The invasive insect that has been browning out Texas pastures may do its worst damage when it is hot, according to preliminary lab results that Texas A&M AgriLife Research released Monday.
The pest turned up in Texas for the first time in July 2025. AgriLife Extension entomologists now count it in 114 counties, and AgriLife describes it as a serious threat to the grazing land behind a cattle industry the agency values at $15.5 billion.
The immature insects suck sap from grass and inject toxins, and heavy infestations can leave fields thin, brown or dead a condition AgriLife calls pasture dieback. Bermuda, Bahia, bluestems and other common warm-season forage grasses are all vulnerable.
What the lab measured
Doctoral student Ashley Zavala, working in the lab of Thomas Chappell, an epidemiologist in Texas A&M's plant pathology and microbiology department, is using electropenetrography to track mealybug feeding across a range of conditions. The technique wires both the insect and the plant into a circuit and turns feeding activity into a waveform, which Chappell likens to reading an electrocardiogram.
The lab is running the work on a related mealybug that feeds on peppers, and Chappell said he sees a clear link to the pasture species.
Two findings stood out. Chappell said that as temperatures climb, the insects may drink more from the xylem, the tissue that moves water through a plant, to stay hydrated. Heat also made them salivate into the phloem more often. Because the saliva is what delivers the damaging enzymes and toxins, the release says the same number of insects could cause more harm during hot spells.
