The 'common yellow dung fly'. One of the most abundant and ubiquitous of British flies. 'Typical' males are yellow and furry, whilst females are greenish and bristly. However, smaller males frequently lack the yellow furry appearance and are more like a female in general appearance. These were sometimes given specific status (S. merdaria) in the past, although most recent works refer to these (if at all) as no more than a colour form. Small individuals may be sterile (Gibbons, 1980). Large and rather more orange coloured males seem to occur in northern Scotland which could easily be mistaken for S. scybalaria. Wing length: ♂ 4.9 - 7.4 - 9.5 mm (54); ♀ 4.1 - 6.2 - 8.0 mm (62).