Nesamblyops rotundicollis, Sokolov, 2023

Sokolov, Igor M., 2023, Fourteen new species of the genus Nesamblyops Jeannel (Coleoptera: Carabidae: Anillini) from the South Island of New Zealand with redescription of the genus and description of a new subtribe, Zootaxa 5375 (2), pp. 151-192 : 178

Nesamblyops rotundicollis , sp. nov.

Figures. 10D , 13A , 15J–L , 17I , 18B , 20

Type material. HOLOTYPE, male, in NZAC, labeled: \ Ridge above Onekaka. Iron ore pit \ 20.v. 67 F. Alack \ litter 67/205 \ DSIR \ No \. PARATYPES (5 specimens, dissected 3), 1 male labeled: \ litter Nelson, N. Z. Parapara Inlet G.B. 15.II.72 J.I. Townsend \ J.I. Townsend Collection \; 1 female labeled: \ PuPu Valley 21.v . 67 F. Alack \ litter 67/204 \ DSIR \ No \ NZ PB \; 1 female labeled: \ PuPu Valley Takaka, Nelson 11 Nov. 71 J.I. Townsend \ NZ PB \; 1 female labeled: \ Paramahoi Nel. Litter 26-10- 65 L. P. Marchaut \ NZ PB \; 1 female labeled: \ Paramahoi Takaka Dist. Nel. 25.10.65 \ J.I. Townsend \.

Etymology. The specific epithet is a Latin adjective (from Latin rotundus meaning “round, circular” and collum meaning “neck”) in the masculine form and refers to the shape of pronotum of the new species.

Type locality. New Zealand, South Island, Nelson, Kahurangi National Park, Onekaka area .

Recognition. Adults of this species ( Fig. 10D ) are practically indistinguishable from the adults of many Nesamblyops species based on external characters (e.g., Figs 10E–F , 11A–B ) and are distinguished from them by the structures of the male genitalia.

Description. Large for genus (SBL range 1.84–2.07 mm, mean 1.92± 0.103 mm, n=4).

Habitus. Body form ( Fig. 10D ) moderately convex, elongate ovoid, general proportions slightly wide (WE/SBL 0.39±0.009), head narrow relative to pronotum (WH/WPm 0.70±0.014), proportions of pronotum in comparison to elytra average for genus (WPm/WE 0.72±0.006).

Color. Body color brunneorufous, appendages testaceous.

Prothorax. Pronotum ( Fig. 13A ) moderately long in comparison to elytra (LP/LE 0.41±0.006) and slightly transverse (WPm/LP 1.16±0.019), with lateral margins slightly and rectilinear constricted posteriorly (WPm/ WPp 1.22±0.023). Anterior angles indistinct, posterior angles obtuse (115–124°), widely rounded. Width between posterior angles greater than between anterior angles (WPa/WPp 0.85±0.041). Basal margin slightly convex.

Elytra. Ovoid, moderately depressed along suture, comparatively long (LE/SBL 0.59±0.002) and moderately wide (WE/LE 0.66±0.015). 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. 15L ) moderately arcuate and slightly twisted. Shaft almost subparallel in basal half, moderately tapering in apical half. Apex straight, subparallel and long with asymmetrically rounded wide tip. Apical orifice long, occupies almost half of the shaft length. Ventral margin of median lobe almost straight. Walls of shaft with group of poriferous canals at basal orifice. Dorsal copulatory sclerites atypical for genus. V-contour and rC-sclerite lacking. Instead of them only one dorsal membraneous field exists at the middle of shaft ( Fig. 15L ). The field has narrow sclerotization along its dorsal edge presumably corresponding to the dorsal branch of V-contour. Additionally, internal sac has scaly membraneous field of moderate size at apical orifice. Left paramere ( Fig. 15J ) comparatively narrow, with attenuate apex, bearing two long setae. Right paramere ( Fig. 15K ) narrow, of moderate length, bearing two long setae, which are shorter than the length of paramere. Ring sclerite as in Fig. 17I .

Female internal genitalia. Spermatheca ( Fig. 18B ) with two sclerotized compartments, a larger ball-shaped distal part and a short, curved, tube-like part representing sclerotized continuation of spermathecal duct. Tube-like part bears spermathecal gland, which is longer than the length of spermatheca. Spermathecal duct short, approximately equals the length of spermathecal gland.

Geographical distribution. The range of the species lies in the northwest corner of the South Island at the northeastern part of the Kahurangi National Park, where the species was collected on the eastern slopes of Parapara Peak ( Fig. 20 , pink circles).

Habitat. Specimens were collected mostly from litter samples.

