Invertebrates
Holly Blue
Celastrina argiolus · also called holly blue butterfly
Fluttering around the top of a garden hedge in April, a holly blue flashes pale silvery-blue, a butterfly whose spring brood lays on holly flowers and whose summer brood moves on to ivy.
Overview
The holly blue, Celastrina argiolus, is a Least Concern butterfly of hedgerows, gardens, and woodland edges across Europe, North Africa, and temperate Asia. Its two-brood, two-food-plant life cycle and high, fluttering flight make it one of the most distinctive blues.
A butterfly that switches plants
By using holly in spring and ivy in summer, the holly blue makes the most of two plants that flower at different times.
Status
Least Concern, widespread, with numbers that vary from year to year.
Holly Blue: common questions
Why is it called the holly blue?
The spring brood lays its eggs on holly, while the summer brood lays on ivy.
Does the holly blue have orange spots?
No, its silvery-blue underside is spotted with tiny black dots and has no orange markings.
How does the holly blue spend the winter?
It spends the winter as a chrysalis, hidden in a sheltered spot.
Where is the holly blue found?
It lives in hedgerows, gardens, and woodland edges across Europe, North Africa, and temperate Asia.