Invertebrates
Purple Emperor
Apatura iris · also called His Majesty
High in the crown of an oak on a July morning, a male purple emperor turns his wings to the light and flashes a brilliant violet-blue, then glides away into the leaves.
Overview
The purple emperor, Apatura iris, is a Least Concern butterfly of mature broadleaved woodland across Europe and western Asia. Its iridescent males, treetop life, and unusual diet of sap and honeydew make it one of the most sought-after and elusive butterflies in Europe.
A butterfly of the canopy
Because the purple emperor lives in the treetops and rarely comes to flowers, many people never see one, which only adds to its mystique.
Status
Least Concern, widespread but thinly spread.
Purple Emperor: common questions
Why is it called the purple emperor?
Males show a flash of iridescent purple-blue on the upper wings, and the butterfly is large and regal in the treetops.
What does the purple emperor eat?
As an adult it feeds on tree sap, aphid honeydew, and sometimes mud, dung, or carrion, rather than flower nectar.
Why is the purple emperor so hard to see?
It spends most of its time high in the treetops of broadleaved woodland and rarely visits flowers.
What do purple emperor caterpillars eat?
They feed on the leaves of sallow, or goat willow.