Description: A moderately large (8.5 - 11.5 mm) dull, dark-brown species with pale appendages. Similar to Calathus erratus but broader and with the pronotum broadest behind the middle and with translucent margins.

NI account: Erroneously recorded by several authors for coastal localities in Ireland but discounted by Johnson & Halbert (1902). A single female was collected under driftwood on fore dunes at Ballyteigue Burrows by Tony Murray on 30 April 2009 (Anderson & Murray, 2010).

Ecology: Thermophilic on south-facing sparsely vegetated slopes or on coastal dunes.

Distribution: Found across Europe to 60°N. Distribution Eurasian Wide-temperate (65).

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

iNaturalist: Calathus ambiguus at iNaturalist World Species Observations database.

GBIF data for Calathus ambiguus | Classification: Insecta, Coleoptera, Carabidae, Calathus

Thumbnails for genus Calathus