This large brown butterfly has iridescent wings that shine blue or purple in the light.

Statistics
Wingspan: up to 80mm.

Physical description
The wings are dark brown with white lines and shine iridescently blue and purple. The lower wings have a small orange ring. Purple emperors have a yellow proboscis.

The caterpillars are green, marked with white and yellow, and have two long horns on their heads which make them look a bit like large green slugs. They can be seen lying along the middle of sallow leaves on a bed of silk.

Distribution
They occur throughout central Europe. In Britain purple emperors are confined to the south.

Habitat
They are found in woodlands.

Diet
Purple emperors do not feed from flowers. Instead they feed from honeydew secreted by aphids, and even from dung and rotting animal carcasses. Caterpillars feed on sallow (Salix caprea).

Behaviour
This butterfly is a fast flier. It can often be seen flying early in the morning.

Reproduction
Eggs are laid in late summer and the caterpillars feed on sallow bushes before hibernating.

Conservation status
Purple emperors are scarce and are confined to central southern England. They are not listed as endangered on IUCN Red List 2000.

Records
The largest woodland species of butterfly in Britain.