The descriptive text, below the map, is from the Cornish Red Data Book (2009). The map on this web page depicts the organisms distribution and shows the records made pre-2000 and those made since.
Range & Status
The species is relatively common in southern England and Wales and there are indications that the range may be increasing. It has benefited from the increase in flooded gravel pits in the early stages of bank-side succession.
In the 1997 edition of the Red Data Book, the species was noted as having strong
populations on the Lizard Peninsula and the china clay areas around St. Austell. The population has expanded and Caradon has developed good numbers at Bake Lakes, Siblyback Reservoir, Dozmary Pool and, most recently, Park Pit on the southern boundary of Bodmin Moor.
Habitat & Ecology
The species favours pools, lakes and very slow moving water with exposed marginal areas with bare, trampled ground or stones.
Males of the species require bare ground to perch; as succession of vegetation occurs, the species becomes less abundant.
The species is thriving and is in a stronger position than 1997. Consistent recording will ensure the status of the species in Cornwall is understood.
I.J. Bennallick, S. Board, C.N. French, P.A. Gainey, C. Neil, R. Parslow, A. Spalding and P.E. Tompsett. eds. 2009. Red Data Book for Cornwall and the Isles of Scilly. 2nd Edition.Croceago Press.
The Cornish Red Data Book Project was led by the Cornwall and Isles of Scilly Federation for Biological Recorders (CISFBR). The full text and species accounts (minus the maps) are available on the CISFBR website.