Nesamblyops pygmaeus, Sokolov, 2025

Sokolov, Igor M., 2025, Three new blind species of the genus Nesamblyops Jeannel, 1937 (Anillini: Carabidae: Coleoptera) from New Zealand, Zootaxa 5566 (1), pp. 52-60 : 58

Nesamblyops pygmaeus , sp. nov.

Figures. 1C , 2C , 3G–I , 4

HOLOTYPE, male, in NZAC, labeled: \ 1310 \ New Zealand WN 4km along Waiotauru Rd Tararua FP 16/11/91 \ In soil sample in Nothofagus forest \.

Etymology. The specific epithet is a Latin adjective, pygmaea (meaning “dwarf”) in the masculine form and refers to the small size of the male specimen.

Type locality. New Zealand, North Island, WN, Tararua Range at south-eastern part of Kāpiti Coastal District.

Recognition. Adults of this species ( Fig. 1C ) can be distinguished from other blind Nesamblyops species described here by the well-developed microsculpture on the frons of the head and disc of the pronotum, and by the structure of the male genitalia.

Description. Small for genus (SBL of Holotype = 1.46 mm).

Habitus. Body form ( Fig. 1C ) slightly convex, elongate ovoid, general proportions moderately narrow (WE/ SBL 0.39), head moderately wide relative to pronotum (WH/WPm 0.78), proportions of pronotum in comparison to elytra slightly narrow for genus (WPm/WE 0.71).

Color. Body color brunneorufous, appendages testaceous.

Microsculpture. Mesh pattern of irregularly isodiametric sculpticells distinctly present over dorsal surface of head and pronotum.

Prothorax. Pronotum ( Fig. 2C ) moderately long in comparison to elytra (LP/LE 0.41) and slightly transverse (WPm/LP 1.14), with lateral margins rectilinear and strongly constricted posteriorly (WPm/WPp 1.69). Anterior angles indistinct, posterior angles strongly obtuse (148°), completely rounded. Width between anterior angles greater than between posterior angles (WPa/WPp 1.26). Basal margin slightly convex.

Elytra. Ovoid, widely depressed along suture, comparatively long (LE/SBL 0.58) and moderately narrow (WE/ LE 0.66). Humeri completely rounded. Lateral margins slightly divergent at basal half, shortly subparallel at middle and evenly rounded to apex in apical half.

Male genitalia. Median lobe of aedeagus ( Fig. 3I ) moderately arcuate and slightly twisted. Shaft subparallel at basal two thirds, tapering in apical third. Apex small, straight, with narrowly rounded tip. Apical orifice of moderate length, occupies apical third of shaft length. Ventral margin of median lobe slightly curved downward. Walls of shaft without poriferous canals. Copulatory sclerites well-developed, moderately sclerotized, represented by V-contour with long dorsal branch and large medial rC-sclerite. Sclerotized membranous fields absent. Left paramere ( Fig. 3G ) of moderate length, with attenuated apex, bearing two long setae. Right paramere ( Fig. 3H ) long, narrow, bearing two long setae, which are shorter the length of paramere. Ring sclerite not examined.

Female internal genitalia. Spermatheca not examined.

Geographical distribution. The only known locality of the species is in the southern part of the North Island in the Tararua Range within the boundaries of the Tararua Forest Park and the Kāpiti Coastal District ( Fig. 4 , black circle).

Habitat. The holotype, is the only known specimen, and was collected using a washing technique from soil sample taken in Nothofagus forest.

Relationships. The structure of the male genitalia of N. pygmaeus suggests its relatedness to the main pool of the Nesamblyops species with developed V-contour and rC-sclerite in the internal sac of median lobe. Among blind representatives of the genus the configuration of copulative sclerites of N. pygmaeus suggests its remote relatedness to N. larochellei , but not to N. nunni .

Figures

FIGURE 1. Digital habitus images of blind Nesamblyops species, dorsal aspect. A—N. nunni (Old Man Range, Central Otago, South Island), B—N. larochellei (Lewis Pass, Buller, South Island), C—N. pygmaeus (Waiotauru Road, Tararua Forest Park, Wellington, North Island). Scale bar 1.0 mm.

FIGURE 2. Digital images of pronota of blind Nesamblyops species, dorsal aspect. A—N. nunni (Old Man Range, Central Otago, South Island), B—N. larochellei (Lewis Pass, Buller, South Island), C—N. pygmaeus (Waiotauru Road, Tararua Forest Park, Wellington, North Island). Scale bar 0.1 mm.

FIGURE 3. Line drawings of male genitalia of blind Nesamblyops species. N. nunni (Old Man Range, Central Otago, South Island): A—left paramere, left lateral aspect, B—right paramere, right lateral aspect, C—median lobe, right lateral aspect. N. larochellei (Lewis Pass, Buller, South Island): D—left paramere, left lateral aspect, E—right paramere, right lateral aspect, F—median lobe, right lateral aspect. N. pygmaeus (Waiotauru Road, Tararua Forest Park, Wellington, North Island): G—left paramere, left lateral aspect, H—right paramere, right lateral aspect, I—median lobe, right lateral aspect. Scale bar 0.1 mm.

FIGURE 4. Distribution records for the blind Nesamblyops species and images of the male median lobe obtained from the collected specimens (inset illustrates specimen localities). Black circle—N. pygmaeus; red circle—N. larochellei; orange circles—N. nunni. Scale bar 0.1 mm.