Covers a minimum of 160,000 sq km. Genera found in northern temperate/boreal region. Kuchta, J.S. and Savage, J., 2008. Revision of the new world fauna of Mesembrina Meigen (Diptera: Muscidae) with the description of a new neotropical species. Zootaxa, 1689, pp.29-50; Huckett, H.C., 1965. The Muscidae of Northern Canada, Alaska, and Greenland (Diptera). Memoirs of the Entomological Society of Canada, 42:1-369.