Ctenognathus tawanui Larochelle and Larivière, 2021

Larochelle & Larivière, Marie-Claude, 2021, Synopsis of the tribe Platynini in New Zealand (Coleoptera: Carabidae), Insecta Mundi 2021 (864), pp. 1-96 : 42-43

Ctenognathus tawanui Larochelle and Larivière , new species

Fig. 63 , 106 , 145

Ctenognathus tawanui Larochelle and Larivière , new species. Holotype: male (NZAC) labeled “ NEW ZEALAND SL Catlins SFP, Catlins Riv Walk (Frank Stm-Tawanui Cpgd) 100m 12.I.1999 Larivière, Larochelle[,] Paquin, Dupérré (typed) / Wet beech forest along stream banks - under logs. (typed) / HOLOTYPE [male symbol] Ctenognathus tawanui Larochelle & Larivière, 2021 (red label; typed).” Paratypes: one male (LUNZ) from the same locality as the holotype and one female (NZAC) from Catlins State Forest Park , Catlins River Walk , Wallis Stream-Frank Stream (SL), bearing blue paratype labels.

Description. Body length 7.0– 9.8 mm. Head, pronotum, and elytra black; abdomen piceous black; antennal segments 1–3 dark rufous, 4–11 rufotestaceous; palpi reddish; legs black. Microsculpture isodiametric on head, moderately transverse on pronotum, and isodiametric on elytra. Iridescence absent. Head and pronotum very shiny, elytra dull. Forebody narrow in comparison to elytra. Head. Moderately wide. Mandibles moderately long and curved anteriorly. Labrum moderately transverse, subtruncate anteriorly. Eyes strongly convex; two setiferous punctures on inner side of each eye. Tempora not inflated. Neck constriction shallow dorsolaterally. Mentum: medial tooth moderately emarginate apically; two setae. Submentum with four setae. Palpi with terminal segment truncate apically. Thorax. Pronotum slightly convex, impunctate, obsoletely wrinkled on disc, narrow, moderately cordate, widest before middle; apex strongly emarginate; anterolateral angles poorly developed, broadly rounded; anterior bead complete; sides strongly rounded, moderately sinuate posteriorly; lateral beads complete; lateral depressions narrow anteriorly, widened posteriorly; two setiferous punctures (anterior and posterior) on each side; posterolateral angles rectangular; laterobasal foveae very deep, moderately wide, prolonged forward; posterior bead incomplete, obsolete medially; base subtruncate. Legs. Short. Metafemora with two posteroventral setae. Meso- and metatarsomeres 1–4 well developed, tricarinate dorsally, deeply bisulcate laterally. Metatarsomeres 4 moderately bilobed, symmetrical apically. Metatarsomeres 5 glabrous ventrally. Elytra. Moderately convex, sloping down toward apex, oblong, widest behind middle. Shoulders moderately rounded. Sides strongly rounded. Scutellar setiferous pore invisible. Scutellar striole moderately long, impunctate. Striae shallow, finely punctate. Intervals subdepressed; interval 3 with three very deep, large (foveate) setiferous punctures. Umbilicate series with 13–15 setiferous punctures. Subapical sinuations strong. Apices obtuse. Abdomen. Sterna IV–VI: both sexes with two long apical ambulatory setae. Sternum VII (last visible sternum): male with two long apical ambulatory setae; female with four long apical ambulatory setae. Aedeagus. Lateral view ( Fig. 106 ): moderately arcuate; base moderately convex dorsally, with basal lobe moderately wide; middle moderately biconvex dorsally, moderately concave ventrally, with dorsal membranous area moderately wide and long; apex strongly convex dorsally, straight ventrally, with extreme tip moderately wide and moderately long. Dorsal view: moderately wide, asymmetrical (ostium of membranous area deflected to the left); basal bulb moderately distant from membranous area.

Material examined. 12 specimens ( JNNZ, LUNZ, NZAC).

Geographic distribution ( Fig. 145 ). South Island: SL–Catlins State Forest Park (Catlins River Track (Frank Stream to Tawanui Campground; Wallis Stream to Frank Stream); Lake Wilkie; Slopedown Range, North of Slopedown Hill).

Ecology. Lowland. Epigean. Wet forests (podocarp, broadleaf, beech), swamp forests, and tree plantations (pine). Associated with streams and mud flats. Shaded ground; wet soil. Nocturnal; hides during the day under logs, fallen branches, and stones.

Biology. Seasonality: January–February. Predacious (based on mouthpart morphology).

Dispersal power. Subapterous (incapable of flight). Moderate runner.

Collecting techniques. Turning logs, fallen branches, and stones; pitfall trapping.

Remarks. The species is named after Tawanui (SL), the place in the Catlins closest to the type locality, and is applied as a noun in apposition. In addition to diagnostic characters of the male genitalia, Ctenognathus tawanui has the following distinguishing features: elytra without visible scutellar setiferous pore; head, pronotum, elytra, and abdomen black; antennal segments 1–3 dark rufous, 4–11 rufotestaceous; legs short, black; rather small in size, body length 7.0– 9.8 mm. Ctenognathus tawanui is restricted to the southern South Island (SL).

Figures

Figures 61–64. Dorsal habitus. 61) Ctenognathus adamsi. 62) C. pictonensis. 63) C. tawanui new species. 64) C. perumalae new species. Scale line = 1 mm.

Figures 101–107. Aedeagus, lateral. 101) Ctenognathus tepaki new species. 102) C. urewera new species. 103) C. cardiophorus. 104) C. adamsi. 105) C. pictonensis. 106) C. tawanui new species. 107) C. perumalae new species.

Figures 142–147. Species distribution maps. 142) Ctenognathus pictonensis. 143) C. sandageri. 144) C. takahe new species. 145) C. tawanui new species. 146) C. tepaki new species. 147) C. urewera new species.