Nesamblyops confusus, Sokolov, 2023

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 : 184-185

Nesamblyops confusus , sp. nov.

Figs. 2C , 4C , 5G–I , 10

Type material. HOLOTYPE, male, in NZAC, dissected, labeled: \ Mt Stokes 1160m Marlborough 12 Oct 67 \ J.I.Townsend \ Litter 67/244 \ DSIR \ No \ NZ PB \. PARATYPES (2 specimens, in NZAC, dissected 1 male) , 1 female labeled same as holotype; 1 male labeled: \ Mt Stokes Marlb. 11.x.67 J.I.Townsend \ moss 67/247 \ DSIR \ Ns \ NZ PB \.

Etymology. The specific epithet is a Latin adjective, confusus , in the masculine form, meaning “having been mixed”, and refers to the similarity between the external appearance of the new species and its closest relatives.

Type locality. New Zealand, South Island, Marlborough Sounds, Mount Stokes .

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

Description. Average size for genus (SBL range 1.64–1.67 mm, mean 1.66± 0.017 mm, n=3).

Habitus. Body form ( Fig.2C ) markedly convex, elongate ovoid, general proportions wide (WE/SBL 0.42±0.012), head narrow relative to pronotum (WH/WPm 0.68±0.038), in comparison with other species pronotum less bulky in comparison to elytra (WPm/WE 0.72±0.027).

Color. Body color dark brunneous, appendages testaceous.

Prothorax. Pronotum ( Fig. 4C ) moderately long in comparison to elytra (LP/LE 0.42±0.024) and moderately transverse (WPm/LP 1.24±0.013), with lateral margins arcuately and strongly constricted posteriorly (WPm/WPp 1.35±0.026). Anterior angles indistinct, posterior angles strongly obtuse (123–127°), widely rounded. Width between posterior angles slightly greater than between anterior angles (WPa/WPp 0.93±0.054). Basal margin slightly convex.

Elytra. Ovoid, narrowly depressed along suture, comparatively long (LE/SBL 0.59±0.015) and moderately wide (WE/LE 0.71±0.034). Humeri completely rounded. Lateral margins slightly divergent at basal third, subparallel at middle and evenly rounded to apex in apical third.

Male genitalia. Median lobe of aedeagus ( Fig. 5I ) moderately slightly arcuate and moderately twisted. Shaft arcuate, tapering in apical half. Apex slightly enlarged and straight with rounded tip. Apical orifice long, occupies almost half of the shaft length. Ventral margin of median lobe slightly concave in apical part. Walls of shaft with few poriferous canals apically. Dorsal copulatory sclerites with distinct V-shaped structure, directed with its sharp end apically. Scaled membraneous fields lacking. Spines of internal sac absent. Left paramere ( Fig. 5G ) comparatively wide, with shortly attenuate apex, bearing three long setae. Right paramere ( Fig. 5H ) short and wide, bearing three long setae, which are slightly longer the length of paramere.

Female internal genitalia. Not examined.

Geographical distribution. This species is known only from Mount Stokes in the Marlborough Sounds area ( Crosby et al. 1998) ( Fig. 10 , green circle).

Habitat. According to label data s pecimens were collected from moss without more precise data about plant communities.

Relationships. The structure of the male genitalia suggests the relationship of N. confusus to other species having a similar V-shaped structure of dorsal copulatory sclerites in the internal sac of the median lobe, such as N. oreobius (Broun) 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 10. Distributional records for the Nesamblyops species and images of male median lobe, obtained from specimens, collected in the line-connected with images localities. Black circles—N. carltoni; yellow circles—N. parvulus; red circles—N. lescheni; green circles—N. confusus. Scale bar= 0.5mm.