Trichotichnus (Neotichnus) bellorum, 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 : 376-378

Trichotichnus (Neotichnus) bellorum Kataev, sp.n.

Figs 1–10 , 31 .

MATERIAL. Holotype: ♂, “ Papua New Guinea / Wau–Mt. Missim / Apr. 2–3.1982 / Coll. R. & J. Bell / 1980–2000 m ” ( UVM). Paratype: ♂, “ Papua New Guinea / Wau — Mt. Missim / Mar. 26– 28.1982 / Coll. R.T. Bell / 1950 m ” ( ZSM) .

DESCRIPTION (male). Body length 6.9–7.3 mm. Habitus as in Fig. 1 .

Dorsal side of body dark brown, moderately shiny, not iridescent, with labrum, narrow pronotal and elytral lateral margins reddish brown; ventral side reddish dark brown, elytral epipleurae reddish brown. Palpi, antennae and legs yellowish brown.

Head large, in lateral view ( Fig. 2 ) almost as thick as prothorax, in dorsal view a little narrower than pronotum (HWmax/PWmax 0.75–0.76, HWmin/PWmax0.62–0.63), very finely micropunctate on frons and vertex. Eyes small and weakly convex (HWmax/HWmin 1.20–1.21), in lateral view oval, separated from buccal fissure ventrally by distance about half diameter of eye. Genae glabrous. Tempora slightly oblique, almost flat, glabrous. Fronto-clypeal suture fine, shallow, slightly angulate medially. Frontal foveae wide oval, shallow. Fronto-ocular furrows very short and indistinct. Supraorbital furrows very narrow, touching upper edge of eye, not widened posteriorly. Supraorbital setigerous pores small, situated behind level of posterior edge of eye and removed from supraorbital furrows by distance greater than diameter of eye. Labrum moderately concave anteriorly. Clypeus slightly convex, arcuately emarginate along anterior margin, with a pair of setigerous pores each located at anterior angle. Mentum ( Fig. 4 ) completely fused with submentum, with prominent median tooth; epilobes very narrow; submentum with one pair of long setae. Ligular sclerite narrow, almost parallel-sided, truncate at apex, with one pair of ventroapical setae; ventroapical setigerous pores attaching lateral margins of ligular sclerite. Paraglossae wide, rounded apically, markedly longer than ligular sclerite and separated from it by very narrow notches. Penultimate labial palpomere about as long as ultimate palpomere, with two long and three or four short setae on anterior (inner margin). Left mandible sharply bent apically, with a tip in frontal view narrow, subtruncate. Dorsal microsculpture very distinct throughout, consisting of more or less isodiametric meshes. Antennae pubescent from half of antennomere 3, short, not reaching pronotal basal edge, with antennomeres 5– 8 wide, about 1.4–1.5 times as long as wide. Basal antennomere almost as long as antennomere 3.

Pronotum moderately transverse (PWmax/PL 1.38–1.41), widest at end of anterior third, approximately equally narrowed apically and basally (PWmax/PWmin-bas 1.32–1.33; PWmax/ PWmin-ap 1.32–1.34), with one lateral seta inserted before widest point. Sides rounded anteriorly, sinuate in basal quarter; lateral bead very narrow throughout, reaching basal margin. Apical margin moderately emarginate, almost straight in middle portion, very narrowly bordered laterally. Apical angles acutangular, blunted at tip, slightly protruded ahead, without setae. Basal margin slightly rounded in middle portion, oblique laterally, not bordered, about as long as 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. Lateral gutters narrow in apical twothirds, slightly widened in basal third, reaching basal pronotal edge. Basal foveae small, elongate, vaguely outlined; area between them and lateral pronotal edge flattened; pronotal base not depressed medially. Median line superficial, short, not reaching apical and basal margins. Anterior transverse depression very shallow or indistinct. Surface very finely and indistinctly punctate laterobasally. Microsculpture present throughout, slightly finer than that on head, consisting of isodiametric meshes along margins and of short transverse meshes in middle.

