Holly blue Celastrina argiolus

The holly blue is widespread throughout southern England though its range has been extending northwards. It can be seen in open woods and along hedgerows as well as churchyards where there is both holly and ivy and it is a frequent visitor to gardens.

Conservation status

The species goes through boom and bust population cycles so it can be difficult to tell whether it is doing well. However, national statistics demonstrate a significant increase in distribution and numbers. From 1976-2004 the population was up by 280% and the area covered by 36% (The State of Butterflies in Britain and Ireland – 2006). In Norfolk, the tetrad occupancy increased from 192 in the 1980s to 475 in the 1990s and 580 in 2001-2010 (30 Years of Norfolk Butterflies).

Details

Did you know? The caterpillar has two distinct foodplants. In the spring they feed on the flower buds of holly and, in late summer, switch to ivy.

Holly blues tend to fly higher than other members of the blue family; a blue butterfly passing at shoulder/head height is almost certain to be a holly blue.

How to recognise

Where to see

When to see

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