Nymph identification: 1 to 24 mm in size. The perlodid nymphs D. bicaudata and I. grammatica are separated by the lack of thick covering of black clothing hairs on the body of D. bicaudata.
Mainly stream and river habitats in high altitude (> 200 m) upland area but is known to occur in both high and low attitude in lakes in the west.
The life cycle can be both univoltine & semivoltine. Nymphs are present all year, and adults are in flight from April to June.
Rare and restricted in distribution, especially in the Wicklow Mountains and in the west. Has been recorded from 44 10km squres in Ireland.
Records submitted to Data Centre in 2021
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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.