Trichotichnus (Neotichnus) riedeli, Kataev, 2022

Kataev, B. M., 2022, Description of two new subgenera of Trichotichnus, with new brachypterous species from New Guinea and Sumatra (Coleoptera: Carabidae), and notes on three previously described species, Russian Entomological Journal 31 (4), pp. 373-384 : 378-380

Trichotichnus (Neotichnus) riedeli Kataev, sp.n.

Figs 11–16 , 31 .

MATERIAL. Holotype: ♀, “ Papua N. G. / Morobe Prov. / leg. A. Riedel ”, “ca. 10 km S Garaina , / Saureri, 1800–2150 m, / 26.III.1998 ” ( ZSM).

DESCRIPTION (female). Body length 7.3 mm. Habitus as in Fig. 11 .

Head and pronotum black, with labrum, wide pronotal medioapical and mediobasal margins and very narrow lateral margins brown; elytra brown, with brownish yellow sutural intervals; thoracic and ventral sternites blackish brown. Palpi, antennae and legs yellowish brown.

Head large, in lateral view ( Fig. 12 ) almost as thick as prothorax, in dorsal view a little narrower than pronotum (HWmax/PWmax 0.77, HWmin/PWmax 0.64), somewhat coarsely punctate on frons and vertex. Eyes small and weakly convex (HWmax/HWmin 1.20), in lateral view oval, separated from buccal fissure ventrally by distance about diameter of eye. Genae glabrous. Tempora oblique, almost flat, glabrous. Fronto-clypeal suture fine, shallow, slightly angulate medially. Frontal foveae small and shallow.Fronto-ocular furrows present, very shallow, reaching about half distance to eye. Supraorbital furrows very narrow, touching upper edge of eye, not widened posteriorly. Supraorbital setigerous pores comparatively large, situated behind level of posterior edge of eye and removed from supraorbital furrows by distance about diameter of eye. Labrum moderately concave anteriorly. Clypeus slightly convex medially, arcuately emarginate along anterior margin, with a pair of setigerous pores each located at anterior angle. Mentum ( Fig. 14 ) fused with submentum (traces of suture recognizable medially), with prominent acute median tooth; epilobes very narrow; submentum with one pair of long setae. Ligular sclerite wide, not widened apically, with truncate apex and with one pair of ventroapical setae; ventroapical setigerous pores attaching lateral margins of ligular sclerite. Paraglossae wide, angularly rounded apically, slightly longer than ligular sclerite and separated from it by very narrow notches. Penultimate labial palpomere about as long as ultimate palpomere, with two longer and one shorter setae on anterior (inner) margin. Left mandible sharply bent apically, with a tip in frontal view narrow, slightly blunted. Dorsal microsculpture distinct throughout, consisting of more or less isodiametric meshes. Antennae pubescent from half of antennomere 3, short, slightly not reaching pronotal basal edge, with antennomeres 5–8 wide, about 1.4 times as long as wide. Basal antennomere almost as long as antennomere 3.

Pronotum slightly transverse (PWmax/PL 1.23), widest at end of anterior third, a little more strongly narrowed apically than basally (PWmax/PWmin-bas 1.26; PWmax/ PWmin-ap 1.39), with one lateral seta inserted before widest point. Sides rounded anteriorly, sinuate in basal quarter; lateral bead very narrow, scarcely widened before basal angles, reaching basal margin. Apical margin almost straight, very narrowly and finely bordered throughout. Apical angles rounded at tip, only scarcely protruded ahead, without setae. Basal margin widely rounded in middle portion, oblique laterally, not bordered, slightly longer than apical margin and markedly shorter than base of elytra between humeral angles. Basal angles obtuse, slightly blunted at tip. Disc rather convex, strongly sloping to apical angles and laterally. Lateral gutters narrow, moderately widened in basal quarter, reaching basal pronotal edge and forming basally comparatively narrow laterobasal depression. Basal foveae small and very shallow, indistinct; area between narrow laterobasal depressions convex. Median line superficial, short, not reaching apical and basal margins. Anterior transverse depression very shallow, indistinct. Surface comparatively coarsely and densely punctate throughout. Microsculpture present throughout, consisting of short transverse meshes.

