Eupines (Byraxis) gigas, 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 : 30-31

Eupines (Byraxis) gigas sp. nov.

Fig. 18 ; map Fig. 50

Diagnosis: Head with vertexal foveae punctiform, surrounded by shallow impressions; antennae 10-segmented with 2-segmented antennal club; A4, A5, A6, A7 and A8 unmodified, A9 enlarged, ventral side truncate, A10 largest and conical, about twice length of A9, with deep basal excavation at ventral side. Abdominal ventrite 2 with pair of small and flat discal protuberances, inserted with strongly curved long apical setae; ventrite 6 with pair of long median struts, curved towards each other, slightly longer than half of ventral length. Protrochanters with long and acute ventral spine, about as long as protrochanteral width; protibiae and mesotibiae unmodified.

Description: Body length 1.95–2.07 mm; body colour reddish brown to dark brown with lighter coloured elytra and legs. Head wider than long; frons not narrowed at end, about three-fourths width of head at eye level; eyes well developed, conspicuously prominent in dorsal view, with about 36 facets; vertexal foveae punctiform, surrounded by shallow impressions; antennal tubercles moderately developed; postantennal notches distinctive and broad; postantennal cavities large, about as long as antennal tubercles in dorsal view; antennae 10-segmented with 2-segmented antennal club; A4, A5, A6, A7 and A8 unmodified, A9 enlarged, ventral side truncate, A10 largest and conical, about twice length of A9, with deep basal excavation at ventral side. Pronotum about as long as wide, slightly narrower than head at eye level; lacking lateral antebasal foveae. Elytra as long as wide, widest near apical two-thirds; 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 small and flat discal protuberances, inserted with strongly curved long apical setae; ventrite 6 with pair of long median struts, curved towards each other, slightly longer than half of ventral length. Legs with protrochanters modified with long and acute ventral spine, about as long as protrochanteral width; protibiae and mesotibiae unmodified. Aedeagus about 0.34 mm long, with parameres elongate, widest near middle, slightly curved outwards at apex, bent downwards in lateral view, with four pairs of short subapical setae and pair of short apical setae; median lobe with single small and stout sclerite, narrower than parameres.

Comments: This species is similar to E. (B.) dispar by sharing a large body size (average length around 2.00 mm), but can be easily recognized by its conical A10, while it is bean-shaped in E. (B.) dispar ( Figs. 15 B–D).

Distribution: North Island. TO, BP, TK, HB.

Etymology: This specific epithet is a Latin adjective meaning ‘large’, referring to the large body size of this species.

Type material ( NZAC): Holotype. ♂, specimen entire, point-mounted: “ NEW ZEALAND, BP, Upper Waipi- ata Karakatuwhero V. 3 Feb 1993, J.S. Dugdale // Litter 93/15”. Paratypes . 8 ex.: TO: 1, Ohakune R.C. Craw // litter, 85/67; 1, Kaimanawa SF., 26/Mar/1978, S.B. Peck, litter; 2, Opepe 27/Mar/1978, S.B. Peck Litter; BP: 1, Orete Forest, Te Puia Hut, 25–29/Jan/1993, R.C. Henderson // Pan trap; 1, Coll. A.E. Brookes, 26/Dec/1943 // leaf mould // Kaimai Range, Matamata, Waikato // A.E Brookes Collection; TK: 1, Mt. Egmont 3500’, 17/Apr/1965, litter, N.A. Walker; HB: 1, Waipukurau Lindsay Reserve , 28/Dec/1981, J.C. Watt // sifted litter 81/218 .

Figures

FIGURE 15. Diagnostic characters of E. (B.) dispar (Sharp, 1874). A) Habitus. B) Antenna, in dorsal view. C) Same, in lateral view. D) Same, in ventral view. E) Protrochanter. 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 18. Diagnostic characters of E. (B.) gigas sp. n. A) Habitus. B) Antenna, in dorsal view. C) Same, in lateral view. D) Same, in ventral view. E) Protrochanter. 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 50. Geographic distributions of E. (B.) crassicornides Newton, 2017, E. (B.) decens (Broun, 1893), E. (B.) dispar (Sharp, 1874), E. (B.) dugdalei sp. n., E. (B.) fraudulenta (Broun, 1886) and E. (B.) gigas sp. n. in New Zealand.