Leptophlebiidae (Ephemeroptera) of the alpine region of the Southern Alps, New Zealand

The alpine region of the South Island of New Zealand is the habitat of a group of endemic mayfly Species Of the genus Deleatidium, which show adaptation to an alpine tundra a environment. Their speciation may be best explained as the consequence of a series of Pleistocene ice advances and retreats. The larval stages of these species are well adapted to cold, fast water and high levels of ultraviolet radiation. Their distribution, restricted by geographic and climatic factors, renders the group vulnerable to climate change.