How do you tell a moth from a butterfly? Not a joke, a serious question! Answer? Moths have feathered antennae where as a butterfly has clubbed antennae.
A look at this photo will quickly tell you then that with those lovely, long, feathered antennae that this is a moth. In fact, that makes this a male moth. They use those antennae to pick up the scent of female pheromones up to 200 yards away.
The oak beauty Biston strataria is a distinctive species, bulky with grey and black markings on the forewings. It is a resident species, nocturnL, single brooded and pretty hardy; it flies early in the year, usually in March and April. It is widespread and not uncommon in woodlands and parkland in England, especially in the south.
Eggs are laid on a range of trees including oak, hazel and alder. The larvae emerge in May and pupate in July and over winter in that state before being one of earliest species to emerge.