Mayflies are found in rivers and lakes thoughout Ireland. The name is misleading: one species the very large and conspicuous Green Drake Mayfly (Ephemera danica) appears on lakes and rivers in May around the time that hawthorn is in bloom, but there are many other smaller species that can be seen thoughout the year. In the Maigue catchment rivers, the Large Dark Olive mayfly (Baetis rhodani) is the first to appear as an adult in February, followed by the Small Dark Olive, Iron Blue, Medium Olive, Green Drake, Yellow May Dun, Fisherman’s Curse and Blue-Winged Olive. Mayflies have a complex life cycle, which involves a larval stage that lives on the river or lake bed for one or more years, and a short-lived, winged, adult stage in which mating and egg-laying takes place. The adult flies are generally olive to yellowish in colour and have a pair of large wings and a pair of smaller wings.