Description: 7-9mm long predatory black ground beetle of vegetated riverbanks and marshland along the coast. Very local.

NI account: Some confusion surrounds the habitat preferences of this species. In Ireland at least, it is primarily an estuarine species and although widespread is very local and usually rare. In Britain its predilection for coastal habitats does not appear to be so marked.

Ecology: Probably exclusively coastal in Ireland, and found on sandy or gravelly, vegetated streambanks and estuaries near the sea. Rare and usually recorded singly.

Distribution: Primarily a Mediterranean-Atlantic species found along coasts from the British Isles south to the Mediterranean and east into Asia Minor, though recorded very rarely from scattered sites in Europe east to Switzerland (Luka et al., 1997) which would denote a Suboceanic Southern-temperate distribution (82).

Similar Species: Agonum afrum: first antennal segment pure black; tibiae and elytral epipleura black A. lugens: upper surface black but dull from strong microsculpture; pronotum with weak denticles at hind angles A. versutum: greatest width of pronotum at or just behind middle, reflexed margins broader - distinct to front angles

Key Identification Features:

• Small, pronotum narrower than elytra, hind angles rounded
• Legs long and slender
• Mentum with median tooth (Fig. 103)
• Claws simple
• Elytral intervals less convex
• First antennal segment dark rufous, tibiae and usually elytral epipleura paler also
• Upper surface shiny black, sometimes slightly bronzed
• Greatest width of pronotum before middle, reflexed margins very narrow, disappearing near front angles
• Meta tarsi with shallow furrows (Fig. 76)

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

iNaturalist: Agonum nigrum at iNaturalist World Species Observations database.

GBIF data for Agonum nigrum | Classification: Insecta, Coleoptera, Carabidae, Agonum

Thumbnails for genus Agonum