Rare medium stonefly
The Rare medium stonefly is one of the eight rare and threatened riverflies which have been designated as conservation priorities by the UK Government and are listed on the UK Biodiversity Action Plan (BAP). This webpage gives details of the Rare medium stonefly and has links to more detailed documents.
Rare medium stonefly (Isogenus nubecula)
This stonefly occurs only on the river Dee in Wales and was last found in 1995, unfortunately the species wasn't found during recent surveys and may now be extinct. This stonefly likes large stony lowland streams with bankside trees and vegetation and is likely to emerge from the water and fly between March and April. Threats to this species include pollution (industrial and agricultural); poaching of riverbanks and channel by livestock; unsympathetic engineering works; bankside lighting; it is also vulnerable to floods and droughts because it is so rare.
To see the Rare medium stonefly (Isogenus nubecula) Species Dossier click here.
To see the Rare medium stonefly (Isogenus nubecula) Summary Sheet click here (for the Welsh version click here).
To find out more about the Riverfly Partnership and the Riverfly BAP Project click here.
