Best time to see: Apr to mid Jun
Key facts
A large butterfly with clear yellow wings, looking like a pale yellow leaf when perched with its wings closed
Habitat: woods, hedgerows and scrubby areas
Common in southern England and south Wales
Recognition
Clear yellow wings, paler in the female, and yellow body, with pink antennae; wingspan 60mm
Adults hibernate and emerge in spring, wander freely looking for mates and for buckthorn bushes to lay eggs
Young emerge in August and gorge themselves on nectar, preparing for hibernation
Lifecycle
Eggs are bottle-shaped and off-white, laid singly on the tips of branches of bushes of Purging or Alder Buckthorn
Caterpillars, bluish-green with a white stripe, hatch in June or early July, turning into a chrysalis in late July or early August
Adults emerge in August then feed through autumn ready for hibernation, re-emerging on the first warm days of spring
© Ken Wooldridge
© David Corke