Elytra convex, steeply declined to apex, oval (EL/EW 1.40; EL/PL 2.09; EW/PWmax 1.22), widest at middle; sides very slightly sinuate before middle. Humeri prominent, angulate, with a tiny acute denticle at tip visible when viewed from behind. Subapical sinuation very shallow. Sutural angle rounded at tip. Basal edge almost evenly arched, forming a slightly obtuse angle (internal humeral angle) with lateral margin. Striae slightly crenulate, slightly impressed along entire length; reaching anteriorly basal edge.Intervals weakly convex,moderately narrowed apically,impunctate.Parascutellar (abbreviate) striole short ( Fig. 13 ); basal setigerous pore present, comparatively large, slightly distant from basal elytral edge. Interval 3 without discal setigerous pore.Lateral groove anteriorly flat, posteriorly with elongate convexity along this groove forming an additional interval. Marginal umbilicate series with a gap at middle, consisting of 6 setigerous pores in basal group and of 8 pores in apical group. Microsculpture on intervals distinct throughout, consisting of moderately long transverse meshes.

Wings hightly reduced.

Thoracic sternites, including prosternum glabrous. Prosternal process with moderately long setae at apex. Prosternum, proepisterna, epipleura of pronotum (prohypomera), mesosternum laterally and metepisterna coarsely and sparsely punctate. Metepisternum ( Fig. 15 ) short, about as wide as long, moderately narrowed posteriorly.

Legs relatively short. Metacoxae without posteromedial setigerous pore. Profemur with one seta and mesofemur with two setae along lower margin. Metafemur ventrally with two setae at posterior margin and without setae at anterior margin; one short preapical seta on anterior margin. Protibia on dorsal side without longitudinal sulcus, with three (in female) preapical spines on outer margin. Tarsi short, glabrous dorsally; tarsomere 5 with two pairs of ventro-lateral setae; metatarsus much shorter than HWmin. Pro-, meso- and metatarsomeres 2–4 (in female) very short, markedly widened distally; meso- and metatarsomere 1 moderately widened distally, shorter than corresponding tarsomeres 2 and 3 combined; metatarsomeres 1–4 sparsely setose ventrally.

Abdominal sternites without additional setae; last visible abdominal sternite (VII) (in female) angularly rounded at apex, with two pairs of marginal setae (these setae not distant from margin) ( Fig. 16 ).

ETYMOLOGY. Named after the famous entomologist Alexander Riedel (Karlsruhe), the collector of this new species.

COMPARISON. This new species distinctly differs from T. bellorum sp.n., as well as from most other congeners, in the head and pronotum coarsely punctate. In addition, it differs from the former species in having the metacoxa without a posteromedial setigerous pore, the metepisternum slightly narrower, the head with more distinct fronto-ocular furrows, the more elongate pronotum with apical angles rounded at

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tip, only scarcely protruded ahead, the humeri with a tiny acute denticle at tip, and the pro- and mesofemora on the inner margin with one and two setae, respectively.

In the habitus and the elytra without discal pore, T. riedeli sp.n. is similar to some members of Chydaeus (subtribe Anisodactylina ), however, if males are excluded, their females distinctly differs from the new species at lest in having the paraglossae narrow, removed distally from the ligular sclerite, and the pronotal basal margin distinctly bordered.

DISTRIBUTION ( Fig. 31 ). The single specimen of this new species was collected in the southeastern part of Papua New Guinea, Morobe Province, in 10 km south of Garaina (Saureri), at an altitude of about 1800–2150 m, about 100 km southeast of the locality of T. bellorum sp.n .

REMARKS. Though only one female is available, this species is very dissimilar to other species and easily recognizable based on its external characters.

The female genitalia of T. riedeli sp.n. were not examined because they were not found inside the abdomen. They may have been lost during the preparation and mounting of the specimen.

Figures

Figs 11–13. Trichotichnus (Neotichnus) riedeli sp.n.: 11 — general habitus, dorsal view; 12 — fore body, lateral view; 13 — elytral base. Scale bars: 1.0 mm. Рис. 11–13. Trichotichnus (Neotichnus) riedeli sp.n.: 11 — обЩий вид, сверху; 12 — голова и грудь, сбоку; 13 — основание надкрылий. Масшаб: 1,0 mm.

Figs 14–16. Trichotichnus (Neotichnus) riedeli sp.n.: 14 — labium; 15 — left metepisternum; 16 — apex of female last abdominal sternite. Scale bar: 0.5 mm. Рис. 14–16. Trichotichnus (Neotichnus) riedeli sp.n.: 14 — нижнЯЯ губа; 15 — левый метЭпистерн; 16 — вершина последнего брюшного стернита самки. Масшаб: 0,5 mm.

Fig. 31. Map with localities of Trichotichnus spp. Рис. 31. Карта с местами находок Trichotichnus spp.