Pasture mealybug raises alarm for livestock producers
By Adam Russell
Texas AgriLife
As Texas producers come to grips with the threat of New World screwworm, another new invasive pest — pasture mealybug — is casting a growing shadow over the state’s forage and livestock industries, according to Texas A&M AgriLife Extension Service experts.
The pasture mealybug continues to spread rapidly across Texas, threatening pastures, hayfields and forage resources that underpin the state’s $15.5 billion cattle industry as well as the state’s other pasture-based livestock industries.
AgriLife Extension entomologists first confirmed the pest in Texas in 2025. The insect has been confirmed in 70 Texas counties so far. The insect feeds on a wide range of native and improved warm-season grasses, including Bermuda grass, Bahia grass, bluestems, johnsongrass and other important forage species.
Immature mealybugs feed on plant sap and inject toxins that weaken plants, often resulting in a condition known as pasture dieback. In severe cases, fields can turn brown, thin dramatically or die outright.
David Kerns, Ph.D., AgriLife Extension statewide integrated pest management coordinator and associate department head in the Texas A&M Department of Entomology, Bryan-College Station, said the pest’s distribution continues to expand at an alarming pace.
“It seems like we add new counties every week, sometimes every day,” Kerns said. “We have counties with confirmed cases, and there’s probably another 56 that we consider as being imminently threatened. I get up to a dozen calls every day from producers who think they have them in their pastures.”
Control options remain limited
What concerns Kerns most is the pest’s broad host range, the lack of any truly resistant forage grass and the lack of pesticide control options.
Kerns said AgriLife Extension and Texas A&M AgriLife Research experts have been evaluating management options while working to better understand how the pest spreads and how producers can protect valuable forage resources.
However, at this point, there are no labeled pesticide products approved to effectively control pasture mealybug. Kerns said one labeled product — Sefina — has shown some ability to suppress low populations in pastures.
He is in the process of submitting an emergency insecticide use exemption with the U.S. Environmental Protection Agency for pesticides that have 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. Kerns said tests have shown that pasture mealybugs are highly unlikely to survive beyond two weeks in baled hay.
“Pasture mealybugs 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.”
Kerns also is concerned because he suspects that early life stage pasture mealybugs could be dispersed by prevailing winds. The pest’s distribution is too widespread to be explained by equipment or livestock movement alone.
Researchers are investigating wind dispersal as a working hypothesis, as that scenario offers the most plausible explanation for the pest’s rapid expansion, he said.
Producers are encouraged to contact their local AgriLife Extension office to report potential infestations or for updates and guidance on monitoring and management.
Economic impacts ripple from the pasture
The potential economic implications related to pasture mealybug are staggering.
Recent assessments by AgriLife Extension experts estimate that 20.4 million rangeland and improved pasture acres lie within infested counties. Counties considered under imminent threat of infestation raise that total to 35.7 million acres.
David Anderson, Ph.D., AgriLife Extension economist and professor in the Texas A&M Department of Agricultural Economics, Bryan-College Station, said early estimates suggest annual direct forage and grazing losses for Texas could range from approximately $100 million to more than $1 billion depending on infestation severity and acreage affected. Some improved forage varieties, particularly Bermuda grass hayfields, can require expensive reestablishment if stands are lost.
If widespread pasture replanting becomes necessary, one-time reestablishment costs could be $1 billion to $2 billion statewide.
Texas’ livestock industry depends on healthy, productive forage systems. Reduced grazing capacity also means higher supplemental feed costs, lower stocking rates and increased financial pressure on ranching operations. Hay producers could face reduced yields and declining stand quality, while wildlife enterprises and hunting operations may also be affected by widespread habitat degradation.
“Pasture mealybug and New World screwworm are a potential one-two punch that our producers hope to avoid,” Anderson said. “To have one pest threatening the grass our animals need and another threatening the animals themselves poses some serious challenges, but ranchers are a resilient bunch.”
AgriLife Extension district reporters compiled the following summaries:
PANHANDLE
Spotty showers moved through parts of the district, with some areas receiving around half an inch while other locations remained dry. Topsoil and subsoil moisture levels were very short to short. Warm daytime temperatures held steady, and overnight lows were noticeably higher than in previous weeks.
Wheat harvest continued in scattered fields, but most acreage intended for grain was already delivered to storage. Corn was planted back on many wheat and small grain fields cut for silage in late May and early June. Standing residue from wheat fields was being baled and stacked.
Cotton showed considerable uniformity across the district, with most fields reaching the five- to six-leaf stage and nearing first square. Early symptoms of late-season decline and interveinal chlorosis were appearing in scattered corn and sorghum fields. Pasture and rangeland remained in very poor to fair condition.
SOUTH PLAINS
Rainfall was highly variable across the district, with amounts ranging from a few tenths of an inch to as much as 5 inches in localized areas. Most of the heaviest totals fell over pasture ground.
Hail struck the central portion of the district and wiped out some cotton fields, and producers were weighing whether to plant grain behind the damaged acres. Corn and sorghum fields also sustained hail damage in some areas.
Producers focused on watering, weed control and early plant growth regulator decisions on cotton, and a few pockets of miticide applications were made. Cotton progress varied widely, with plants ranging from three to 11 nodes and square set generally above 80% where moisture was adequate.
Peanuts were blooming, with pegging and pod set beginning, running roughly 10 days behind normal. High winds and hot temperatures stressed crops in drier pockets, and some fields appeared to be drying up.
Wheat harvest neared completion in some areas, with below-average yields reported. Cattle were in good condition where forage improved, though a few producers continued to feed supplements in areas that missed the rain.
ROLLING PLAINS
Hot, windy conditions dominated the district and escalated evaporation rates. A late-week deluge dropped more than 1 inch of rainfall on localized areas, but most of the district stayed dry.
Cotton planting wrapped up, and emergence was spotty where moisture was inadequate. Wheat yields came in at 60-70 bushels per acre in some areas, and corn harvest was starting on early planted fields with sorghum not far behind.
Coastal Bermuda grass hay was cut in large volumes with good quality and tonnage, and Sudan grass and haygrazer fields did well where they caught extra rain. Some earlier Sudan grass plantings showed signs of extreme moisture stress.
Wildlife food plots came up nicely following fertilization. Deer and feral hogs were active in bottomland areas. Livestock conditions ranged from poor to excellent, and producers in the drier areas continued to supplement their diets.
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