Pasture mealybug raises alarm for Texas livestock producers

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 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.”

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 hay fields, 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.

North

The district experienced its warmest week in some time, with temperatures in the upper 90s and heat indexes well over 100 degrees. Rainfall totals reached up to 1 inch in some areas, though hot and windy conditions reduced topsoil moisture. Corn was in good to excellent condition and drying down rapidly, and harvest was expected earlier than normal. Silage corn was already being cut in some areas. Soybeans looked strong across the district. Wheat harvest was in full swing alongside heavy hay activity, with early cut hay fields already going into a second cutting. Nuisance flies — house, stable and horn flies — remained heavy, and mosquitoes were a major issue at dusk. Powdery mildew, downy mildew and black leaf spot were affecting garden crops. Livestock were in fair to excellent condition, and feral hogs remained active where soils stayed moist.

East

Scattered showers delivered from trace amounts up to 2 inches through parts of the district. Highs pushed into the 90s while overnight lows held in the 70s. Hay production ran at a rapid pace with forage conditions described as very good for this time of year. First cuttings were widely completed, and producers watched fields closely for armyworms and pasture mealybugs. Field peas, tomatoes, okra, late squash, beans and watermelons were being harvested with good yields. Livestock markets remained strong, with prices for feeder calves over 400 pounds firm; slaughter cattle prices were firm to $5 stronger per hundredweight; prices for calves were steady to $10 higher per hundredweight, and bred cows and cow-calf pairs topped at $5,000 and $5,100. Fertilizer prices had some producers cutting back applications. Feral hog activity continued to cause damage to fields. Livestock were in fair to excellent condition, and pasture and rangeland ranged from poor to excellent.

Far West

Rainfall was highly variable across the district. The Big Bend region continued to see widespread rainfall with highs in the mid-80s and improving range conditions. High temperatures in the upper 90s to low 100s and sustained winds over 10 mph pulled topsoil moisture down in the eastern portions of the district and made herbicide applications difficult. Pima and upland cotton looked very good in the El Paso area with little pest pressure. Pecan orchards were being irrigated, and some stink bug pressure was noted. Alfalfa and grass hay operations continued to produce well. Melon harvest was slow but of good quality, with production expected to pick up. Range and pasture conditions ranged from very poor to good. Livestock were in poor to good condition, with some pink eye cases expected following a windstorm. Supplemental feeding continued in the drier pockets.

West Central

One area reported major storms and heavy rainfall, but most of the district received little to no rain. Hot, dry and windy conditions prevailed across most of the district, with high temperatures ranging from the upper 90s to the low 100s.  Drought stress became more apparent in range and pasture grasses as well as some crops. Forage sorghum was being cut for hay, improved grass pastures were being baled, and haygrazer was drying up in the driest pockets. The pecan crop looked strong, with one area crediting last July’s flooding as beneficial. Grain sorghum was in fair condition, and cotton was in mostly fair to good condition following good emergence. Prices for lightweight stocker steers were $10 higher per hundredweight; packer cows were $5 higher, and the top bull at $253 per hundredweight. Pasture mealybug was identified, and producers were advised to scout. Livestock remained in good condition, though supplemental feeding began in some areas.

Central

Topsoil moisture ranged from very short to surplus. Heat increased across the district and pushed corn to maturity faster than expected, with harvest 20-25 days out in some counties and silage harvest already complete in others. Growers expressed concern about corn test weights given the rapid dry-down. Cotton continued to progress nicely with minimal pest issues and benefited from the accumulated heat units. Hay producers stayed busy with lush growth from delayed first cuttings. Producers reported widespread flare-ups of pasture mealybug. Considerable insecticide spraying was underway with poor effectiveness reported and heavy hay yield losses expected from stand kill. The pest was also turning up on urban lawns in at least one city. A few armyworms were reported in the southeast parts of the district. Pasture and rangeland conditions were very poor to excellent. Stock tank levels remained adequate, and livestock stayed in good body condition. Wildfire risk increased where soils dried fastest.

Southeast

Weather shifted from wet to dry across the district, with hot temperatures and a few showers reported. Plants were also beginning to show stress. Rice was heading or beginning to head, with harvest still a few weeks away. Corn and cotton continued to grow. Wheat harvest was complete, and first-cutting hay was underway. Hay yields were high, but quality suffered from the wet May and June. Pasture mealybug infestations were reported across multiple counties in Bahia, Bermuda and Tifton grasses and remained the primary concern for forage producers. Heat stress showed up in cattle herds, with European breeds struggling most. Pastures were still green, and pond levels were good. Pasture and rangeland conditions were fair to good, and livestock conditions were fair to good.

Southwest

Hot, dry conditions settled over most of the district, and moisture declined noticeably after a wetter stretch. Producers took advantage of the dry weather to harvest and bale hay, with first cuttings baled and regrowth looking ideal in some areas. Corn was drying down. Pasture mealybug was causing forage losses in several areas — reducing grass growth and, in some cases, killing pastures outright. Armyworm concerns remained elevated, and first cuttings of haygrazer began in some areas. Livestock remained in good condition and continued to graze with minimal supplementation in most areas, though producers in the driest western pockets began heavily supplementing cattle diets. White-tailed deer had largely finished fawning.

Coastal Bend

High temperatures and two-plus weeks without rain dried the district quickly, though conditions allowed hay producers to catch up in a hurry. Corn and grain sorghum harvest got underway on early planted fields, and harvest aid applications were made to grain sorghum ahead of cutting. Some sorghum showed head sprouting damage, and cotton reached cut-out on a portion of the acreage. Isolated showers late last week delayed corn and sorghum harvest in some areas as farmers waited for topsoil to dry. Hay yields were average to above average except where pasture mealybugs were found. Pasture mealybug dispersal was described as broad across some areas with potentially significant pasture impact. Livestock water levels were becoming a concern. Range and pasture conditions were fair to excellent, and livestock continued to gain condition with plentiful forage.

South

Triple-digit heat gripped the district with essentially no rainfall, low humidity and warm overnight lows in the upper 70s through the week. High temperatures ranged from the upper 90s to around 100 degrees or more in some areas. Grain sorghum harvest was progressing well, and corn harvest began as fields dried rapidly; yields varied from field to field. Cotton continued to develop well, putting on blooms and bolls, and sesame fields were progressing under the hot conditions. Hay producers moved large volumes of both square and round bales while forage remained plentiful. Cantaloupe season concluded in one area. Wildlife observations improved, with white-tailed fawn sightings increasing and quail and turkey poults hatching. The New World screwworm remained the dominant concern alongside pasture mealybug. Some producers were selling calves and cull cows on strong markets amid screwworm quarantine concerns. Livestock conditions were fair to excellent, and pasture and rangeland ranged from very poor to excellent.