Relationships. The structures of the male genitalia and parameres of N. rotundicollis suggests its relatedness to N. solitarius and N. subrufus , described below. All three species share bisetose parameres, the lack of rC-sclerite, and a scaly membraneous field near apical orifice in the internal sac of median lobe, the latter is presumably a synapomorphic character of this small group of species.

Figures

FIGURE 10. Digital images of habitus of New Zealand Nesamblyops species, dorsal aspect. A—N. montanus (Lake Sylvester, Kahurangi National Park, Nelson, SO), B—N. moorei (Kangaroo Creek, Mawhera Forest, Buller, SO), C—N. ovipennis (Mount Arthur, Nelson, SO), D—N. rotundicollis (Onekaka, Nelson, SO), E—N. solitarius (Italian Creek, Capleston, Buller, SO), F—N. subcaecus (Sharp) (Greymouth, Buller, SO). Scale bar = 1.0 mm.

FIGURE 11. Digital images of habitus of New Zealand Nesamblyops species, dorsal aspect. A—N. subrufus (Dublin Terrace, Upper Buller Gorge, Nelson, SO), B—N. viator (Secretary Island, Grono Bay, Fiordland, SO), C—N. victoriae (Capleston, Victoria Range, Buller, SO). Scale bar = 1.0 mm.

FIGURE 13. Digital images of pronota of New Zealand Nesamblyops species, dorsal aspect. A—N. rotundicollis (Onekaka, Nelson, SO), B—N. solitarius (Italian Creek, Capleston, Buller, SO), C—N. subcaecus (Greymouth, Buller, SO), D—N. subrufus (Dublin Terrace, Upper Buller Gorge, Nelson, SO), E—N. viator (Secretary Island, Grono Bay, Fiordland, SO), F—N. victoriae (Capleston, Victoria Range, Buller, SO). Scale bar = 0.2 mm.

FIGURE 15. Line drawings of male genitalia of New Zealand Nesamblyops species. N. montanus (Relax Shelter, Mount Robert Ridge, Nelson, SO): A—left paramere, left lateral aspect, B—right paramere, right lateral aspect, C—median lobe, right lateral aspect. N. moorei (Kangaroo Creek, Mawhera Forest, Buller, SO): D—left paramere, left lateral aspect, E—right paramere, right lateral aspect, F—median lobe, right lateral aspect. N. ovipennis (Mount Arthur, Nelson, SO): G—left paramere, left lateral aspect, H—right paramere, right lateral aspect, I—median lobe, right lateral aspect. N. rotundicollis (Onekaka, Nelson, SO): J—left paramere, left lateral aspect, K—right paramere, right lateral aspect, L—median lobe, right lateral aspect. N. solitarius (Italian Creek, Capleston, Buller, SO): M—left paramere, left lateral aspect, N—right paramere, right lateral aspect, O—median lobe, right lateral aspect. N. subacecus (Margarets Tarn Lake, Arthur’s Pass, Mid Canterbury, SO): P—left paramere, left lateral aspect, Q—right paramere, right lateral aspect, R—median lobe, right lateral aspect. Scale bar = 0.1 mm.

FIGURE 17. Line drawings of ring sclerite of New Zealand Nesamblyops species, male genitalia, dorsal aspect. A—N. canaanensis (Canaan, Nelson, SO), B—N. disjunctus (Fletchers Creek, Buller, SO), C—N. hobbit (Mount Domett, Nelson, SO), D—N. karamea (Karamea River Gorge, Nelson, SO), E—N. kuscheli (Flora Hut, Mount Arthur, Nelson, SO), F—N. montanus (Relax Shelter, Mount Robert Ridge, Nelson, SO), G—N. moorei (Kangaroo Creek, Mawhera Forest, Buller, SO), H—N. ovipennis (Mount Arthur, Nelson, SO), I—N. rotundicollis (Onekaka, Nelson, SO), J—N. subcaecus (Margarets Tarn Lake, Arthur’s Pass, Mid Canterbury, SO), K—N. viator (Secretary Island, Grono Bay, Fjordland, SO), L—N. victoriae (Capleston, Victoria Range, Buller, SO). Scale = 0.2 mm.

FIGURE 18. Line drawings of spermatheca of New Zealand Nesamblyops species. A—N. magnificus (Allison Reserve, Akatore, Dunedin, SO), B—N. rotundicollis (Parahamoi, Nelson, SO), C—N. subcaecus (Lake Kaniere Scenic Reserve, Mount Tuhua, Westland, SO). Scale = 0.1 mm.

FIGURE 20. Distributional records for the Nesamblyops species and images of male median lobe, obtained from specimens, collected in the line-connected with images localities. Green circles—N. solitarius; black circles—N. montanus; pink circles— N. rotundicollis; red circles—N. subrufus. Scale bar = 0.5 mm.