Nesamblyops oreobius (Broun), 1973

Sokolov, Igor M., 2023, Eight new species of the genus Nesamblyops Jeannel (Anillini: Carabidae: Coleoptera) from New Zealand with notes about dispersal of the genus to the North Island, Zootaxa 5230 (2), pp. 179-201 : 188-191

Nesamblyops oreobius (Broun) (dissected 16 specimens)

Figs. 2F , 4F , 5P–R , 7D , 8A , 11

= Tachys oreobius Broun, 1893: 1399 .

= Tachys coriaceus Broun, 1908: 421 . Synonymy established by Moore (1980: 400).

= Anillus monticola Broun, 1910: 10 . Synonymy established by Jeannel (1937: 281).

Examined material (more than 280 specimens): WO: Mt.Karioi ,nr base, nr summt, 11 Oct 1981, C.F.Butcher, litter 81/95 (5ex.) ; Tangarakau Gorge , 450m, 18-4-65, N.A.Walker, litter (1ex.) ; Mt.Pirongia , 962m, 16 Jan 1977, A.K.Walker, litter 77/2 (2ex.) , Mt.Pirongia , 2500’, 23-9-64, litter, G.Kushel (1ex.) ; TeKauri Scenic Reserve, nr Kawhia , 20 Sep 1981, C.F.Butcher, litter 81/89 (6ex.) ; Waitomo, Maori L., Tumutumu Rd. , 24 May 1983, J.C.Watt, litter and soil 83/60 (5ex.) ; Waipuna Reserve near Waitomo , 28 Oct 1977, A. R. Ferguson, litter 77/134 (4ex.) ; Herangi Range, 500m, above Mangatoa Saddle , 9 Dec 1982, J.S.Dugsdale, mixed swards and bryophytes 82/134 (8ex.) ; Mohoenui, Gribbons Road , 26 Jun 1977, N.H.Mancer or G.W.Ramsay, litter 77/78 (118ex.) ; Mt.Messenger , 610’, Taranaki, 24.xi.68, J.S.Dugsdale, litter 68/196 (1ex.) ; TK: Pouakai Range, 1006m, Ahuwakawa Track , 11 Jan 1978, J.C.Watt, litter 78/11 (30ex.) , same but, 1067m, litter and moss 78/10 (5ex.), same but, 1220m, 9 Jan 1978, litter78/13 (4ex.); Mt.Egmont , 3500’, 2-4.1.82, G.Kushel, leafmould (9ex.) ; Mt.Egmont , 823m, Taranaki, 29 Nov 70, A.W.Don, litter (3ex.) ; Mt.Egmont , 4600’, Stratford side, 25.x.68, J.S.Dugsdale, mat plants 68/198 (2ex.) ; Mt.Egmont, 1000m, Stratford Rd. , 22 Feb 1984, B.M.May, litter 84/52 (1ex.) ; Egmont NP, Ngatoro TK, 650m, 19.III.1998, Larochelle, Larivière, wet broadleaf forest along mud flats, in litter & rotten wood on & along big logs (1ex.) ; N Egmont , 23 Feb 1984, B.M.May, litter 84/51 (1ex.) ; 853m E Egmont, Nov 76, K.E.Fox, moss beside Kamahi Track (5ex.) ; Summit track, 4500’, Mt.Egmont , 15.6.65, J.I.Townsend, moss sample from wet bank above Hooker Hut (1ex.) ; Stratford Plat. , 4000’, 15-6-65, moss, J.I.Townsend (5ex.) ; Stratford Plt. Rd., Mt.Egmont , 1800’, 17-4-65, litter, N.A.Walker (2ex.) , same but 2150’ (3ex.), same but 2550’ (1ex.), same but 2600’ (1ex.), same but 3250’ (1ex.), same but 3500’ (2ex.); Mt Egmont NP, Stratford Mtn. House , 846m, 23 May 1986, C.L.Lyal, Leaf litter, CL 474 (2ex.) ; Wilkies Pools, track litter, Dawson Falls , 3200’, 16-6-65, J.I.Townsend (2ex.) ; Dawson Falls, 975m, Mt.Egmont , Taranaki, 16 Jun 65, J.I. Townsend, litter 65/387 (1ex.) ; Pouakai Hump , 1220m, 3 Dec 1975, A.K.Walker, dry moss 75/213 (4ex.) ; W edge Hump , Plat. Pouakai Ra., 2 Dec 1975, J.S. Dugsdale, litter 75/200 (1ex.) ; Pouakai Ra, 1372m, Summit Ridge , 10 Jan 1978, J.C.Watt, litter 78/9 (2ex.) , same but 1400m, litter 78/8 (1ex.); Pouakai Trig, Pouaki Range , 3 Dec 1975, litter 75/206 (4ex.) , same but moss 75/208 (12ex.), same but litter 75/209 (3ex.); Pouakai Saddle , 1220m, Pouakai Ra., 3 Dec 1975, J.S. Dugsdale, litter 75/202 (2ex.) , same but Poa colensoi swards 75/203 (10ex.), same but litter 75/204 (9ex.), same but litter 75/205 (6ex.); Pouakai Ra. Hut , 1280m, 2 Dec 1975, A.K. Walker, litter 75/210 (1ex.) ; Tangarakau Gorge , 31-12-78 (1 ex.) .

