Flies in several genera may cause myiasis (infection with the larval stage [maggots] of various flies) in humans, including, occasionally, flies in the New World genus Wohlfahrtia. Wohlfahrtia magnifica occurs in the Mediterranean basin, Near East, and Central and Eastern Europe; Wohlfahrtia vigil occurs in the northern United States and Canada. Adult Wohlfahrtia flies lay their eggs directly in, or in the vicinity of, wounds on the host. Larvae feed in the host for about a week, and may migrate from the subdermis to other tissues in the body, often causing extreme damage in the process.