Tawny Prominent Harpyia milhauseri
Wingspan 50-60 mm.
A very rare visitor to the British Isles from continental Europe, there have been only two records of this species; in 1966 in West Sussex and 1993 in Kent.
Abroad, the species flies between May and July, occupying wooded habitats.
The caterpillar has not been found in Britain, but elsewhere feeds on oak (Quercus) and beech (Fagus).