Ctenognathus otagoensis ( Bates, 1878 )

Larochelle & Larivière, Marie-Claude, 2021, Synopsis of the tribe Platynini in New Zealand (Coleoptera: Carabidae), Insecta Mundi 2021 (864), pp. 1-96 : 54-56

Ctenognathus otagoensis ( Bates, 1878)

Fig. 74 , 118 , 140

Anchomenus (Platynus) otagoensis Bates, 1878: 27 . Syntypes: “[male symbol] [female symbol]” from [CO/DN/OL] “ Otago ” (could not be located either in MNHN or in CMNZ).

Anchomenus otagoensis: Broun 1880: 25 .

Agonum (Platynus) otagoense: Csiki 1931: 853 .

Platynus otagoensis: Liebherr and Zimmerman 1998: 147 .

Ctenognathus otagoensis: Liebherr 2005: 283 .

Description. Body length 10.3–12.7 mm. Head, pronotum, and elytra piceous black; abdomen rufopiceous; antenna and palpi rufotestaceous; femora and tibiae pale yellow; tarsi reddish. Microsculpture isodiametric on head, pronotum, and elytra (elytra almost granulate). Iridescence absent. Head and pronotum very shiny, elytra dull. Forebody moderately wide 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 absent dorsolaterally. Mentum: medial tooth slightly or moderately emarginate apically; two setae. Submentum with six setae. Palpi with terminal segment obtuse apically. Thorax. Pronotum slightly convex, impunctate, obsoletely wrinkled on disc, wide, moderately cordate, widest before middle; apex slightly emarginate; anterolateral angles poorly developed, obtuse; anterior bead incomplete, obsolete medially; sides moderately rounded, slightly 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 moderately deep and wide, prolonged forward; posterior bead complete; base truncate. 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. Subdepressed, not sloping down toward apex, oblong, widest about middle. Shoulders moderately rounded. Sides moderately rounded. Scutellar setiferous pore visible. Scutellar striole moderately long, impunctate. Striae shallow, finely punctate. Intervals depressed; interval 3 with three shallow, minute setiferous punctures. Umbilicate series with 17–20 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. 118 ): strongly arcuate, strongly widened medially; base strongly convex dorsally, with marginal blade instead of basal lobe; middle strongly convex dorsally, slightly convex ventrally, with dorsal membranous area strongly widened in apical half and moderately long; apex strongly convex dorsally, moderately concave ventrally, with extreme tip narrow and very long. Dorsal view: moderately wide, asymmetrical (ostium of membranous area deflected to the left); basal bulb moderately distant from membranous area.

Material examined. 615 specimens ( AMNZ, JNNZ, LUNZ, MONZ, NZAC).

Geographic distribution ( Fig. 140 ). South Island: CO, DN, FD, OL, SL.

Ecology. Lowland, montane, subalpine. Epigean. Wet forests (beech, broadleaf), tree plantations (pine), shrublands, and scrublands. Associated with streams. Shaded ground; wet soil. Nocturnal; hides during the day under logs, fallen trees, and stones. Gregarious.

Biology. Seasonality: September–April, June, August. Tenerals: March. Predacious (based on mouthpart morphology). Occasionally infested with fungi (Laboulbeniales).

Dispersal power. Subapterous (incapable of flight). Moderate runner. Occasional climber (on trees).

Collecting techniques. Pitfall trapping; turning logs, fallen trees, and stones.

References. Larochelle and Larivière 2001: 131 (as “ Anchomenus ” otagoensis ; catalogue; biology, dispersal power, ecology, geographic distribution, references); Liebherr 2005: 283 (as Ctenognathus otagoensis ); Larochelle and Larivière 2007: 111 (list), 2016: 37 (list).

Remarks. The syntypes of Anchomenus otagoensis could not be located either in MNHN or in CMNZ where Bates’ specimens can usually be found. However, there is no ambiguity regarding the identity of this taxon; the original description can only apply to the species as currently understood. In addition to diagnostic characters of the male genitalia, Ctenognathus otagoensis has the following distinguishing features: pronotum slightly cordate;

elytra subdepressed, striae finely punctate; eyes strongly rounded; terminal segment of palpi obtuse apically. This species occurs in southern areas of the South Island (OL–DN to FD–SL).

Figures

Figures 73–76. Dorsal habitus. 73) Ctenognathus intermedius. 74) C. otagoensis. 75) C. colensonis. 76) C. earlyi new species. Scale line = 1 mm.

Figures 115–122. Aedeagus, lateral. 115) Ctenognathus xanthomelus. 116) C. intermedius. 117) C. colensonis. 118) C. otagoensis. 119) C. earlyi new species.120) C. davidsoni new species.121) C. oreobius. 122) C. hoarei new species.

Figures 136–141. Species distribution maps. 136) Ctenognathus kaikoura new species. 137) C. marieclaudiae new species. 138) C. novaezelandiae. 139) C. oreobius. 140) C. otagoensis. 141) C. perumalae new species.