The Fall and Rise of Screwworm

Every spring, as sure as the seasons, and for generations unknown, screwworms began their annual march northward from their overwintering sanctuaries in Mexico and South Texas. Pushed by an unknown force as inexorable as gravity, screwworms moved north — ever moving, ever spreading, ever multiplying, ever destroying. No army ever advanced any more surely or methodically. No army was ever more destructive. Attacking, killing, maiming, and destroying, screwworms literally ate their way north. Reac...