Liopterus haemorrhoidalis

Apparently a very common species and widespread in Norfolk but presumably it doesn't come to light very readily as I've only recorded it once. It's the only member of the subfamily in the UK.

This was in my garden moth trap. Although superficially similar to several Dytiscidae there was something about this that made me suspect it was not a species I'd encountered before - not sure exactly what it was but maybe a vaguely Rhantus-like colouration but more the size of one of the smaller Ilybius. Anyway, With the hind coxal lines closely approaching the midline it keyed very straightforwardly.

Liopterus haemorrhoidalis showing hind coxal lines, North Elmham (Norfolk, UK), 17th September 2024