Commonly known as Yellow May, this species are known as stone-clingers in their nymph form with 6 elbowed legs and distinct patterning of light and dark patches on the legs. The nymphs are common amongst Spate Rivers (rivers that rise and fall according to rainfall and often have hard solid bedrock with scarce soluble minerals, making them infertile). They are less common amongst chalk streams. They are abundant in the Spate Rivers in Wales. Yellow May are common and widespread across the British Isles.