Eupines (Byraxis) minuta, 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 : 52-53

Eupines (Byraxis) minuta sp. nov.

Fig. 33 ; map Fig. 53

Diagnosis: Head with vertexal foveae punctiform; antennae 10-segmented with 2-segmented antennal club; A4, A6, A7, A8 and A10 unmodified, A5 greatly enlarged and asymmetrical, lateral side with large and shallow basal impression, A9 cylindrical, about 5 × longer than A8, A10 conical, about 1.4 × longer than A9. Abdominal ventrite 2 with pair of large and round discal protuberances, inserted with strongly curved small anterolateral setae; ventrite 6 with pair of short and acute median struts, about one-fourth of ventral length. Protrochanters with minute ventral spine, about one-seventh of protrochanteral width; protibiae unmodified; mesotibiae with minute apical spine.

Description: Body length 1.41–1.48 mm; body colour dark brown with lighter coloured tarsi. Head as long as wide; frons greatly narrowed at end, about one-third width of head at eye level; eyes moderately developed, slightly prominent in dorsal view, with about 27 facets; vertexal foveae punctiform; antennal tubercles weak; postantennal notches distinctive and small; postantennal cavities small, about half length of 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, lateral side with large and shallow basal impression, A9 cylindrical, about 5 × longer than A8, A10 conical, about 1.4 × longer than A9. Pronotum about as long as wide, wider than head at eye level; with punctiform lateral antebasal foveae. Elytra as long as wide, widest at middle; humeral calli weak, slightly prominent in dorsal view; sutural stria shallowly extending from base to apex. Abdomen with tergite 1 about twice length of tergite 2; ventrite 2 with pair of large and round discal protuberances, inserted with strongly curved small anterolateral setae; ventrite 6 with pair of short and acute median struts, about one-fourth of ventral length. Legs with protrochanters modified with minute ventral spine, about one-seventh of protrochanteral width; protibiae unmodified; mesotibiae with minute apical spine. Aedeagus about 0.32 mm long, with long and stout parameres, curved downwards in lateral view, apex slightly curved, with pair of long subapical setae; median lobe with two long and stout sclerites, slightly twisted at apex, slightly shorter and narrower than parameres.

Comments: This species is characterized by a A5 greatly enlarged and asymmetrical ( Figs. 33 B–C).

Distribution: South Island. SD, NN.

Etymology: The specific epithet refers to the minute apical spine on mesotibiae of this species.

Type material ( NZAC): Holotype. ♂, specimen in two parts, head + thorax glued on card, abdomen mounted on acetate card: “ NEW ZEALAND, NN, Stockton Coal Mine W6C dump 880m, 13–20 Dec 2000 [handwritten], R.J. Toft // Rehabilitation trial Bare control plot Malaise trap, 9 [handwritten], RT”. Paratype . 3 ex.: SD: 2, FMNH , Tennyson Inlet, west side Te Mako Bay, 125 m, 15/xii/1984 – 5/i/1985, Nothofagus-podo-hdwd., A. Newton / M. Thayer, 710; NN: 1, Mt. Arthur , 1200 m, Nelson, 13–20/Nov/1969, B. May & S. Silcock .

Figures

FIGURE 33. Diagnostic characters of E. (B.) minuta sp. n. A) Habitus. B) Antenna, in dorsal view. C) Same, in lateral view. D) Protrochanter. E) Mesotibia. 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.