Description: A small (6-8mm), black ground beetle which is widespread and common in damp, heavily vegetated water margins, especially in beds of common reed, Phragmites, or reedmace, Typha. Two colour forms occur, the uniformly dark puellum and thoreyi, with paler, brownish, elytra, pale limbs and pale first antennal segment.

NI account: Like the previous species prefers well-vegetated water margin biotopes but more associated with lakeshores than with fens. Nearly always gregarious and common where it occurs.

Ecology: Recorded from a wide range of vegetated, eutrophic lakeshores and riverbanks; also swamps and fens. Not recorded from ombrotrophic mires. Often found hibernating in hollow Phragmites stems on lakeshores.

Distribution: A Eurasian Wide-temperate species (65) found across Europe except the south, and eastwards into Siberia as far as the River Amur. Introduced in North America.

Similar Species: Agonum fuliginosum: tarsi without furrows Agonum gracile: tarsi without furrows; upper surface uniformly black

Key Identification Features:

• Medium, pronotum narrower than elytra, hind angles rounded
• Legs long and slender
• Mentum with median tooth (Fig. 103)
• Claws simple
• Third antennal segment pubescent, at least apically
• All tarsal segments with a median furrow
• Two colour forms, one uniformly dark, the other with pale appendages and brown elytra

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

iNaturalist: Agonum thoreyi at iNaturalist World Species Observations database.

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

Thumbnails for genus Agonum