Nesamblyops lescheni, 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 : 187-188

Nesamblyops lescheni , sp. nov.

Figs. 2E , 4E , 5M–O , 7E , 8B , 10

Type material. HOLOTYPE, male, in NZAC, labeled: \ E. Attempt Hill, D’Urville Isd. 28-9-63 Litter J.I.Townsend \ J.I.Townsend Collection \ Nesamblyops oreobius (Broun) Det. I.Townsend \. PARATYPES (13 specimens, in NZAC, dissected 1 male and 1 female) , 1 male and 11 females labeled same as holotype; 1 female labeled: \ Coll. A.C.O’Connor, October, 1942 \ D’Urville Is. Cook Strait, N.Z. \ A.E. Brookes Collection \ DSIR \ No \ NZ PB \.

Etymology. The specific epithet is a Latinized eponym in the genitive case and is based on the surname of Richard A.B. Leschen, New Zealand coleopterist ( New Zealand Arthropod Collection, Maanaki Whenua—Landcare Research, Auckland, New Zealand), who made material of New Zealand Anillini available for this study.

Type locality. New Zealand, South Island , Marlborough Sounds, D’Urville Island .

Recognition. Adults of this species ( Fig. 2E ) can be distinguished from adults of many Nesamblyops species (cf. with Figs. 2A–C , 3A–C ) by their smaller size and characteristic body proportions, as well by the structure of the male genitalia.

Description. Of moderate size for genus (SBL range 1.43–1.68 mm, mean 1.54± 0.091 mm, n=12).

Habitus. Body form ( Fig.2E ) markedly convex, elongate ovoid, general proportions wide (WE/SBL 0.42±0.013), head narrow relative to pronotum (WH/WPm 0.69±0.013), proportions of pronotum in comparison to elytra average for genus (WPm/WE 0.77±0.034).

Color. Body color brunneorufous, appendages testaceous.

Prothorax. Pronotum ( Fig. 4E ) moderately long in comparison to elytra (LP/LE 0.43±0.024) and moderately transverse (WPm/LP 1.28±0.037), with lateral margins arcuately constricted posteriorly (WPm/WPp 1.29±0.027). Anterior angles indistinct, posterior angles obtuse (106–115°), but distinct. Width between posterior angles greater than between anterior angles (WPa/WPp 0.89±0.015). Basal margin almost rectilinear, slightly convex at middle.

Elytra. Ovoid, narrowly depressed along suture, comparatively long (LE/SBL 0.58±0.012) and wide (WE/LE 0.72±0.021). 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. 5O ) slightly arcuate and moderately twisted. Shaft subparallel, tapering in apical third. Apex short and semicircular. Apical orifice short, occupies about one third of the shaft length. Ventral margin of median lobe widely concave. Walls of shaft with numerous poriferous canals. 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. 5M ) comparatively wide, with shortly attenuate apex, bearing three long setae. Right paramere ( Fig. 5N ) short and wide, bearing three long setae, which are slightly longer the length of paramere. Ring sclerite as in Fig. 7E .

Female internal genitalia. Spermatheca ( Fig. 8B ) sclerotized, of bulb-like shape with wider rounded apical part and narrower rounded 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 known only from the D’Urville Island in the Marlborough Sounds area ( Crosby et al. 1998) ( Fig. 10 , red circles). Possibly, N. lescheni is an endemic of this island.

Habitat. Labels do not include specific information about habitats.

Relationships. The structure of the male genitalia suggests relationship of N. lescheni to other species with similar V-shaped structure of dorsal copulatory sclerites in the internal sac of the median lobe, such as N. confusus and N. oreobius .

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 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 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.