Holly Blue

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

Conservation Status

GB Red List (2022): Least Concern
Butterfly Conservation priority: Low
European status: Not threatened
Fully Protected under the Northern Ireland 1985 Wildlife Order

Caterpillar Foodplants

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).