Green Hairstreak

Callophrys rubi has a wingspan reaching about 26–30 millimetres. The upperside of the wings 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. The iridescent green colour of the undersides is a structural colour caused by diffraction and interference of light by microscopic repeating structures in the wing scales. The caterpillars are green with yellow markings along the back.