Description: A pubescent, moderate-sized (10-12.5mm) metallic copper and green ground beetle found in marshes and reedbeds. Mainly on limestone, southern and western.

NI account: Johnson & Halbert (1902) regarded this species as common on riverbanks and lakeshores throughout Ireland, and included "Antrim (Rathlin to Belfast), Down, Armagh, Fermanagh" within its range. Today it is restricted mainly to Fermanagh in the northern counties and, though widespread, is possibly less common than formerly in southern counties also.

Ecology: Largely riparian on the margins of eutrophic lakes and sluggish rivers in Ireland, and nowadays mainly in limestone areas of the west. Sometimes encountered running on open ground in bright sunshine.

Distribution: A Eurosiberian Wide-temperate species (64) distributed from western and northern Europe to eastern Siberia.

Similar Species: Chlaenius tristis: all antennal segments, including first, dark; much darker and generally lacking the bright metallic reflections on pronotum and elytra; pronotum broader in front (Fig. 89)

Key Identification Features:

• Medium to large
• Entire upper surface punctate and pubescent
• Elytra without setiferous punctures
• Upper surface metallic, variable, usually with forebody bronze or reddish, elytra green
• First antennal segment usually pale but dark in some Irish specimens

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

iNaturalist: Chlaenius nigricornis at iNaturalist World Species Observations database.

GBIF data for Chlaenius nigricornis | Classification: Insecta, Coleoptera, Carabidae, Chlaenius

Thumbnails for genus Chlaenius