Dinaraea bicornis Klimaszewski & Webster

Klimaszewski, Jan, Webster, Reginald P., Langor, David W., Caroline Bourdon, & Jacobs, Jenna, 2013, Review of Canadian species of the genus Dinaraea Thomson, with descriptions of six new species (Coleoptera, Staphylinidae, Aleocharinae, Athetini), ZooKeys 327, pp. 65-101 : 69-71

1. Dinaraea bicornis Klimaszewski & Webster sp. n. Fig. 1 a–g, Map 1

HOLOTYPE

(male): CANADA, NEW BRUNSWICK, York Co., Kingsclear, Mazerolle Settlement, 45.872288°N, 66.83105°W, 9.IV.2006, R.P. Webster // Margin of stream, in litter at base of northern white cedar (LFC). PARATYPES: CANADA, NEW BRUNSWICK: Charlotte Co., 5 km NW of Pomeroy Ridge, 45.3059°N, 67.4343°W, 5.VI.2008, R.P. Webster // Red maple and eastern white cedar swamp, in moss & leaf litter near small vernal pools (RWC) 1 male; Charlotte Co., 3.5 km NW of Pomeroy Ridge, 45.3087°N, 67.4362°W, 16.VI.2008, R.P. Webster // Red maple swamp, in leaves and moss near small vernal pools (RWC) 1 female; York Co., Canterbury, Trail to Browns Mtn. Fen., 45.9033°N, 67.6260°W, 2.V.2005 // Mixed forest with cedar, margin of vernal pond in moist leaf litter (LFC) 1 sex undetermined; York Co., New Maryland, off Hwy 2, E of Baker Brook, 45.8760°N, 66.6252°W, 26.IV.2005, R.P. Webster // Old growth cedar swamp, in moss and litter at base of cedar (RWC) 1 female; York Co., NE of Exit 271 off Hwy 2, 45.8776°N, 66.8254°W, 8.VI.2008, R.P. Webster // Alder swamp with poplar, sifting leaf litter & moss near vernal pool (RWC) 1 female; ONTARIO: Leeds and Grenville. Co., 2 km SE Spencerville, 30.IV.1979, A. & Z. Smetana (CNC) 1 male, 1 female.

Etymology.

The specific name bicornis means 'with two horns’ in allusion to the two teeth on the male tergite VIII.

Diagnosis.

Dinaraea bicornis (habitus Fig. 1a) may be distinguished from congeners by the following combination of characters: body length 3.1-3.4 mm; head and pronotum matte with dense microsculpture; pronotum broadest at apical third; elytra at suture shorter than pronotum, with asperate punctation; antennal articles 7-10 strongly transverse; male tergite VIII with two small sharp apical teeth (Fig. 1c); median lobe of aedeagus with straight and short tubus narrowly rounded apically (Fig. 1b); spermatheca with pear-shaped capsule and moderately deep apical invagination, stem narrow, long and looped posteriorly, slightly swollen at apex (Fig. 1e).

Description.

Body length 3.1-3.4 mm; body dark brown with at least posterior part of elytra paler, with legs, antennae and labial palpi yellowish-brown; head and pronotum with dense microsculpture and appearing matte; elytral and particularly pronotal microsculpture less dense and their integument appears glossy; head about as broad as pronotum, genae slightly longer than eyes in dorsal view; pronotum broadest in apical third, slightly transverse, longer than elytra at suture; elytra transverse, shorter than pronotum at suture, truncate posteriorly; abdomen arcuate laterally, broadest in apical third; male tergite VIII with two small sharp medial teeth at apical margin (Fig. 1c), sternite VIII slightly produced posteriorly, antecostal suture arcuate (Fig. 1d); median lobe of aedeagus with short and straight venter of tubus and narrowly rounded apex (Fig. 1b); female tergite VIII slightly sinuate apically on each side of disc (Fig. 1f), sternite VIII rounded apically, antecostal suture sinuate (Fig. 1g); spermatheca with pear-shaped capsule and moderately deep apical invagination, stem narrow, long and looped posteriorly, slightly swollen at apex (Fig. 1e).

Distribution.

Known from New Brunswick and Ontario.

Collection and habitat data.

Most adults were collected in April and May, and one specimen in October. The New Brunswick specimens were found in moss and leaf litter near the edges of small vernal pools in forests containing eastern white cedar ( Thuja occidentalis L.) and red maple ( Acer rubrum L.), and sometimes alder and poplar.