Apatura iris
The Purple Emperor is the largest of our woodland butterflies but away from the well-known Sussex hotspots it is generally an elusive species, and therefore difficult to locate and obtain good views. Only the male is purple, but the light conditions and the angle of the sun must be just right for the exotic colours to be fully appreciated and in dull light it may appear black or dark brown. The female is larger than the male and is a rich, dark brown. The only possible confusion species is White Admiral, but the latter is much smaller and has rounded, not pointed wings. White Admirals also have a different flight profile, which is often described as 'graceful and flitting', compared to the much larger, more powerful Purple Emperor which habitually glides for long periods, with short flicks of the wings to sustain these glides.
The first adults emerge between June 16th and June 23rd, and they continue to emerge over the following three weeks or so. The total flight period is relatively short and by early August their season is more-or-less over. Most colonies are quite small and are often scattered over many neighbouring woods and copses. Within each complex of woods, there are one or more 'Master Trees', which in Sussex is usually a cluster of Oak trees.
Once mated the females look for suitable sallows on which to lay their eggs. Goat Willow is preferred but Grey Willow and various hybrids may be used.
Purple Emperors can be found throughout most of West Sussex but in East Sussex it is largely confined to the west and north of the vice county. Until fairly recently, Sussex butterfly enthusiasts flocked to the Southwater Woods complex of woods to observe and photograph Purple Emperors but its premier position has been usurped by the Knepp Estate, which is now the best site in the UK to see this species!
Knepp Castle Estate TQ134193 to TQ14213; Southwater Woods TQ131257 to TQ140254; Eartham Wood to Bignor Hill SU940105 to SU970128; Houghton Forest SU997105 to SU995112; West Grinstead Downs Link TQ183225 to TQ173245.
Female in vegetation – photo by Neil Hulme
Male on the ground, with open wings – photo by Kirsty Gibbs
Male on the ground, with closed wings – photo by Kirsty Gibbs
Male on vegetation – photo by Dave Brown
Female on the ground, taking in salts and minerals – Photo by Derek Barber
Female in Oak canopy – photo by David Cook
Butterfly Conservation Purple Emperor
