USDA scientists have linked the worst U.S. honeybee die-off on record—a staggering ~60% colony loss—to pesticide-resistant Varroa mites spreading deadly viruses, notably deformed-wing viral strains A & B, and acute bee paralysis virus. Mites resistant to the last line pesticide, amitraz, failed to stop the viral spread—signaling a massive warning for bee health and ecosystems.