Gnypeta impressicollis Klimaszewski, Brunke & Pentinsaari, 2021

Brunke, Adam J., Pentinsaari, Mikko & Klimaszewski, Jan, 2021, Integrative taxonomy of Nearctic and Palaearctic Aleocharinae: new species, synonymies, and records (Coleoptera, Staphylinidae), ZooKeys 1041, pp. 27-99 : 27

Gnypeta impressicollis Klimaszewski, Brunke & Pentinsaari sp. nov. Fig. 13A-H

Type material.

Holotype. (male, CNC): Canada, Ontario, Hartington, Eel Lake, South Frontenac, Paul Hebert’s cottage property, 44.563°N, 76.549°W, 6.13.2017, Mikko Pentinsaari, Barcode of Life DNA voucher specimen, Sample ID: BIOUG34206-H01, Process ID: MPCAN465-17. Paratypes (3 CBG, 4 CNC): Canada, labelled as the holotype except: Sample ID: BIOUG34206-H02, Process ID: MPCAN466-17 (1 male, CBG); Sample ID: BIOUG34206-G12, Process ID: MPCAN464-17 (1 male, CBG); Sample ID: BIOUG34206-G11, Process ID: MPCAN463-17 (1 female, CBG). United States: North Carolina: Haywood Co., 3 mi N Dellwood, 19.VIII.1972, A. Smetana (3, CNC); Maryland: Patuxent Wildl. Res. Ctr., 5 km E Montpelier, treading pond vegetation, 16.VI.1982, Bousquet & Davies (1, CNC).

Etymology.

The species epithet refers to the longitudinal impression on the pronotum, most strongly developed in males.

Diagnosis.

Gnypeta impressicollis can be easily distinguished from all Nearctic species of the genus (except eastern G. baltifera (LeConte)) by the hexagonal pronotum with a longitudinal impression in the basal half (females) to nearly entire pronotal length (males). Males also have an impression on the vertex of the head. We have examined the female type of G. baltifera and it is externally similar but differs by the shorter, less angulate hexagonal pronotum, reddish and longer elytra and spermatheca with an elongate stem (C-shaped in G. impressicollis ).

Description.

Body length 3.2-3.4 mm; colour dark brown, elytra brown with irregular rust-brown patches, first two or three basal tergites rust-brown with posterior edge yellow, apex of abdomen rust-brown, legs and antennae rust-brown; integument highly glossy (Fig. 13A ); pubescence yellowish grey, moderately long and moderately sparse; all antennomeres distinctly elongate; head round with short neck (visible only when head is distended from thorax), vertex in males with broad central impression, vertex of females with much smaller and narrower median impression, maximum width of head slightly less than maximum width of pronotum; pronotum hexagonal in shape, ca. as long as head, with a longitudinal impression in the basal half (females) to nearly entire pronotal length (males), pubescence on disc directed anteriad along midline and obliquely laterad elsewhere; elytra wider than either head or pronotum, at suture shorter than pronotum along midline, pubescence directed obliquely posteriad forming wavy pattern medially on each side; abdomen arcuate laterally, broadest in apical third, at base distinctly narrower than elytra; legs very long, hind tarsus with basal tarsomere ca. as long as the two following ones combined. MALE. Tergite VIII with apical margin truncate medially and arcuate laterally (Fig. 13E ); sternite VIII elongate, narrowed apically, apex truncate medially and oblique laterally (Fig. 13F ); median lobe of aedeagus in lateral view with tubus very short, triangular and gradually tapering to narrowly rounded apex, ventral margin broadly curved ventrad in apical half (Fig. 13B ); in dorsal view bulbus moderately large and tubus swelled basally and triangular apically (Fig. 13C ); internal sac with complex membranous structures (Fig. 13B,C ). FEMALE. Tergite VIII broadly arcuate apically (Fig. 13G ); sternite VIII rounded apically with very shallow median emargination (Fig. 13H ); spermatheca C-shaped, capsule subspherical with broad apical invagination, stem tubular and C-shaped (Fig. 13D ).

Distribution.

Origin: Nearctic. Canada: ON. United States: MD, NC. Gnypeta impressicollis is probably broadly distributed in eastern North America.

Bionomics.

Specimens were collected by sifting leaf litter along a lake margin and by treading pond vegetation.

Comments.

It was challenging to place this species in either Gnypeta or Ischnopoda Stephens based on the concepts of Paśnik (2010). The extremely long legs, pronotal shape, C-shaped spermatheca and superficial punctation of the pronotum and abdomen are consistent with at least some Neotropical members of Ischnopoda but the ligula of G. impressicollis is divided to the base, which is considered to be a feature of Gnypeta ( Pašnik 2010). The C-shaped spermatheca of Gnypeta impressicollis also bears some similarity to the G. crebrepunctata group of Klimaszewski et al. (2008) but it is rather different in external morphology. We place this species in Gnypeta pending future systematic research.

Figures

Figure 13. Gnypeta impressicollis Klimaszewski, Brunke & Pentinsaari, sp. nov. A habitus B median lobe of aedeagus in lateral view C median lobe of aedeagus in dorsal view D spermatheca E male tergite VIII F male sternite VIII G female tergite VIII H female sternite VIII. Scale bars: 1 mm (A); 0.2 mm (B-H).