Eupines (Byraxis) obtusa, Shen & Leschen, 2020

Shen, Jia-Wei & Leschen, Richard A. B., 2020, Revision of Eupines King of New Zealand (Coleoptera: Staphylinidae: Pselaphinae: Goniaceritae), Zootaxa 4777 (1), pp. 1-84 : 59-60

Eupines (Byraxis) obtusa sp. nov.

Fig. 38 ; map Fig. 53

Diagnosis: Head lacking vertexal foveae; antennae 10-segmented with 2-segmented antennal club; A4, A6, A7, A8 and A10 unmodified, A5 greatly enlarged and asymmetrical, about 3.5 × longer than A4, A7 slightly asymmetrical, A8 about half length of A7, A9 large, about as long as A10, base slightly impressed at dorsal side, widest near apex, A10 conical. Abdominal ventrite 2 with pair of large discal protuberances, inserted with strongly curved small apical setae; ventrite 6 with pair of long median struts, about one-third of ventral length. Protrochanters with long and acute ventral spine, about three-fifths of protrochanteral width; protibiae with large and blunt apical protuberance; mesotibiae unmodified.

Description: Body length 1.42–1.50 mm; body colour dark brown to black with lighter coloured legs. Head wider than long; frons slightly narrowed at end, about half width of head at eye level; eyes moderately developed, with about 23 facets; lacking vertexal foveae; antennal tubercles barely visible; lacking postantennal notches; postantennal cavities long and wide, slightly longer than antennal tubercles in dorsal view; antennae 10-segmented with 2-segmented antennal club; A4, A6, A7,A8 and A10 unmodified, A5 greatly enlarged and asymmetrical, about 3.5 × longer than A4, A7 slightly asymmetrical, A8 about half length of A7, A9 large, about as long as A10, base slightly impressed at dorsal side, widest near apex, A10 conical. Pronotum as long as wide, slightly wider than head at eye level; lacking lateral antebasal foveae. Elytra slightly longer than wide, widest near middle; humeral calli slightly prominent; sutural stria shallowly extending from base to apex. Abdomen with tergite 1 about 1.2 × longer than tergite 2; ventrite 2 with pair of large discal protuberances, inserted with strongly curved small apical setae; ventrite 6 with pair of long median struts, about one-third of ventral length. Legs with protrochanters modified with long and acute ventral spine, about three-fifths of protrochanteral width; protibiae with large and blunt apical protuberance; mesotibiae unmodified. Aedeagus about 0.33 mm long, with long and stout parameres nearly meet at apex, bent downwards in lateral view, with two pairs of long subapical setae and pair of short apical setae; median lobe with two slender sclerites, slightly sinuate, strongly curved towards each other at apex, much narrower than parameres.

Comments: This species can be distinguished from all other species by its protibiae modified with rounded apical protuberance, along with it modified A5 ( Figs. 38 B–E).

Distribution: North Island. TO, TK. South Island. WD.

Etymology: This specific epithet is a Latin adjective meaning ‘blunt’, referring to the blunt apical protuberance on protibiae of this species.

Type material ( NZAC): Holotype. ♂, specimen entire, point-mounted: “ NEW ZEALAND, WD, Mt. Tuhua , 1067 m, E. side of L. Kaniere, 20 Nov 1984 // B.A. Holloway Moss and lichen 84/75”. Paratypes . 7 ex.: TO: 1, Whanganui V., 792 m, Whenuakura Flats , 11/Oct/1979, J.S. Dugdale // bryophytes, 79/94; TK: 3, Pouakai Hump, 1220 m, 03/Dec/1975, A.K. Walker // litter moss, 75/211; 1, W. edge Hump Plat. Pouakai Ra., 01/Dec/1975, J.S. Dugdale // litter, 75/200; 1, Holly Hut, 950 m, North Egmont, Nov /1975, A.K. Walker // beating; WD: 1, same data as holotype .

Figures

FIGURE 38. Diagnostic characters of E. (B.) obtusa sp. n. A) Habitus. B) Antenna, in dorsal view. C) Same, in lateral view. D) Protrochanter. E) Protibia. F) Ventrite 2. G) Ventrite 6. H) Aedeagus, in dorsal view. I) Same, in lateral view. J) Same, in ventral view. Scale bars: A = 1 mm, B–F = 0.2 mm, G–J = 0.1 mm.

FIGURE 53. Geographic distributions of E. (B.) minuta sp. n., E. (B.) monstrosa (Reitter, 1880), E. (B.) mundula (Schaufuss, 1888), E. (B.) nemoralis (Broun, 1886), E. (B.) novem sp. n., E. (B.) obtusa sp. n., E. (B.) ovalis sp. n. and E. (B.) paganus (Broun, 1881) in New Zealand.