The downy emerald (Cordulia aenea) is a species of dragonfly. It is metallic green and bronze in color, and its thorax is coated with fine hairs, hence its name. Like most other emeralds, the downy emerald has bright shiny green eyes. Adults are around 5 cm in length, and are in flight from May through July each year.This species lives in woodlands near lakes and ponds; like other dragonflies, it lays eggs in water and its larvae are aquatic. It is distributed throughout most of Europe.