Gnypeta manitobae, 2018

Klimaszewski, Jan, Godin, Benoit, Davies, Anthony, Bourdon, Caroline & Horwood, Denise, 2018, Forty new records of aleocharine beetles, and two new species in the genera Acrotona Thomson and Atheta Thomson, for the province of Manitoba, Canada (Coleoptera: Staphylinidae: Aleocharinae), Insecta Mundi 2018 (641), pp. 1-33 : 11-12

Atheta (subgenus undetermined) manitobae Klimaszewski and Godin , new species

Fig. 1–16

Holotype. Canada: Manitoba, Moose Lake , 2016-IX-19, 49.2018°N, 95.3423°W, 353 m, Birch litter, sifting, B. Godin & D. Horwood ( CNC) 1 female.

Paratype. Canada: Manitoba, Moose Lake, 2016-IX-19, 49.2018°N, 95.3423°W, 353 m, Birch litter, sifting, B. Godin & D. Horwood ( LFC) 1 male.

Etymology. Named after the Canadian province of Manitoba, where the type specimens were found.

Description. Body narrow, subparallel, length 2.7–2.8 mm; head, antennae, pronotum, and abdomen (except for its apex), dark brown, elytra and legs light brown or light reddish-brown ( Fig. 9 ); antennomeres V-VI elongate, and VII-X subquadrate; pronotum transverse (maximum width 0.6 mm), evenly arcuate laterally, slightly narrower than maximum width of elytra, arcuate basally ( Fig. 9 ); elytra strongly transverse (maximum width 0.7 mm), distinctly shorter than pronotum ( Fig. 9 ); abdomen subparallel, with very coarse macrosetae apically; legs very long ( Fig. 9 ). Male. Tergite VIII transverse, arcuate apically ( Fig. 12 ); sternite VIII broadly parabolic, slightly truncate apically, with numerous strong macrosetae in apical part of disc except medially, antecostal suture almost straight and narrowly separated from basal margin medially ( Fig. 13 ); median lobe of aedeagus in dorsal view with bulbus narrowly oval, tubus long and broad, slightly tapering to triangular apex ( Fig. 11 ), in lateral view ventral margin of tubus strongly curved ventrad in basal half, almost straight to narrowly elongate subapical part, apex narrowly rounded ( Fig. 10 ). Female. Tergite VIII, transverse, truncate medially at apex ( Fig. 14 ); sternite VIII broadly parabolic from base to apex, with numerous strong macrosetae in apical part of disc, antecostal suture sinuate, moderately separated from basal margin ( Fig. 15 ); spermatheca with capsule small, pear-shaped with deep apical invagination, stem long, thin and arcuate medially, narrowly recurved posteriorly ( Fig. 16 ).

Distribution. Known only from the type locality in Manitoba.

Collection and habitat data. Habitat. associated with birch forest; adults found in litter. Collecting period. IX. Collecting method. sifting forest litter.

Comments. This species differs from other Atheta species in having a broad and shield-shaped pronotum, evenly arcuate laterally, slightly wider than the maximum width of the elytra; elytra shorter than the pronotum; macrosetae of the apical part of the abdomen strong; antennomeres VII–X subquadrate; legs very long (middle and hind legs each as long as length of pronotum and elytra combined); and the shape of the median lobe of the aedeagus and spermatheca are distinctive ( Fig. 10, 11 ). The shape of median lobe of the aedeagus is similar to some species of the subgenus Dimetrota of Atheta , but all species of this subgenus known to us have the apical margin of male tergite VIII modified, with lateral teeth and a median emargination, which is lacking in this species.

In Benick and Lohse (1974) this species would key to “Mischgruppe II” [= mixed group] of Atheta . A female was designated as a holotype for this species because of the unique shape of the spermatheca.

Figures

Figures 1–8. Acrotona manitobensis Klimaszewski and Godin, sp. nov., habitus and male structures of holotype. 1) Habitus in dorsal view. 2) Median lobe of aedeagus in lateral view. 3) Median lobe of aedeagus in dorsal view. 4) Male tergite VIII. 5) Male sternite VIII. 6) Female tergite VIII. 7) Female sternite VIII. 8) Spermatheca. Scale bar for habitus = 1 mm, remaining scale bars = 0.2 mm.

Figures 9–16. Atheta manitobae Klimaszewski and Godin, sp. nov., habitus and female structures of holotype. 9) Habitus in dorsal view. 10) Median lobe of aedeagus in lateral view. 11) Median lobe of aedeagus in dorsal view. 12) Male tergite VIII. 13) Male sternite VIII. 14) Female tergite VIII. 15) Female sternite VIII. 16) Spermatheca. Scale bar for habitus = 1 mm, remaining scale bars = 0.2 mm.