Dyschirius obscurus (Gyllenhal, 1827)

Description: Small (3.5-4.5mm) dull bronze-black fossorial ground beetle, confined to bare sand on Lough Neagh in Ireland. Usually associated with Bledius subterraneus in its Irish habitats.

NI account: Confined to the shores of Lough Neagh where it was first found by Haliday (Dawson 1854). Several adventitious colonies have recently been recorded in gravel pits in south-east England, having come in from Europe. Unknown elsewhere in the British Isles.

Ecology: Stenotopic for fine sand habitats which are stabilised by moisture. In this respect its requirements are similar to those of D. impunctipennis, although the ranges of the two do not overlap in Ireland. On Lough Neagh the usual oxyteline associate is Bledius subterraneus Erichson, but it has also been found with Bledius fuscipes agg. (Anderson, 1979). A recent survey of Lough Neagh habitats has indicated that association of D. obscurus with Bledius is not obligatory. Colonies of Bledius spp. were found on only six beaches out of a total of sixteen on which large populations of D. obscurus were present (R. Anderson unpublished). Some flexibility with regard to food preferences seems likely in these circumstances. An obligatory reliance on Bledius is discounted by Thiele (1977).

Distribution: A European, or possibly Eurosiberian, Boreo-temperate species (53), scattered over north, west and central Europe to the Caspian Sea, but mostly near sea coasts.

Similar Species: Dyschirius thoracicus: elytral striae punctate; upper surface shiny; coastal

Key Identification Features:

  • Brassy, elongate, cylindrical and with a 'waist'
  • Fore legs adapted for digging
  • Clypeus with a median tooth (Fig. 28)
  • Elytral striae smooth or nearly so
  • Upper surface with at least pronotum dull from micro-reticulation
  • Lough Neagh only

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

iNaturalist: Dyschirius obscurus at iNaturalist World Species Observations database.

GBIF data for Dyschirius obscurus | Classification: Insecta, Coleoptera, Carabidae, Dyschirius

Thumbnails for genus Dyschirius

 Anderson, R., 2024. Dyschirius obscurus. (Gyllenhal, 1827). [In] Ground Beetles of Ireland.
https://www2.habitas.org.uk/beetles/species.php?item=7179. Accessed on 2024-12-27.