Excerpt: Tetranychoid mites are plant feeders, and many of them are of considerable economic importance. Prior to the present study, only seven species of these mites were known from Michigan; Oligonychus ilicis (McGregor) (McGregor, 1931); Tertranychus mcdanieli McGregor (McGregor, 1931; Pritchard and Baker, 1955); Euryteranychus buxi (Garman) (Ries, 1935; McGregor 1950); Tettranychus atlanticus McGregor (Tuttle and Baker, 1964); Bryobia praetiosa Koch, Panoychus ulmi (Koch), and Tetranychus telarius (L.) (Ghate and Howitt, 1965)
