Nesamblyops hobbit, 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 : 168-169

Nesamblyops hobbit , sp. nov.

Figures. 9C , 12C , 14G–I , 17C , 19

Type material. HOLOTYPE, male, in NZAC, labeled: \ Mt.Domett 1000m 1 Dec 71 G.W.Ramsay \ Litter 71/176 \ DSIR \ No \ NZ PB \. PARATYPES (30 specimens, dissected 5 exx.), 6 males and 6 females labeled same as holotype; 1 male and 3 females labeled: \ Mt.Domett 1463m 1 Dec 71 J.S. Dugdale \ mat plants 71/181 \ DSIR \ No \ NZ PB \; 2 males and 2 females labeled: \ Mt.Domett 1250m Nov-Dec 71 G.Kuschel \ moss 71/169 \ DSIR \ No \ NZ PB \; 2 females labeled: \ MtDomett NN 1000m 1 Dec 71 G.W. Ramasay \ Litter 71/176 \ NZ PB \; 1 male labeled: \ L.Aorere 914m NN Mt.Domett Nov 71 \ J. McBurney \ moss 71/165 \ DSIR \ No \ NZ PB \; 6 males and 1 female labeled: \ 9 miles N. Karamea \ 1200’ 20.vi. 67 F. Alack \ litter 67/217 \ DSIR \ No \ NZ PB \.

Etymology. The specific epithet is a noun in apposition in the nominative case based on the imaginary race of people in the novel of J. R. R. Tolkien “The Hobbit”, and refers to this species’s way of life.

Type locality. New Zealand, South Island, Nelson, Kahurangi National Park, Mt Domett .

Recognition. Adults of this species ( Fig. 9C ) are practically indistinguishable from the adults of many Nesamblyops species based on external characters (e.g., Figs 9A , 10C ) and are distinguished from them by the structures of the male genitalia.

Description. Large for genus (SBL range 1.97–2.19 mm, mean 2.09± 0.082 mm, n=16).

Habitus. Body form ( Fig.9C ) markedly convex, elongate ovoid, general proportions wide (WE/SBL0.40±0.009), head narrow relative to pronotum (WH/WPm 0.66±0.028), proportions of pronotum in comparison to elytra average for genus (WPm/WE 0.75±0.018).

Color. Body color brunneorufous, appendages testaceous.

Prothorax. Pronotum ( Fig. 12C ) moderately long in comparison to elytra (LP/LE 0.42±0.010) and moderately transverse (WPm/LP 1.22±0.035), with lateral margins arcuately constricted posteriorly (WPm/WPp 1.30±0.026). Anterior angles indistinct, posterior angles obtuse (109–117°), rounded. Width between posterior angles greater than between anterior angles (WPa/WPp 0.86±0.029). Basal margin almost rectilinear, slightly convex at middle.

Elytra. Ovoid, narrowly depressed along suture, comparatively long (LE/SBL 0.59±0.005) and moderately wide (WE/LE 0.68±0.015). Humeri completely rounded. Lateral margins slightly divergent at basal half, subparallel at middle and evenly rounded to apex in apical third.

Male genitalia. Median lobe of aedeagus ( Fig. 14I ) moderately arcuate and moderately twisted. Shaft subparallel basally, tapering in apical half.Apex almost straight with narrowly rounded tip. Apical orifice long, occupies almost half of the shaft length. Ventral margin of median lobe straight. Walls of shaft with a number of poriferous canals scattered along ventral margin. Dorsal copulatory sclerites with well-developed rC-sclerite and reduced V-contour with short dorsal branch slightly protruding toward basal orifice ( Fig. 14I ). Left paramere ( Fig. 14G ) comparatively wide, with attenuate apex, bearing three long setae. Right paramere ( Fig. 14H ) long and narrow, bearing three long setae, which are slightly shorter than the length of paramere. Ring sclerite as in Fig. 17C .

Female internal genitalia. Not examined.

Geographical distribution. The species inhabits the central-western part of the Kahurangi National Park with a range stretching from the catchment of the Aorere River at the northeast to the northernmost parts of the West Coast District, South Island ( Fig. 19 , black circles).

Habitat. Specimens were collected from moss, mat plants, and litter samples.

Relationships. The structure of the male genitalia of N. hobbit suggests its relatedness to the other species with trisetose parameres, a well-developed rC-sclerite with small V-contour in the internal sac of median lobe, such as N. canaanensis and N. ovipennis , described below.

Figures

FIGURE 9. Digital images of habitus of New Zealand Nesamblyops species, dorsal aspect.A—N. canaanensis (Canaan, Nelson, SO), B—N. disjunctus (Fletchers Creek, Buller, SO), C—N. hobbit (9mi. N Karamea, Nelson, SO), D—N. karamea (Karamea River Gorge, Nelson, SO), E—N. kuscheli (Flora Hut, MountArthur, Nelson, SO), F—N. magnificus (Allison Reserve,Akatore, Dunedin, SO). Scale bar = 1.0 mm.

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 12. Digital images of pronota of New Zealand Nesamblyops species, dorsal aspect. A—N. canaanensis (Canaan, Nelson, SO), B—N. disjunctus (Fletchers Creek, Buller, SO), C—N. hobbit (9mi. N Karamea, Nelson, SO), D—N. karamea (Karamea River Gorge, Nelson, SO), E—N. kuscheli (Flora Hut, Mount Arthur, Nelson, SO), F—N. magnificus (Allison Reserve, Akatore, Dunedin, SO), G—N. montanus (Lake Sylvester, Kahurangi National Park, Nelson, SO), H—N. moorei (Kangaroo Creek, Mawhera Forest, Buller, SO), I—N. ovipennis (Mount Arthur, Nelson, SO). Scale bar = 0.2 mm.

FIGURE 14. Line drawings of male genitalia of New Zealand Nesamblyops species. N. canaanensis (Canaan, Nelson, SO): A—left paramere, left lateral aspect, B—right paramere, right lateral aspect, C—median lobe, right lateral aspect. N. disjunctus (Fletchers Creek, Buller, SO): D—left paramere, left lateral aspect, E—right paramere, right lateral aspect, F—median lobe, right lateral aspect. N. hobbit (Mount Domett, Nelson, SO): G—left paramere, left lateral aspect, H—right paramere, right lateral aspect, I—median lobe, right lateral aspect. N. karamea (Karamea River Gorge, Nelson, SO): J—left paramere, left lateral aspect, K—right paramere, right lateral aspect, L—median lobe, right lateral aspect. N. kuscheli (Flora Hut, Mount Arthur, Nelson, SO): M—left paramere, left lateral aspect, N—right paramere, right lateral aspect, O—median lobe, right lateral aspect. N. magnificus (Allison Reserve, Akatore, Dunedin, SO): P—left paramere, left lateral aspect, Q—right paramere, right lateral aspect, R—median lobe, right lateral aspect. Legend: rCs—reversed C-contour; Vs—V-contour. 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 19. 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. canaanensis; black circles—N. hobbit; blue circles— N. ovipennis; yellow circles—N. karamea; red circles—N. kuscheli. Scale bar = 0.5 mm.