Bledius annularis

LeConte, 1863

ringed borrow rove beetle

Bledius annularis is a small spiny-legged rove beetle in the Staphylinidae, found across northern North America. The measures 3.8–4.5 mm and exhibits distinctive coloration with a black and contrasting with reddish-brown and abdominal base. It belongs to the taxonomically challenging "annularis complex" of closely related Bledius species that are difficult to distinguish morphologically.

Pronunciation

How to pronounce Bledius annularis: /ˈbleː.di.us ænˈnuː.la.ris/

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Identification

Most reliably distinguished from other Bledius by the combination of: black and with reddish-brown and abdominal base, black abdominal tip, and dark yellow legs. Part of the "annularis complex" (including B. breretoni, B. honestus, B. languidus, B. mysticus, B. nebulosus, B. sinuatus, B. stabilis, and B. washingtonensis), which contains morphologically similar species requiring expert examination for definitive identification. The faintly banded abdominal appearance caused by darker segment margins can aid recognition.

Appearance

Slender, elongate body measuring 3.8–4.5 mm in length. and black; , antennal bases, and abdominal base reddish-brown; abdominal tip black; legs dark yellow. Head lightly granulate and finely punctate. Thorax longer than wide. Abdominal base narrower than elytra. sometimes appears faintly banded due to slightly darker hind margins of segments.

Habitat

Damp clay riverbanks and shaded streams. In New Brunswick, characteristically associated with these riparian microhabitats.

Distribution

Northern North America. Recorded from Canada (Alberta, British Columbia, Manitoba, New Brunswick, Newfoundland and Labrador, Nova Scotia, Northwest Territories, Ontario, Quebec, Saskatchewan, Yukon) and USA (Alaska, District of Columbia, Idaho, Indiana, Maine, New Hampshire, New York, Oregon, Washington).

Similar Taxa

  • Bledius breretoniMember of annularis complex; morphologically similar, requires expert identification
  • Bledius honestusMember of annularis complex; morphologically similar, requires expert identification
  • Bledius languidusMember of annularis complex; morphologically similar, requires expert identification
  • Bledius mysticusMember of annularis complex; morphologically similar, requires expert identification
  • Bledius nebulosusMember of annularis complex; morphologically similar, requires expert identification
  • Bledius sinuatusMember of annularis complex; morphologically similar, requires expert identification
  • Bledius stabilisMember of annularis complex; morphologically similar, requires expert identification
  • Bledius washingtonensisMember of annularis complex; morphologically similar, requires expert identification

More Details

Type specimen

Lectotype designated from male specimen collected from Lake Superior, housed at the Museum of Comparative Zoology, Harvard University

Taxonomic complexity

The annularis complex represents a group of at least nine closely related Bledius distributed across northern North America that are difficult to distinguish; B. annularis is part of the 'annularis group' subdivision within this complex

Sources and further reading