Elytra convex, steeply declined to apex, oval (EL/EW 1.27–1.30; EL/PL 2.24–2.29; EW/PWmax 1.25–1.27), widest behind middle; sides almost rectilinearly diverging before middle. Humeri prominent, angulate, without denticle at tip. Subapical sinuation very shallow, indistinct. Sutural angle narrowly rounded at tip. Basal edge almost evenly arched, forming an almost right or slightly obtuse angle (internal humeral angle) with lateral margin. Striae fine, slightly crenulate, slightly impressed along entire length; striae 5–7 not reaching anteriorly basal edge. Intervals slightly convex, moderately narrowed apically, impunctate. Parascutellar (abbreviate) striole very short or absent ( Fig. 3 ); basal setigerous pore present, comparatively large, slightly distant from basal elytral edge; interval 2 with very short additional striole basally. Interval 3 without discal setigerous pore. Lateral groove flat throughout or with short elongate convexity along this groove apically forming a short additional interval. Marginal umbilicate series without distinct gap at middle, consisting of 15–17 setigerous pores. Microsculpture on intervals distinct, consisting of almost isodiametric meshes basally and of short transverse meshes on remaining surgace.

Wings reduced to small scales.

Thoracic sternites, including prosternum, impunctate and glabrous. Prosternal process with moderately long setae at apex. Metepisternum ( Fig. 5 ) markedly wider than long, slightly narrowed posteriorly.

Legs relatively short. Metacoxae with an additional posteromedial seta. Pro- and mesofemora with 3–4 setae along lower margin. Metafemur ventrally with two setae at posteri- or margin and without setae at anterior margin; no seta on anterior margin preapically. Protibia on dorsal side without longitudinal sulcus, with three preapical spines (one or two distant spines stouter than other) on outer margin. Tarsi glabrous dorsally; tarsomere 5 with two pairs of ventro-lateral setae. Metatarsus short, much shorter than HWmin, with tarsomeres 2–4 short, markedly widened distally; metatarsomere 1 moderately widened distally, slightly shorter than metatarsomeres 2 and 3 combined; metatarsomeres 1–4 sparsely setose ventrally. Protarsomeres 1–4 and mesotarsomeres 2–4 (in male) widened and with adhesive biseriate scales ventrally, comparatively short; mesotarsomere 1 slightly shorter than mesotarsomeres 2 and 3 combined.

Abdominal sternites without additional setae; last visible abdominal sternite (VII) (in male) rounded at apex, with two pairs of marginal setae (these setae not distant from margin) ( Fig. 6 ).

Parameres ( Figs 7–8 ) medium sized. Median lobe of aedeagus ( Figs 9–10 ) in lateral view arcuate along dorsal side, with ventral margin slightly convex behind middle, and with apex forming a small oblique capitulum; terminal lamella in dorsal view short and very narrow, narrowed posteriorly. Apical orifice shifted to left, wide apically. Internal sac without spines, with two parallel spiny patches basally (well visible in dorsal view).

ETYMOLOGY. Named after the collectors of this new species, Ross and Joyce Bell, the famous American coleopterologists who made a significant contribution to the morphology and taxonomy of beetles, especially Rhysodidae .

COMPARISON. Within the subgenus, T. bellorum sp.n. is easily recognizable by the impunctate head and pronotum. See also the “Comparison” section under T. riedeli Kataev, sp.n.

DISTRIBUTION ( Fig. 31 ). Found in the southeastern part of Papua New Guinea, Morobe Province, on the Mount Missim , at altitudes of about 1500–2000 m .

Figures

Figs 1–3. Trichotichnus (Neotichnus) bellorum sp.n.: 1 — general habitus, dorsal view; 2 — fore-body, lateral view; 3 — elytral base; a.s. — additional striole, p.s.s. — parascutellar striole. Scale bars: 1.0 mm. Рис. 1–3. Trichotichnus (Neotichnus) bellorum sp.n.: 1 — внешний вид, сверху; 2 — голова и грудь, сбоку; 3 — основание надкрылий; a.s. — дополнительнаЯ бороЗдка, p.s.s. — приЩитковаЯ бороЗдка. Масштаб: 1,0 mm.

Figs 4–10. Trichotichnus (Neotichnus) bellorum sp.n.: 4 — labium; 5 — left metepisternum; 6 — apex of male last abdominal sternite; 7 — left paramere; 8 — right paramere; 9–10 — median lobe of aedeagus; 4–6 — ventral view; 7–9 — lateral view; 10 — dorsal view. Scale bars: A = 0.5 mm (4–6), B = 1.0 mm (7–10). Рис. 4–10. Trichotichnus (Neotichnus) bellorum sp.n.: 4 — нижнЯЯ губа; 5 — левый метЭпистерн; 6 — вершина последнего брюшного стернита; 7 — леваЯ парамера; 8 — праваЯ парамера; 9–10 — срединнаЯ лопасть Эдеагуса; 4–6 —сниЗу; 7–9 — сбоку; 10 — сверху. Масштаб: A = 0,5 mm (4–6), B = 1,0 mm (7–10).

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