Scientists revive amitraz's power to save honeybees from deadly mites
Scientists have found a way to boost the effectiveness of amitraz, a common pesticide used to fight varroa mites in honeybee colonies. The discovery comes as resistance to the chemical grows, threatening bee populations worldwide. Researchers from the USDA Agricultural Research Service in Lubbock and the University of California, Davis led the study, backed by bee health grants.
Varroa mites pose a major risk to honeybees, weakening colonies through physical harm and spreading deadly viruses. Amitraz has long been a key tool for beekeepers, but genetic mutations in mites have made it less reliable over time.
The team identified a synergistic compound that blocks ATP-binding cassette (ABC) efflux transporters in the mites. These transporters usually help the pests expel pesticides, reducing their impact. By inhibiting them, amitraz becomes up to 50 percent more toxic—even against resistant mites.
While the method shows promise, the inhibitor also affects bees' own defences against chemicals. Future work will aim to refine the approach, ensuring it targets mites without harming bee resilience.
Improving amitraz's potency could cut treatment costs and labour for beekeepers. It may also slow the rise of further resistance, a growing concern as some mite populations now resist all major miticides.
The breakthrough offers a potential lifeline for beekeepers struggling with resistant varroa mites. Further research will focus on developing safer, mite-specific solutions. For now, the findings provide a critical step in protecting honeybee colonies from one of their biggest threats.
