Description: 5.5-6.2mm black ground beetle with two large, obscure yellow-red spots near the elytral apices. Found on mud at the side of rivers, usually in estuaries. North coast only and rare.

NI account: A great rarity in Ireland and only recorded from localities on or close to the north coast. Johnson & Halbert (1902) cited records for Magilligan, Londonderry (coll. Buckle) and Rathlin Island, Antrim (Hardy 1897). The lakeshore in the Rathlin record has been visited recently, but seems an unlikely habitat, and the species was not re-found. Anderson (in Speight et al., 1983) found a substantial colony on the banks of the River Roe, Londonderry. Refound ther in 2007 by Mark Telfer. Very local in England and Wales, and mainly in the Severn and Humber estuaries (Luff, 1998).

Ecology: On the River Roe the species occupied a sparsely vegetated sandy/silt riverbank subject to some tidal action. On a recent visit to this locality (July 1998) the colony could not be re-found and the habitat had been submerged in 6-10 cm of anoxic clay similar in properties to sewage sludge. Fortunately Mark Telfer refound the species there in 2007.

Distribution: A Eurosiberian Boreo-temperate species (54) distributed from north and west Europe across northern Russia to central Siberia and Mongolia.

Similar Species: Bembidion subg. Peryphus: all other species are either four-spotted or without spots

Key Identification Features:

• Medium-small (4.5-5.5mm)
• Terminal segment of palpi much reduced (Fig. 31)
• Elytral striae disappearing apically and 2nd weaker than 1st
• Pronotum strongly cordate
• Elytra with only two apical spots

Distribution Map from NBN: Bembidion lunatum at National Biodiversity Network mapping facility, data for UK.

iNaturalist: Bembidion lunatum at iNaturalist World Species Observations database.

GBIF data for Bembidion lunatum | Classification: Insecta, Coleoptera, Carabidae, Bembidion

Thumbnails for genus Bembidion