High temperatures change how mealybugs feed, according to early findings from Texas A&M AgriLife Research scientists. The findings could help explain why some pasture mealybug infestations cause much more damage than others. 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.
Texas A&M AgriLife Extension Service entomologists said the pasture mealybug was first confirmed in Texas in July 2025. It has since spread to 114 counties. The pest has also been reported in Florida, Georgia and Louisiana. Immature mealybugs feed on plant sap and inject toxins that can weaken grass, often leading to pasture dieback.
To measure feeding, the team uses a method called electropenetrography, or EPG. A sensor attached to the insect and plant records feeding activity as a waveform. Chappell compared the waveform to an electrocardiogram.
Chappell said forecasting tools that consider feeding behavior, plant stress, susceptibility and weather could help growers time pesticide applications. Zavala said better understanding of what changes how the insects feed can help guide management.