Ctenognathus perumalae Larochelle and Lariviere E 2021, new species

Fig. 64, 107, 141

Ctenognathus perumalae Larochelle and Larivière, new species. Holotype: male (NZAC) labeled “[NEW ZEALAND WD] Okarito 17.11.56 B.B. Given (hand-written) / HOLOTYPE [male symbol] Ctenognathus perumalae Larochelle & Larivière, 2021 (red label; typed).” Paratypes: two females (AMNZ, NZAC) from the same locality as the holotype, bearing blue paratype labels.

Description. Body length 11.9–12.4 mm. Head, pronotum, elytra, and abdomen piceous black; antennae and palpi dark rufous; legs black. Microsculpture isodiametric on head, very transverse (with microlines) on pronotum, and isodiametric (almost granulate) on elytra. Iridescence absent. Head, pronotum, and elytra very shiny. Forebody moderately wide in comparison to elytra. Head. Moderately wide. Mandibles moderately long and curved anteriorly. Labrum strongly transverse, moderately emarginate anteriorly. Eyes moderately convex; two setiferous punctures on inner side of each eye. Tempora not inflated. Neck constriction absent dorsolaterally. Mentum: medial tooth subtruncate apically; two setae. Submentum with six setae. Palpi with terminal segment obtuse apically. Thorax. Pronotum strongly convex, impunctate, unwrinkled, wide, strongly cordate, widest before middle; apex moderately emarginate; anterolateral angles moderately developed, obtuse; anterior bead complete; sides strongly rounded and sinuate posteriorly; lateral beads complete; lateral depressions wide; two setiferous punctures (anterior and posterior) on each side; posterolateral angles rectangular; laterobasal foveae very deep and wide, prolonged forward; posterior bead incomplete, obsolete medially; base emarginate. Legs. Moderately long. 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. Strongly convex, sloping toward apex, subovate, widest about middle. Shoulders obtuse. Sides moderately rounded. Scutellar setiferous pore visible. Scutellar striole moderately long, impunctate. Striae deep, impunctate. Intervals strongly convex; interval 3 with three or four moderately deep, small setiferous punctures. Umbilicate series with 17–18 setiferous punctures. Subapical sinuations strong. Apices obtusely rounded. Abdomen. Sterna IV–VI: both sexes with two long apical ambulatory setae. Sternum VII (last visible sternum): male with four long apical ambulatory setae; female with eight long apical ambulatory setae. Aedeagus. Lateral view (Fig. 107): moderately arcuate, slender; base moderately convex dorsally, with basal lobe moderately wide; middle subparallel dorsally, moderately concave ventrally, with dorsal membranous area moderately widened in apical half and moderately long; apex slightly convex dorsally, slightly concave ventrally, with extreme tip wide, subtriangular, short. Dorsal view: moderately wide, asymmetrical (ostium of membranous area deflected to the left); basal bulb moderately distant from membranous area.

Material examined. 26 specimens (AMNZ, JNNZ, LUNZ, MONZ, NZAC).

Geographic distribution (Fig. 141). South Island: WD –Fox Glacier. Franz Josef (Alex Knob; Callary Gorge; Lake Wombat track). Karangarua River. Macdonalds Creek (north of Franz Josef). Okarito. Taumaka Island (Taumaka Forest).

Ecology. Lowland, montane. Epigean. Wet forests (broadleaf). Shaded ground; wet soil. Nocturnal; found during the day under a stone and in a fallen tree.

Biology. Seasonality: September, November–April. Tenerals: November, February. Predacious (based on mouthpart morphology).

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

Collecting techniques. Turning stones and fallen trees.

Remarks. The species is named after Dr. Divya Perumal (Eye Institute, Auckland), a special acquaintance and a highly skilled health specialist, someone who handles challenges with grace. In addition to diagnostic characters of the male genitalia, Ctenognathus perumalae has the following distinguishing features: pronotum strongly cordate; elytra subovate, strongly convex, widest about middle. Ctenognathus perumalae is restricted to the southwestern South Island (southern WD).