This list of mayflies of the British Isles follows Macadam, [1] with nomenclature and taxonomy according to Kluge. [2] There are 51 species of mayfly known to occur in the British Isles
The following genera and species have been recorded: from ten families.
Baetidae is a family of mayflies with about 1000 described species in 110 genera distributed worldwide. These are among the smallest of mayflies, adults rarely exceeding 10 mm in length excluding the two long slender tails and sometimes much smaller, and members of the family are often referred to as small mayflies or small minnow mayflies. Most species have long oval forewings with very few cross veins but the hindwings are usually very small or even absent. The males often have very large eyes, shaped like turrets above the head.
Caenidae, is a family of mayflies, sometimes called "small squaregill mayflies". Species are found throughout the world in lotic, depositional environments, and they are sprawlers. Caenids occur in quiet and even stagnant water and are often overlooked because they are so small. They like to live in silty bottoms, and their gills are specially adapted for such environments.
Leptophlebiidae is a family belonging to the Ephemeropterans that are commonly known as the prong-gilled mayflies or leptophlebiids. It is the only family in the superfamily Leptophlebioidea. There are more than 650 described species of Leptophlebiids, which are easily recognized by the forked gills present on the larvae's abdomen, thus their common name.
Caenis is a genus of mayflies. They are very small in size, sometimes with a body of only an 1/8 of an inch (3.2 mm).
Baetis is a genus of mayflies of the family Baetidae, known as the blue-winged olive to anglers. There are at least 150 described species in Baetis. They are distributed worldwide, with the most variety in North America and northern Europe.
Cloeon is a cosmopolitan genus of mayflies of the family Baetidae.
Labiobaetis is a genus of mayflies in the family Baetidae.
Paraleptophlebia is a genus of mayflies in the family Leptophlebiidae. Commonly found in North America and parts of Western Europe including the British Isles.
Cloeon dipterum is a species of mayfly with a Holarctic distribution. It is the most common mayfly in ponds in the British Isles and the only ovoviviparous mayfly in Europe. Males differ from females in having turbinate eyes.
In the 10th edition of Systema Naturae, Carl Linnaeus classified the arthropods, including insects, arachnids and crustaceans, among his class "Insecta". Insects with net-veined wings were brought together under the name Neuroptera.
Nigrobaetis is a genus of small minnow mayflies in the family Baetidae. There are more than 30 described species in Nigrobaetis, found in Europe, Africa, and Asia.