Emperor Moth
Saturnia pavonia
Tap image to enlarge · Wikimedia Commons
Overview
Britain's only wild silk moth, the Emperor is spectacular. Males fly in afternoon sunshine in April, using their extraordinary feathery antennae to detect female pheromones from over a kilometre away. The large eye spots on all four wings are dramatic. Females are nocturnal. The caterpillars are vivid green with pink and black spots, feeding on Heather and Bramble. The Sefton Coast's dune heath is one of the better places to see this species in northwest England.
At a Glance
| Order | Lepidoptera |
| Family | Saturniidae |
| Habitat | Dune heath · Heather heath · Moorland edge |
| Diet | Adults: do not feed. Larvae: Heather, Bramble, Hawthorn, Blackthorn |
| UK population | Widespread on heathland and moorland; declining due to heathland loss |
| Sefton Coast | Present in the heather areas at Ainsdale NNR; one of the better northwest England sites |
| Conservation | UK Green List |
Where to See It
Dune heath and heather areas at Ainsdale NNR. Males fly fast along heather edges in afternoon sunshine.
Identification
Large moth. Males: orange-brown with large eye spots on all four wings, fly in daylight. Females: grey with same eye spots, nocturnal. Feathery comb-like antennae on males. Wingspan to 85mm.
Viewing & Photography Tips
Walk the heather areas at Ainsdale on a warm, sunny April afternoon. Males fly fast, low over the heather in a zig-zagging searching flight. They can be attracted by a caged female if you know someone who breeds them.
Conservation Status
UK Green List
This species has a favourable conservation status in the UK and remains an important part of Sefton Coast biodiversity.
Frequently Asked Questions
How do male Emperor Moths find females?
Male Emperor Moths have extremely large, feathery (bipectinate) antennae that can detect female pheromones at concentrations as low as a few molecules per cubic metre. Males can locate a female from over a kilometre downwind. This is why male Emperor Moths fly rapidly in a searching pattern — they are following a pheromone plume back to its source.
Plan your visit to the Sefton Coast
Marshside RSPB, Formby pinewoods, Ainsdale NNR — practical guides to getting there, what to bring, and the best spots for each season.