Description: A small (2.5-2.7mm) brownish black ground beetle of damp moss, leaf litter, etc, in marshy and heathy places. Mostly in coastal localities but also on montane peat.

NI account: Probably widespread in Ireland but under-recorded. British sites are concentrated in the south-east with only single records for the north of England and Scotland.

Ecology: This species appears to occupy two distinct habitats in Ireland. In the south and east it is mainly recorded from warm, humid, marshy sites beside ponds and pools on the coast, often in partially saline conditions (e.g. at Newtownards, Down). In the north and west there are records for Sphagnum on acid, peaty lakeshores (Derryadd Lough, Armagh) or on raised bog (Garry Bog and The Isles, Antrim).

Distribution: A European temperate species (73) distributed from the British Isles to southern Germany and France, and east to Silesia and the Caucasus.

Similar Species: Acupalpus parvulus: larger (3-4mm); elytra with distinct pale shoulder macula; pronotum much wider than head with more or less pale margins - as exiguus, Fig. 94) (A. exiguus: body darker, nearly black; elytra same shade as forebody; pronotum much wider than head - Fig. 94)

Key Identification Features:

• Very small (2.5-2.8mm), fairly convex and short-legged
• Elytra iridescent
• Pronotum with rounded hind angles
• Elytra with a single setiferous puncture
• Pronotum black to brown, darker than elytra
• Elytra lacking pale shoulder macula
• Pronotum narrow, margins not pale (Fig. 94)

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

iNaturalist: Acupalpus dubius at iNaturalist World Species Observations database.

GBIF data for Acupalpus dubius | Classification: Insecta, Coleoptera, Carabidae, Acupalpus

Thumbnails for genus Acupalpus