Invertebrates
Purple Hairstreak
Favonius quercus
High in an old oak on a July evening, a tiny purple hairstreak drops from the leaves to catch the last of the sun, its wings flashing a violet sheen for a moment before it disappears again.
Overview
The purple hairstreak, Favonius quercus, is a Least Concern butterfly of oak woodland across Europe, reaching North Africa and Turkey. Its secretive life in the treetops, purple sheen, and diet of aphid honeydew make it one of the least-seen but most widespread butterflies in European woods.
A butterfly of the treetops
Because it rarely comes down from the oak canopy, the purple hairstreak is far more common than most people realise, and is best looked for with binoculars on warm summer evenings.
Status
Least Concern, widespread but under-recorded.
Purple Hairstreak: common questions
Where does the purple hairstreak live?
It lives high in the canopy of oak trees, so it is often overlooked even where it is common.
What does the purple hairstreak eat?
Adults feed mainly on honeydew from aphids on oak leaves, while the caterpillars eat oak buds and young leaves.
How does it survive the winter?
It overwinters as an egg, laid on an oak twig near a bud and hatching in spring as the leaves open.
Is the purple hairstreak related to the great purple hairstreak?
Both are hairstreak butterflies, but the great purple hairstreak is a different species that lives in the southern United States and feeds on mistletoe.