Ephemera danica
Ephemera danica, the green drake or green drake mayfly, is a species of mayfly in the genus Ephemera.
Description
Ephemera danica can reach an imago size of in males, while females are larger, reaching. This mayfly, with its characteristic markings and three tails, is the most commonly seen of British Ephemeridae. Imago wings are translucent with dark veining, while in subimago they are dull and yellowish with brown veins. Moreover, forelegs and the tails of the spinners are much longer than in duns. Mouthparts are non-functional, as adults do not feed.These insects are aeroplankton and usually are food for swallows, trout and various species of amphibians and spiders.
Life cycle
The life cycle usually lasts one or two years, but sometimes the developing nymphal forms may last for up to three years. Nymphs can reach a length of about. They dig tunnels into the gravel in the beds of rivers and feed by filtering organic detritus, before emerging in spring and moving towards shallow waters.The adults mainly can be found in May–June, at the end of many larval stages. Adults may be often present between April and November. The lifetime of adults is very short, hence its genus name.
Females fly on the surface of the water and dip their abdomen onto the surface to lay eggs. At the end of this process, females fall onto the surface of the water and die.