Green Hairstreak – Callophrys rubi (Stiperstones NNR)

This butterfly is the most widespread of our hairstreaks. However, it is also a local species, forming distinct colonies which can be as small as a few dozen individuals, although other colonies can be much larger. Both sexes always settle with their wings closed, the brown uppersides only ever being seen in flight. The undersides, by contrast, provide the illusion of being green, an effect produced by the diffraction of light on a lattice-like structure found within the wing scales, which provides excellent camouflage as the butterfly rests on a favourite perch, such as a Hawthorn branch. This butterfly will also regulate its body temperature by tilting its wings appropriately to catch the sun’s rays. This butterfly is found throughout the British Isles – partly due to the wide variety of foodplants it uses, and the wide range of habitats it frequents. However, it is absent from the Isle of Man, Outer Hebrides, Orkney and Shetland.