ABSTRACT
The most recent revision of North American blow flies was by Hall (1948); however, Hall’s keys have proven to be difficult to use because of his heavy reliance on proportional measurements of characters and the fact that he measured no more than five to ten specimens per species. He also chose specimens representing size extremes rather than “average” individuals (Sabrosky et al., 1989). Subsequently, James (1953, 1955) and Hall and Townsend (1977) provided revised keys, which clarified the identification of regionally selected species. James addressed the Western species of blow flies, while Hall and Townsend provided keys to blow flies found in Virginia. Shewell (1987) provided a key to the genera of North American calliphorids, but did not key species. Rognes (1991) reviewed Palearctic and Holarctic species and recommended numerous changes in blow fly taxonomy. Many of his name changes affected taxa found in North America.
