High temperatures may intensify damage caused by the invasive pasture mealybug, according to early findings from Texas A&M AgriLife Research. Scientists are investigating how temperature changes the pest’s feeding behavior to help ranchers better predict and manage infestations that threaten Texas forage production.
The study is led by doctoral student Ashley Zavala in the lab of Thomas Chappell, an epidemiologist in the Texas A&M Department of Plant Pathology and Microbiology. The team focuses on mealybug feeding behaviors under various environmental conditions. These findings could assist ranchers in managing the invasive pest, which continues to spread across the state and impacts native and regionally adapted improved grasses.
Pasture mealybug was first confirmed in Texas in July 2025 and has since expanded to 114 counties, according to Texas A&M AgriLife Extension Service entomologists. The pest poses a threat to the forage and grazing lands that support Texas’ $15.5 billion cattle industry.
It has also been reported in Florida, Georgia, and Louisiana, with concerns that it could impact other agricultural production, including sugarcane and rice.
In pastures, immature mealybugs feed on plant sap and inject toxins that weaken grass, often leading to pasture dieback. Severe infestations can cause fields to turn brown, thin out, or die entirely. The pest affects a broad mix of native and improved warm-season grasses, including Bermuda, Bahia, and bluestems.
