Clint Peck (Beef Magazine)
Jul 10, 2026
An alert is being issued for an insect pest that’s threatening pastures and hayfields across a wide swath of the Southeast U.S.
At a glance
The pasture mealybug has infested 70+ Texas counties in just two years.
The pest has spread across 15 Florida counties just this summer.
Pasture mealybugs can thrive on nearly all warm-season grass species.
There are currently no insecticides labeled to control pasture mealybugs.
As if Southeast U.S. cattle ranchers don’t already have their hands full with the New World Screwworm, they’re now facing another insect pest. This one is attacking their fields and pastures. And while it’s almost socially incorrect to use the term “spreading like wildfire” these days—that’s the best way to describe what’s happening with the pasture mealybug.
Populations of Heliococcus summervillei are exploding in Texas and Florida—with the pest posing a serious threat to millions of acres of grass pastures and hayfields in adjacent states.
Pasture mealybug infestations were first reported by a handful of South Texas livestock producers in April 2025. By mid-summer last year, the invasive pest was documented across 22 southeastern Texas counties.
As of July 1, 2026, pasture mealybugs were reported in 70 Texas counties stretching from the upper Rio Grande Valley east to Louisiana and the Gulf of Mexico.
“We thought we were seeing something odd in grass pastures back in 2023 and 2024,” said Gregory Wilson, entomologist with Texas Agri-life Extension. “Now, we know; and it’s here with a vengeance. We have little idea of its limit and the range in which the pasture mealybug is capable of spreading.”
Those early observations were presumed to be caused by the Rhodes grass mealybug (Antonina graminis), which has been reported in the U.S. since 1942. However, further investigations identified H. summervillei as the species of concern.
Pasture mealybugs showed up in Florida with a vengeance this spring. The pest has now been reported in 15 Sunshine State counties. Surveys are ongoing to determine its distribution and movement. Forage specialists there say the pest can be responsible for the rapid decline of an entire field—sometimes nearly overnight.
Mealybug infestations can invade virtually all warm season grasses, including sugarcane and can even invade the edge rows of sorghum and corn fields.
Fortunately, pasture mealybugs do not threaten broadleaf plants such as legumes and brassicas, which are immune to the pest, said Issac Esquivel, University of Florida assistant professor of entomology and nematology.
A pasture mealybug is a small, white, oval-shaped insect that appears slightly fuzzy or fluffy. It’s particularly small—one-eighth to one-quarter inch long—and looks almost identical to non-problematic mealybugs.
Esquivel urges livestock growers and hay producers to carefully watch their fields for changes that might indicate a mealybug infestation and contact their local Extension office if they sense a problem. When scouting fields, he said to focus on areas showing yellowing, reddening, stunting, or drought-like symptoms.
“Carefully inspect the underside of leaves, plant crowns, thatch, and soil surface for white, waxy insects,” Esquivel said. “Mealybugs will start in a hot spot and take over a whole field within one to two weeks.”
Immature pasture mealybugs feed by sucking plant sap with piercing/sucking mouthparts. They excrete a sugary substance called honeydew over the leaves. This substance promotes the growth of sooty-mold fungi, which block photosynthesis.
In Louisiana, pasture mealybugs were confirmed last summer in sugarcane fields in Vermilion and Iberia parishes. Entomologists are hot-footing it across the state trying to track and report the pest’s spread.
Louisiana forages specialists have developed a technical data sheet to help producers learn more about mealybugs. In Mississippi, producers who suspect this pest might be moving into their pastures are asked to contact the Mississippi State University Extension Service.
Significant pasture mealybug problems have not yet been reported in Georgia or Alabama, although as those states are in the path of the pest, it might be just a matter of time.
The origin and spread
Likely native to Southeast Asia, H. summervillei was first identified in Queensland, Australia, in 1928. Since then, mealybugs have become a major pest linked to severe “pasture dieback” across the island continent.
In the Western Hemisphere, mealybugs were first detected on some Caribbean islands between 2019 and 2020—specifically Puerto Rico, Hispaniola, Barbados, and Cuba. It’s believed juvenile mealybugs were carried from the Caribbean to the U.S. mainland by tropical storms —especially the coastal areas of Texas, Florida, and Louisiana.
Wilson said wind is likely a major cause of the pest’s spread over land. He said that humans and their machinery are also a way mealybugs can move. Activities like roadside and median mowing can blow the pest along Interstates, state highways, and county roads.
“Shared mowing and hay harvesting equipment, and infested planting implements are suspected pathways for spread,” Florida’s Esquivel explained. “Cleaning equipment before moving between fields is strongly encouraged.”
Wilson noted that while hay that’s dried and cured well in the field is not a good host for the pest, he agreed producers should be vigilant with regard to the movement of haying equipment from field to field.
There’s evidence that pasture mealybugs can also move into the soil to feed on roots—and they often survive cold winters. Therefore, there’s concern that these mealybugs could spread significantly north past the frost-line regions of the country.
David Kerns, Texas AgriLife Extension entomologist, said the pest continues to expand at an alarming pace. He added that in addition to the Texas counties with confirmed cases, there are probably another 56 counties considered as imminently threatened.
“It seems like we add new counties every week, sometimes every day,” Kerns said. “I get up to a dozen calls every day from producers who think they have them in their pastures.”
At this point, there are no labeled pesticide products approved to effectively control pasture mealybug. One labeled product—Sefina—has shown some ability to suppress low populations in pastures. But he said the product may not be effective in controlling high mealybug populations.
Kerns said while there’s a lot yet to learn about pasture mealybugs, he thinks eventually the pest can be controlled. He’s in the process of submitting an emergency insecticide use exemption with the Environmental Protection Agency for pesticides that have been shown to be effective in test trials.
Current recommendations focus on early detection, reducing dense grass canopies through grazing or hay harvest, and preventing movement of insects on animals and equipment between fields.
“Pasture mealy bugs love tall, dense grass canopy,” he said. “So if you think you have them and your pasture is close to a cutting, cut it and bale it. That will reduce the populations considerably, and the short grass is not going to be hospitable to those remaining.”
“Pasture mealybug and New World Screwworm are a potential one-two punch that our producers hope to avoid,” said David Anderson, Texas AgriLife Extension economist and professor. “To have one pest threatening the grass our animals need, and another threatening the animals themselves, poses some serious challenges.”