Callophrys rubi (Linnaeus, 1758)

Description: Wingspan 27-34mm. A small butterfly which always perches with the wings closed showing the green underside. The underside also has a variable series of white marks. The upperside of both wings is an unmarked rich brown. The sexes are alike.

Similar Species: The Green Hairstreak is unmistakable with its green underside which is always shown when perched. This camouflages the resting adult as it resembles a newly opened leaf. This combined with the small size of the insect mean it can easily be missed.

Key Identification Features:

• Green underside to wings

Sets:

Flight Period: Single brooded from mid-April to late June, peaking in May.

Status: A widespread distribution is indicated in N. Ireland but colonies are very localised. It is absent from much of east Antrim and central Down. It is probably commonest in the Sperrins and the remnant areas of bog in north Armagh.

Ecology: A colonial species found in N. Ireland on bogs and heaths with scrub. Males sit on a perch on a prominent shrub or tree. They adjust their position according to sun direction and temperature. Males leave their perch to investigate passing insects and can lose it when this happens. Any females encountered will be pursued. Females fly over habitat searching for nectar sources or foodplants. Throughout its range the species uses a wide variety of shrubby plants especially ericaceous and leguminous species. In Ireland, probably because of habitat association, it is believed to mainly use bilberry Vaccinium myrtillus and gorse Ulex europaeus. The pupa overwinters.

World Distribution: Throughout Europe, North Africa, Asia Minor and Asia to Siberia.

Bradley & Fletcher number: 1555 Agassiz number: 61.005

Additional information:

UK Butterflies account

Caterpillar: