List of Ephemeropterans of Sri Lanka

Phylum: Arthropoda
Class: Insecta
Order: Ephemeroptera

Mayflies or shadflies are aquatic insects belonging to the order Ephemeroptera. Over 3,000 species of mayfly are known worldwide, grouped into over 400 genera in 42 families.

Mayflies are relatively primitive insects and exhibit a number of ancestral traits that were probably present in the first flying insects, such as long tails and wings that do not fold flat over the abdomen. They are aquatic insects whose immature stages (called "naiads" or "nymphs") live in fresh water, where their presence indicates a clean, unpolluted environment. They are unique among insect orders in having a fully winged terrestrial adult stage, the subimago, which moults into a sexually mature adult, the imago.

In 1853, Walker first described about two species of mayflies from Sri Lanka. Then 1858, Hagen documented 8 more species from the country. The most useful taxonomic and other ecological aspects of mayflies of Sri Lanka came during 1960s and 1970s by Peters (1967) and Peters & Edmunds (1970). In 1965, Fernando described comprehensive work on mayflies.[1] Through this, Hubbard and co-workers documented 46 species in 8 families from the country which is the most valuable source for present day as well.[2] Currently there are 52 species of mayflies are reported from Sri Lanka, which belongs to 8 families.[3]