After a decades-long hiatus, new world screwworm populations have surged in Central America and Mexico — and are inching northward.

The United States has suspended all animal imports from Mexico due to a parasitic fly that can produce flesh-eating maggots. New World screwworms are the cause of the indefinite suspension of animal ...

The U.S. has blocked imports of live cattle, horses, and bison through southern border ports following the resurgence in Mexico of the New World Screwworm, a parasitic fly that infects animals and ...