Scientific name: Celastrina argiolus
A widespread butterfly often found in parks and gardens.
Wings are bright blue. Females have black wing edges. Undersides pale blue with small black spots which distinguish them from Common Blue.
The Holly Blue is easily identified in early spring, as it emerges well before other blue butterflies. It tends to fly high around bushes and trees, whereas other grassland blues usually stay near ground level. It is much the commonest blue found in parks and gardens where it congregates around Holly (in spring) and Ivy (in late summer).
The Holly Blue is widespread, but undergoes large fluctuations in numbers from year to year. It has expanded northwards in recent years and has colonised parts of midland and northern England.
Size and Family
- Family: Blues
- Size: Small
- Wing Span Range (male to female): 35mm
- Butterfly Conservation priority: Low
- European status: Not threatened
- Fully Protected under the Northern Ireland 1985 Wildlife Order
The larvae feed predominantly on the flower buds, berries and terminal leaves of Holly (Ilex aquifolium) in the spring generation, and Ivy (Hedera helix) in the summer generation. The spring generation can complete larval development entirely on leaves of male Holly bushes, although female bushes are preferred. They also use a wide range of other wild and garden plants including Spindle (Euonymus europaeus), dogwoods (Cornus spp.), snowberries (Symphoricarpos spp), gorses (Ulex spp.), and Bramble (Rubus fruticosus).
A common garden visitor, also seen in parks, churchyards, hedgerows and woodland rides.
- Countries: England, Ireland, Scotland and Wales
- Widespread in England and Wales, rarer in Ireland
- Distribution Trend Since 1970’s = +36%