The description of N. oreobius contains little diagnostic information that allows correct identification. Below, I redescribe the species to make comparison of N. oreobius with other species easier.

Type locality. New Zealand, North Island, Waikato, Mount Pirongia .

Recognition. Adults of this species ( Fig. 2F ) are practically indistinguishable from the adults of many Nesamblyops species based on external characters (cf. with Figs. 2A–C ) and are distinguished from them by the structure of the male genitalia.

Description. Medium sized for genus (SBL range 1.51–1.83 mm, mean 1.68±0.100 mm, n=23).

Habitus. Body form ( Fig.2F ) markedly convex, elongate ovoid, general proportions wide (WE/SBL 0.40±0.008), head narrow relative to pronotum (WH/WPm 0.70±0.014), proportions of pronotum in comparison to elytra average for genus (WPm/WE 0.76±0.027).

Color. Body color brunneorufous, appendages testaceous.

Prothorax. Pronotum ( Fig. 4F ) moderately long in comparison to elytra (LP/LE 0.41±0.016) and moderately transverse (WPm/LP 1.26±0.021), with lateral margins arcuately and strongly constricted posteriorly (WPm/WPp 1.34±0.032). Anterior angles indistinct, posterior angles obtuse (111–124°), rounded. Width between posterior angles greater than between anterior angles (WPa/WPp 0.93±0.029). Basal margin almost rectilinear, slightly convex at middle.

Elytra. Ovoid, narrowly depressed along suture, comparatively long (LE/SBL 0.58±0.008) and wide (WE/LE 0.72±0.026). Humeri completely rounded. Lateral margins slightly divergent at basal half, shortly subparallel at middle and evenly rounded to apex in apical half.

Male genitalia. Median lobe of aedeagus ( Fig. 5R ) strongly arcuate and moderately twisted. Shaft subparallel in basal half, tapering in apical half. Apex slightly curved dorsally with narrowly rounded tip. Apical orifice occupies about one third of the shaft length. Ventral margin of median lobe straight. Walls of shaft with poriferous canals at basal half. Dorsal copulatory sclerites with V-shaped plate, directed with its sharp end apically. Scaled membraneous fields lacking. Spines of internal sac absent. Left paramere ( Fig. 5P ) comparatively wide, with shortly attenuate apex, bearing three long setae. Right paramere ( Fig. 5Q ) moderately long and wide, bearing three long setae, which are shorter the length of paramere. Ring sclerite as in Fig. 7D .

Female internal genitalia. Spermatheca ( Fig. 8A ) sclerotized, of bulb-like shape with wide circular apical part and narrow basal part. Length of spermatheca shorter than the lengths of either spermathecal gland or spermathecal duct. Spermathecal duct short without coils. Attachments of spermathecal duct and gland to spermatheca close together.

Geographical distribution. This species is distributed only on the North Island, where it is known from the Taranaki and Waikato areas ( Crosby et al. 1998) from Mount Taranaki (former Mount Egmont) in the south, north to Mount Pirongia ( Fig. 11 ).

