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
Formerly widespread in southern England but it has become increasingly scarce in recent years.
Found at Portscatho (Champion, 1897) and The Lizard in 1972 (Allen, 1973).
Habitat & Ecology
Feeds on larvae of Phaedon spp. of leaf beetle, especially those on Water-cress Rorippa nasturtium-aquaticum .
Pollution of water courses; loss of stock access leading to coarsening of vegetation.
Protection of unpolluted water courses which have good stands of Water-cress.
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.