The Green Hairstreak (Callophrys rubi) is a small butterfly, which is still widespread across most of the UK, although many colonies have been lost in recent years. The upperside is a uniform dull brown with two paler patches on the male's forewings made up of scent scales. The undersides are a bright green with a thin white line, often reduced to a faint row of dots or even missing altogether. They never rest with their wings open.
It has what is probably one of the largest range of foodplants of any British butterfly. Early butterfly collectors thought that the only foodplant was Bramble (blackberry) Rubus fruticosus hence its scientific name, but as its habits became better understood the list grew and will probably continue to do so. Depending on the habitat it will also use Common Rock Rose Helianthemum nummularium, Bird's-foot trefoil Lotus corniculatus, Gorse Ulex europaeus, Broom Cytisus scoparius, Dyer's Greenweed Genista tinctoria, Bilberry Vaccinium myrtillus, Dogwood Cornus sanguinea, Buckthorn Rhamnus cathartica, Cross-leaved Heath Erica tetralix.
This range of foodplants means that it is able to use a range of habitats including chalk downland, heathland, moorland and woodland. The eggs are laid singly and the caterpillars are green with yellow markings along the back. Like other members of the family they are rather sluglike. They are not known to be tended by ants like some lycid larvae but the pupae, which are formed at ground level, emit squeaks which attract ants and it is thought that ants will always bury any that are found. Green Hairstreaks overwinter as pupae and have one brood a year.
Text and photograph courtesy of Wikipedia.