Purple Emperor
Apatura iris
The Purple Emperor is one of the largest and most striking butterflies in Central Europe, belonging to the Nymphalidae family. Males are famous for the iridescent blue-purple sheen on their upper wings, which is produced by the microscopic structure of the scales rather than pigment. It primarily inhabits moist, semi-natural deciduous forests and is noted for its unusual feeding habits, rarely visiting flowers.
Details
Identification
Dark upper wing surface with white bands and spots; males with blue structural iridescence; distinct orange-ringed eyespot on the hindwing.
Social behavior
Solitary; males gather at exposed treetops for mate location (hilltopping).
Diet
Adults feed on animal droppings, carrion, and tree sap; larvae feed exclusively on willow leaves (especially Salix caprea).
Spawning substrate
Upper surfaces of goat willow leaves (Salix caprea).
Overwintering
Overwinters as an L3 larva attached to the twigs of the host plant (Salix caprea).
Ecology
Ecological role
Specialized herbivore in the larval stage; contributes to the decomposition of organic matter (carrion/dung) as an adult.
Natural predators
Birds, hornets, nursery web spiders, and various ichneumon wasps (parasitoids).
Competitor species
Lesser Purple Emperor (Apatura ilia).
Ecosystem service
Pollination (minor), food source for insectivorous birds.
Threats
Forestry removal of willows, drainage of woodlands, and habitat fragmentation.
Scientific profile
Profile
Distinguishing features
Absence of an eyespot on the upper forewing (distinction from Apatura ilia). The white spot in cell 2 of the forewing is usually absent or reduced. Hindwing features a distinct orange-ringed eyespot near the anal angle.