Nesamblyops parvulus, 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 : 191-192

Nesamblyops parvulus , sp. nov.

Figs. 3A , 4G , 6A–C , 7F , 10

Type material. HOLOTYPE, male, in NZAC, labeled: \ Mt Stokes 1172m Kenepuru Snds Marlb. 11.x.67 J.McBurney \ moss 67/243 \ DSIR \ Ns \ NZ PB \. PARATYPES (24 specimens, in NZAC, dissected 4 exx.) , 3 males and 6 females labeled same as holotype; 3 males and 8 females labeled: \ Mt Stokes 1160m Marlborough 12 Oct 67 \ J.I.Townsend \ Litter 67/244 \ DSIR \ Ns \ NZ PB \; 1 male: \ Mt Stokes Marlb. 3850’ 12.x.67 J.I.Townsend \ Litter 67/244 \ DSIR \ Ns \ NZ PB \; 1 male and 1 female labeled: \ Mt Stokes 3850’ Marlb. 13.x.67 J.I.Townsend \ Litter 67/245 \ DSIR \ Ns \ NZ PB \; 1 male labeled: \ Mt.Stokes 3850’ 11.x.67 \ Kenepuru Sounds J.I.Townsend \ moss sample 67/243 \.

Etymology. The specific epithet is a Latin adjective, parvulus , in the masculine form, diminutive of Latin parvus meaning “small”, and refers to the small size of the new species.

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

Recognition. Adults of this species ( Fig. 3A ) can be distinguished from adults of many Nesamblyops species (cf. with Figs. 2A–C , 3B–C ) by the small size, elongated habitus, diagnostic shape of pronotum ( Fig. 4G ) as well by the structure of the male genitalia.

Description. Small for genus (SBL range 1.26–1.49 mm, mean 1.37± 0.081 mm, n=15).

Habitus. Body form ( Fig. 3A ) moderately convex, elongate ovoid, general proportions slightly wide (WE/SBL 0.39±0.025), head wide relative to pronotum (WH/WPm 0.75±0.023), proportions of pronotum in comparison to elytra average for genus (WPm/WE 0.74±0.063).

Color. Body color rufotestaceous, appendages testaceous.

Prothorax. Pronotum ( Fig. 4G ) moderately long in comparison to elytra (LP/LE 0.40±0.021) and moderately transverse (WPm/LP 1.23±0.034), with lateral margins arcuately and strongly constricted posteriorly (WPm/WPp 1.37±0.047). Anterior angles indistinct, posterior angles very obtuse (126–141°), almost effaced. Width between anterior angles equals the width between posterior angles (WPa/WPp 1.00±0.047). Basal margin slightly concave.

Elytra. Elongate-ovoid, moderately depressed along suture, comparatively long (LE/SBL 0.60±0.013) and slightly narrow for genus (WE/LE 0.66±0.032). Humeri completely rounded. Lateral margins slightly divergent at basal fourth, subparallel at middle and evenly rounded to apex in apical third.

Male genitalia. Median lobe of aedeagus ( Fig. 6 C ) slightly arcuate and slightly twisted. Shaft diverging basally, tapering in apical half.Apex enlarged with straight rounded tip.Apical orifice long, occupies almost half of the shaft length. Ventral margin of median lobe straight basally, moderately enlarged in apical third. Walls of shaft with few poriferous canals apically. Dorsal copulatory sclerites in form of characteristic U-shaped plate, directed with its open end apically. Scaled membraneous fields lacking. Spines of internal sac absent. Left paramere ( Fig. 6A ) wide, apex blunt, bearing three setae of moderate length. Right paramere ( Fig. 6B ) short and wide, bearing three long setae, which are slightly longer the length of paramere. Ring sclerite as in Fig. 7F .

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 , yellow circle).

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

Relationships. Based on the structure of the male genitalia it is postulated that N. parvulus occupies an isolated position among the examined species of the genus. At Mount Stokes N. parvulus lives in sympatry and syntopically with N. confusus : according to the label data at least one sample included both species.

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 3. Digital images of habitus of New Zealand Nesamblyops species, dorsal aspect. A—N. parvulus (Mount Stokes, Marlborough Sounds, SO), B—N. tararua (Judd Ridge, Tararua Range, Wellington, NO), C—N. townsendi (Tennyson Inlet, Marlborough Sounds, SO). 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 6. Line drawings of male genitalia of New Zealand Nesamblyops species. N. parvulus (Mount Stokes, Marlborough Sounds, SO): A—left paramere, left lateral aspect, B—right paramere, right lateral aspect, C—median lobe, right lateral aspect. N. tararua (Judd Ridge, Tararua Range, Wellington, NO): D—left paramere, left lateral aspect, E—right paramere, right lateral aspect, F—median lobe, right lateral aspect. N. townsendi (Tennyson Inlet, Marlborough Sounds, SO): G—left paramere, left lateral aspect, H—right paramere, right lateral aspect, I—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 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.