Trichotichnus (Pseudotrichotichnus) tenuitibialis, Ito, 2009

Ito, Noboru, 2009, Note on the subgenus Pseudotrichotichnus of the genus Trichotichnus from Southeast Asia (Coleoptera: Carabidae: Harpalini), Acta Entomologica Musei Nationalis Pragae 49 (2), pp. 599-606 : 604-606

Trichotichnus (Pseudotrichotichnus) tenuitibialis sp. nov.

( Figs. 4 , 7 )

Trichotichnus miyakei: ITO (1991) : 159 (misidentification).

Type material. HOLOTYPE: J, ‘ Tanah Rata , singled in and around the town, Cameron Highlands, Pahang, Malaysia, 21.–30.iii.1995, O.Merkl leg.’ ( HNHM) . PARATYPES: 1♀, ‘ Cameron Hi , Tanah Rata, Malaysia, 7.iv.1974, Y.Kiyoyama leg. ’; 1 ♀, ‘ Maxwell’s Hill , Malaysia, 5.III.1974, Y. Kiyoyama leg. ’; 1 J 1 ♀, ‘ Tanah Rata , Malaysia, 29.v.1975, Y. Kiyoyama leg.’ ( NIKJ) ; 1 J 4 ♀♀, ‘ 2 km S Tanah Rata on Tapah Road, montane rainforest, at light, Cameron Highlands , Pahang, Malaysia, 29.iii.1995, O. Merkl & I. Szikossy leg. ’; 5 ♀♀, ‘ Tanah Rata , edge of degraded rainforest, at light, Cameron Highlands, Pahang, Malaysia, 21.iii.–2.iv.1995, O. Merkl leg. ’; 1 ♀, the same locality, flight intercept trap ( HNHM) .

Description. Body similar in shape to T. miyakei , pitchy black though a little lighter than in T. miyakei , iridescent on elytra; buccal parts, antennae and tarsi light brown, labrum, tibiae and femora reddish brown to light reddish brown, mandibles blackish brown.

Head more or less large, 0.69–0.71 times as wide as pronotum, very sparsely and microscopically punctate, moderately raised; labrum subquadrate, with apex almost straight or shallowly emarginate; clypeus weakly protruding at apical angles, sometimes slightly swollen behind anterior margin; clypeal suture deep, slightly sinuate in middle; frontal impressions also deepened throughout, straight, oblique; eyes not prominent; temples abruptly declined, one-third the eye length; buccal fissure widely separated from genuine ventral margin of eyes; antennae short, not reaching pronotal base, submoniliform, segment 3 as long as segment 4 and twice as long as segment 2; palpi slender, segment 3 of labial palpus 1.1 times as long as segment 2; suture of mentum not distinct only near lateral ends of submentum, median tooth narrow and pointed at apex, epilobes narrow and parallel-sided; microsculpture invisible under 80× magnification.

Pronotum gently convex, transversely subquadrate, widest at anterior third, 1.5 times as wide as long, at base 1.25 times as wide as on anterior margin, sides moderately arcuate in anterior half and straight in posterior half; surface mostly impunctate, punctures in basal foveae more sparse and finer than in T. miyakei ; anterior margin slightly emarginate, without border in middle; basal margin bordered only at sides or with broken border throughout; anterior angles weakly produced, clearly arcuate; basal angles angulate, slightly obtuse; lateral furrows wholly impressed in a line; basal foveae shallow or only flattened, very obscurely grooved at inner sides; front transverse impression very shallow, hind one more vague; median line distinct to more or less vague, not reaching both anterior and basal margin; microsculpture obscure, consisting of transverse meshes and lines on disc and of isodiametric meshes near basal punctures.

Elytra oblong, suboval, 1.25 times as wide as pronotum and 1.50–1.53 times as long as wide, uniformly convex; sides gently rounded behind humeri, subarcuate near middle and rounded in apical third; apices widely rounded, tips narrowly separated from each other; base almost straight, rounded at humeral angles; striae wide, deep and clearly crenulate, scutellar striole long; intervals almost flat or weakly elevated on disc, fairly convex apically and basally, interval 3 with discal pore near apical two-fifths; marginal series widely spaced, consisting of (8–9) + (9–11) umbilicate pores; microsculpture sparsely visible as transverse thin lines. Hind wings well developed.

Ventral surface almost smooth; metepisterna convergent behind, 1.6 times as long as wide; apical margin of abdominal sternite 6 truncate or very slightly emarginate in male and narrowly rounded in female, with four setae in both sexes.

Legs slender; fore tibiae weakly dilated apicad, not sulcate in apical fifth, with three spines along external margin near apex; hind tarsi short, 0.78 times as long as the width of head in male and 0.64–0.66 times as long in female, segment 1 0.79 times as long as segments 2 and 3 taken together, segment 2 1.25 times as long as segment 3 and twice as long as segment 4, all claws with two setae on both inner and outer ventral margin.

Aedeagus ( Fig. 7 ) large, stout, dorsal surface straight in middle in lateral aspect; apical orifice not wide, opening oblique, placed laterally, inner sac without sclerite; apical lobe wide, subtriangular.

Length: 7.8–10.0 mm; width: 3.7–4.3 mm.

Differential diagnosis. This new species is allied to T. (P.) miyakei , but in addition to the characters mentioned in the description, the body is smaller and the aedeagus is not arcuate dorsally but straight in middle.

Etymology. The species name is composed from the Latin tenuis (= slim, slender) and tibialis, referring to the slender tibiae of the species.

Distribution. Cameron Highlands (Peninsular Malaysia, Pahang state).

Remark. I treated the Malaysian specimens as T. miyakei (ITO 1991) , but a more detailed examination including the study of the aedeagus revealed that they belong to a separate species.

Figures

Figs. 1–5. 1–2 – Trichotichnus (Pseudtrichotichnus) jelineki sp. nov., holotype (1 – habitus; 2 – male genitalia); 3 – T. (P.) vietnamensis sp. nov.; 4 – T. (P.) tenuitibialis sp. nov.; 5 – T. (P.) niger Louwerens, 1951. Scale bar: 1 mm. Abbreviations: l – lateral aspect, d – dorsal aspect.

Figs. 6–9. Male genitalia. 6 – Trichotichnus (Pseudotrichotichnus) vietnamensis sp. nov.; 7 – T. (P.) tenuitibialis sp. nov.; 8 – T. (P.) niger Louwerens, 1951; 9 – T. (P.) miyakei Habu, 1980. Scale bar: 1 mm. Abbreviations: l – lateral aspect, d – dorsal aspect.