Tabanus autumnalis, the
large marsh horsefly, is a medium-sized species of biting horse-fly. It is somewhat scarce compared to
T. bromius and
T. bovinus. This species shows slightly more of a preference for coastal marsh than some of the other European
Tabanus, sometime even found in saltmashes. Wing length is 13–16 mm and about 16–22 mm in body length.
(Wikipedia)