, it will not grow back.
Steubing didn't know what to do. At the time, there was no approved pesticide for the insect. So he came up with his own solution.
"I thought, well you know what, let's hit 'em with a bunch of soap and just see what happens," he said.
He thinks it helped, but Steubing also spread other pesticides in the pasture, so he can't be sure to what extent.
A costly problem
Other farmers were so desperate to get rid of the mealybugs that they experimented with pesticides on their own to try to find something that would kill the bug.
"There's definitely ways we were able to mitigate the problem. It seems like we found that chemigation works best for us being able to get that insecticide in the soil," said Colin Graff, who runs aforage business with his wife in Hondo.
Graff grows grass for a living. He said that pasture mealybug "hammered" more than a thousand acres of his fields this year. Graff stressed the importance of cutting the grass before treating it, because the bugs generally stay close to the soil.
"We've been able to recover from it, but it's not something to take lightly, that's for sure," Graff said. "That thing freaking wreaked havoc down here."
The insects likely spread by hitching a ride on farm equipment or animals, and by the wind.
In recent months, Kerns, the A&M entomologist, has fielded dozens of questions a day from farmers and ranchers who have questions about pasture mealybug. He recorded audio alerts that producers could get sent directly to their phones with the latest information on the bug. And he made it a priority to find something that reduced mealybug populations.
"We did, I don't know, probably, between me and my colleagues, dozens of [pesticide] tests," he said.
A pesticide called Centric 40WG performed best in their trials. In August, the Environmental Protection Agency gave emergency approval for farmers and ranchers to use Centric to treat pasture mealybugs.
Kerns said it works, but at approximately $15 per acre it costs more than some farmers want to pay. Some retailers are sold out of the chemical.
"I wish I could half the price or something, but we can't," Kerns said.
Steubing, the rancher, said he spent between $7,000 and $8,000 to get rid of pasture mealybug on the 50 acres they infested on his property. His cattle are currently grazing that area, and he will spend even more money to spray them down with a pesticide before letting the animals into another part of his property.
Between the pest depleting their pastures and the cost of pesticide, some cattle-raisers have had to sell animals prematurely. They may have to get rid of more if the cost of hay is too high this winter.
Even if researchers find better treatment options, Kerns doesn't think Texas will ever be entirely rid of the pest.
He's now researching whether certain pasture grasses are more resistant to the mealybug than others.
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