Green Hairstreak

Callophrys rubi

Very rare and restricted

Distribution and Status

The Green Hairstreak is rare in the two counties and is mostly found on calcareous grassland such as Hexton Chalk Pit, Aldbury Nowers and the Tring Park area. In the last few years, colonies have been discovered on acid grassland in south-western Middlesex, like Hounslow Heath. It does not appear to exist in open areas in woodland like it did in the past

Habitat Requirements

Unimproved grassland, railway banks, and woodland rides but scrubby plants or hedgerows must be present

Larval Foodplants

Common Rock-rose Helianthemum nummularium, Broom Cytisus scoparius, Dyer's Greenweed Genista tinctoria, Gorse Ulex spp., Common Bird's-foot Trefoil Lotus corniculatus on chalk. Other foodplants used include Greater Bird's-foot Trefoil L. pedunculatus, Dogwood Cornus sanguinea, Buckthorn Rhamnus catharticus and Bramble Rubus fruticosus

Adult Food Sources

Goat Willow Salix cinerea, Bluebell Hyacinthoides non-scripta, Common Bird's-foot Trefoil Lotus corniculatus, Hawkweed Hieracium sp. and Hawthorn Crataegus monogyna

Behaviour/Observation notes

Males take up territories around shrubs like hawthorn, in search for females or to chase off rival males. Females tend to fly close to the ground

Life History

Only one generation is produced each year with most specimens emerging in May. Eggs are laid singly on the foodplant and hatch after about ten days. Larvae begin by feeding in buds then the leaves as they grow. Pupae are formed on the ground, often in ants' nests. The ants being attracted by the pupae are thought to carry them to the nests. The winter is spent in the pupal stage

Further information

More on life cycle and status
UK distribution map
Full list of larval hostplants and adult food sources on Peter Hardy's database
Stevenage butterflies - additional notes