Leuctra fusca


Species Biology


Nymph identification: 0.5 to 10 mm in size. The separation of the four leuctrid species in Ireland may cause some identification problems, but L. fusca has a fine fringe of hairs on it's tibia. Careful illumination of the tibia under a stereo microscope and the use of a black or dark background make the identification of this species much easier.


Streams and rivers with fine or course gravel, cobbles and boulder habitats, but also amongst mosses, macrophytes and organic matter.

Life cycle

Univoltine - produces one brood in a year. Adult flight period is from June to December. Nymphs present from February to August.


World distribution(GBIF)

Irish distribution

Common and widespread throughtout the country. Has been recorded from 186 10 km squares in Ireland.

Temporal change

Records submitted to Data Centre in 2023

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H.B. Feeley, J-R. Baars & M. Kelly-Quinn (2016) The Stonefly (Plecoptera) of Ireland –
Distribution, Life Histories & Ecology
. National Biodiversity Data Centre, Waterford. Ireland.