Taxonomy
Specimens of Bibio marci from the Natural History Museum’s Entomology reference collection in the Angela Marmont Centre for UK Biodiversity © Natural History Museum 2010
St Mark’s flies are members of the Diptera (true flies) and they belong to the family Bibionidae.
In the UK alone there are over 7,000 species of Diptera, including 20 in the family Bibionidae and 16 in the genus Bibio.