Small Emperor Moth

Saturnia pavonia — the small emperor moth — is one of about 2,300 species of giant silk moth (family Saturniidae) and the ONLY saturniid native to the British Isles. The species is widespread across temperate and boreal Europe, from Britain east through Scandinavia and into western Asia. Adults are 50-70 mm wingspan; each wing carries a dramatic eye-spot in concentric rings of black, blue, white, and gold. The eye-spots resemble vertebrate eyes and serve as defensive 'flash' coloration to startle bird and small mammal predators. Like all giant silk moths, the adult has no functional mouthparts and lives 4-7 days on caterpillar-stored fat reserves; mating and egg-laying are the only adult tasks. Males and females are dramatically dimorphic: males are 50-60 mm wingspan with brilliant orange hindwings and feathered antennae, capable of long-distance flight in daytime as they search for females; females are 60-70 mm wingspan with pale gray-buff hindwings, less mobile, and tend to stay hidden in vegetation while releasing pheromone. The day-flying behavior of the male is unusual for Saturniidae (most are nocturnal) and is one of the species' most-recognized field characteristics. Caterpillars are bright green with rings of yellow tubercles and feed on heather, bramble, hawthorn, blackthorn, and willow. The species is widespread across heath, moor, woodland edge, and rough grassland habitat.