Description: A small (7.5-10mm) brownish or piceous-black ground beetle. Rare and very local in Ireland in wooded fens or peaty upland woods.

NI account: Widely distributed in southern Britain but much rarer in the north (Luff, 1998). Unaccountably rare in Ireland. Widespread peaty conditions in the mid Postglacial may have favoured P. assimilis which occurred at lower altitudes than it does today (Anderson, 1989). Early Irish records are generally uncertain due to confusion with P. assimilis and although Johnson & Halbert (1902) quote a number of upland sites in Donegal, Antrim, Down, Dublin and Kerry, these probably relate to assimilis rather than atrorufus. The only definite records we have are for a wooded (deciduous) fen at Edenderry west of Belfast (Speight et al., 1983), and for a Sitka spruce plantation at Springwell in Londonderry (Day & Carthy, 1988).

Ecology: In lowland northern Europe, this species is often recorded by pitfall-trapping of arable areas (Tolonen, 1995). It is primarily a species of humid forest ecotopes, at least in Fennoscandia (Lindroth, 1985). However it is regarded as cold-preferent in central Europe where it inhabits subalpine woods and heath in places where P. assimilis is absent (Marggi, 1992). In some northern or upland habitats there is an implied overlap in habitat preferences with P. assimilis and possibly a degree of competition. The two do not appear to occur together in Fennoscandia, although Houston & Luff (1983) suggest a degree of co-existence in some British habitats.

Distribution: A Eurosiberian Boreo-temperate species (54) distributed from southern and eastern Fennoscandia south to northern France and north Italy and eastwards to west Siberia. Introduced to North America.

Similar Species: Patrobus assimilis:small (<9mm), dark; frontal furrows parallel (Fig. 30); foreparts (including head) transversely wrinkled

Key Identification Features:

• Size 7.5-10mm
• Brown or red-brown in colour
• Neck constricted behind eyes and with a lace
• Frontal furrows deep
• Frontal furrows forwardly diverging (Fig. 29)
• Foreparts smooth

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

iNaturalist: Patrobus atrorufus at iNaturalist World Species Observations database.

GBIF data for Patrobus atrorufus | Classification: Insecta, Coleoptera, Carabidae, Patrobus

Thumbnails for genus Patrobus