Invasive pasture mealybug could cost Texas agriculture $2 billion a year

Pest detected in South Texas in 2022 has spread to Louisiana, Georgia and Florida

The first sign of trouble at one South Texas hay field last July was a mower that looked like it was catching fire. White smoke appeared to pour from the machine as the farmer cut hay, though no flames were visible, and he called Danielle Sekula, a pest specialist with Texas A&M AgriLife who works with farmers near the Rio Grande Valley. Video of what she found shows thick, grayish vapor billowing from the mower as it rolls through the field — chopped-up remnants of pasture mealybugs, minuscule insects infesting the grass so densely that they streamed out of the machine like smoke. “And they’re like, it’s not on fire. And I was like, oh, man, that’s pasture mealybug,” Sekula said.

Pasture mealybugs first appeared in South Texas in 2022 and have since spread into Louisiana, Georgia and Florida, according to reporting by Michael Marks of the Texas Standard, produced for NPR. The insects are difficult to detect, and their arrival adds another stressor for farmers and ranchers already stretched by high fertilizer and diesel costs.

David Kerns, an associate head of Texas A&M University’s entomology department who has been helping lead the response to the pest, estimated the mealybug could cost Texas farmers and ranchers $2 billion per year. Much about the insect remains unknown. “Well, we don’t know a whole lot about them,” Kerns said. The bugs favor hot, humid conditions and, particularly, “thick, tall grass,” he said.

The insects weaken grass by injecting a toxin into the plant and sucking out its sap. Affected grass often turns yellow, then red or purple, before it dies.

The pests are small enough that some growers mistake infestations for white mold. William Steubing, who runs cattle with his family in Central Texas on land that has been in his family since the 1890s, said the insects are easy to miss. “They’re easy to overlook,” Steubing said. “If I would have looked at that and not had somebody tell me what it was, I would have thought it was a fungus.”

His mother spotted the problem first, when she noticed portions of a pasture starting to die. “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,” he said.

The mealybug does not feed only on hay. Florida farmers first identified the pasture mealybug in late May, after most of the year’s sugarcane had already been harvested, according to the report. Julien Beuzelin, a University of Florida entomologist who works with sugarcane, said the crop now growing is suffering from the pest, and that infestation degrades the plants. “The integrity of the stalk — it is not the same. The stalks become rubbery,” Beuzelin said. “So again, you have an insect that can be devastating.”

Beuzelin said the pest’s reach extends across Florida’s sugarcane fields: “I really believe that if you scout hard enough, you will find at least one mealybug in every single field.”

The Environmental Protection Agency has approved several pesticides to fight the insects, but none are a silver bullet, according to the report. Kerns said the treatments cost more than some farmers want to pay. “I mean, I wish I could halve the price or something, but we can’t,” he said.

Kerns and Beuzelin are now focusing on learning more about the pasture mealybug itself and on whether certain crops may be more resistant to its effects.