Habitat. According to label data, specimens were collected from leafmold, litter, and moss without more precise data about plant communities.

Relationships. The structure of the male genitalia of N. oreobius , especially the V-shaped sclerite of the internal sac suggests a possible relationship to the other species with similar configuration of copulatory sclerites, such as N. confusus and N. lescheni .

Figures

FIGURE 2. Digital images of habitus of New Zealand Nesamblyops species, dorsal aspect. A—N. brouni (Lewis Pass, North Canterbury, SO), B—N. carltoni (Dun Mountain, Nelson, SO), C—N. confusus (Mount Stokes, Marlborough Sounds, SO), D—N. distinctus (Fabians Valley, Marlborough, SO), E—N. lescheni (D’Urville Island, Cook Strait, Marlborough Sounds, SO), F—N. oreobius (Mount Pirongia, Waikato, NO). Scale bar 1.0mm.

FIGURE 4. Digital images of pronota of New Zealand Nesamblyops species, dorsal aspect. A—N. brouni (Lewis Pass, North Canterbury, SO), B—N. carltoni (Dun Mountain, Nelson, SO), C—N. confusus (Mount Stokes, Marlborough Sounds, SO), D—N. distinctus (Fabians Valley, Marlborough, SO), E—N. lescheni (D’Urville Island, Cook Strait, Marlborough Sounds, SO), F—N. oreobius (Mount Pirongia, Waikato, NO), G—N. parvulus (Mount Stokes, Marlborough Sounds, SO), H—N. tararua (Judd Ridge, Tararua Range, Wellington, NO), I—N. townsendi (Tennyson Inlet, Marlborough Sounds, SO). Scale bar 0.2mm.

FIGURE 5. Line drawings of male genitalia of New Zealand Nesamblyops species. N. brouni (Lewis Pass, North Canterbury, SO): A—left paramere, left lateral aspect, B—right paramere, right lateral aspect, C—median lobe, right lateral aspect. N. carltoni (Dun Mountain, Nelson, SO): D—left paramere, left lateral aspect, E—right paramere, right lateral aspect, F—median lobe, right lateral aspect. N. confusus (Mount Stokes, Marlborough Sounds, SO): G—left paramere, left lateral aspect, H—right paramere, right lateral aspect, I—median lobe, right lateral aspect. N. distinctus (Fabians Valley, Marlborough, SO): J—left paramere, left lateral aspect, K—right paramere, right lateral aspect, L—median lobe, right lateral aspect. N. lescheni (D’Urville Island, Cook Strait, Marlborough Sounds, SO): M—left paramere, left lateral aspect, N—right paramere, right lateral aspect, O—median lobe, right lateral aspect. N. oreobius (Mount Pirongia, Waikato, NO): P—left paramere, left lateral aspect, Q—right paramere, right lateral aspect, R—median lobe, right lateral aspect. Scale bar 0.1mm.

FIGURE 7. Line drawings of ring sclerite of New Zealand Nesamblyops species, male genitalia, dorsal aspect. A—N. brouni (Lewis Pass, North Canterbury, SO), B—N. carltoni (Dun Mountain, Nelson, SO), C—N. distinctus (Fabians Valley, Marlborough, SO), D—N. oreobius (Mount Pirongia, Waikato, NO), E—N. lescheni (D’Urville Island, Cook Strait, Marlborough Sounds, SO), F—N. parvulus (Mount Stokes, Marlborough Sounds, SO), G—N. tararua (Judd Ridge, Tararua Range, Wellington, NO), H—N. townsendi (Tennyson Inlet, Marlborough Sounds, SO). Scale = 0.4mm.

FIGURE 8. Line drawings of spermatheca of New Zealand Nesamblyops species. A—N. oreobius (Mount Pirongia, Waikato, NO), B—N. lescheni (D’Urville Island, Cook Strait, Marlborough Sounds, SO). Scale = 0.05mm.

FIGURE 11. Distributional records for Nesamblyops oreobius (Broun) and images of male median lobe, obtained from specimens, collected in the line-connected with images localities. Red star—the type locality of Tachys oreobius Broun and Anillus monticola Broun. Scale bar= 0.5mm.