The New World screwworm is a species of blow fly in the family Calliphoridae. This fly received its common name because of its larval (maggot) stage’s feeding behavior, in which they cause extensive damage to the living tissue of warm-blooded animals using their sharp mouth hooks to burrow into their host. As of July 2025, dozens of cases have been reported in Chiapas and the most northernly case reported was in the Mexican state of Veracruz, 370 miles from the U.S. border.