Trilophidius gemmatus, Balkenohl, Michael, 2017

Balkenohl, Michael, 2017, Trilophidiusgemmatus sp. n., a new species from Bhutan, with an updated identification key to the Asian species (Coleoptera, Carabidae, Scaritinae), Alpine Entomology 1, pp. 51-56 : 51-53

Trilophidius gemmatus sp. n. Figs 1-2, 3-4, 5

Types.

Holotype: male, dry glued on a paper card pinned, with embedded genitalia on a separate card on the same pin, with printed white label "BHUTAN Thrumshingla NP - Mongar City 20.6.2010 coll. W. MARGGI, THUN" (NMBE).

Paratypes: 7 females, "Bhutan, 20.-27.6.2010 Thrumshingla Mongar city leg. Li Jingke / coll. H.Hebauer (CHR, CBB).

Remarks.

In the holotype, the apical spine of the left protibia is missing. In four of the seven paratypes the following joints are missing: one with no left protibia, one with no right middle leg, antennae in one specimen on the right side without joint three and onwards, and in one all tarsus joints are missing at the left middle leg.

Differential diagnosis.

A brown Trilophidius species with subelongate elytra having the maximum width behind middle, six setigerous punctures on the third elytral interval, and an incomplete fold-like carina in the channel at the apex of the elytra.

Distinguished from the related species T. impunctatus Putzeys, 1868, by the darker colour, the more robust appearance, the more convex habitus (pronotum and elytron), the internal structure of the male genitalia, and the pattern and shape of setae on the female coxostyli. From the second similar species, T. endroedii Balkenohl, 2001, it differs by the straight labrum, the minute humeral tooth and the male genitalia (all figures of the species mentioned are in Balkenohl 2001).

Description.

Measurements: Length 2.30-2.55 mm (x̅ = 2.42 mm*), width 0.71-0.81 mm (x̅ = 0.76 mm*), ratio length/width of pronotum 0.96-1.06 (x̅ = 1.01*), ratio length/width of elytra 1.66-1.82 (x̅ = 1.73*); (*n = 8).

Colour: Yellowish-brown. Front legs, margins of mandibles, reflexed margin of elytron, pronotum darker. Wings of clypeus yellowish transparent.

Head (Fig. 2): A third smaller than pronotum. Clypeus and wings finely reflexed margined; clypeus straight anteriorly, finely meshed and with minute punctures; wings projecting, rounded off, with fine transverse rugae, fused with clypeus, divided from supraantennal plates by distinct obtuse-angled notches; supraantennal plates not margined, convex, prolonged posteriorly as blunt supraorbital carina, interrupted at mid-eye level; triangular-like tubercle on vertex elongated posteriorly into a short sharp keel. Clypeus and frons divided from supraantennal plates by deep and broad longitudinal furrows. Furrows diverging posteriorly. Frons slightly convex, smooth and with few punctures. Neck constriction distinct at posterior-eye level, composed of small to medium sized irregu larly arranged band of punctures, interrupted at middle. Eyes large, convex; ommatidia distinct, convex; genae and tempora small. Labrum slightly excised, with indistinct reticulation, five-setose. Mandibles distinctly acute at apex, each with three molares basally.

Apical segment of maxillary palpomere conspicuously securiform, with four setae ventrally; terminal segment of labial palpomere bottle-like, with eight setae, penultimate segment bisetose, ligula with two long apical setae separated, paraglossae slightly broadened at apex. Mentum and submentum divided by deep furrow, with two pairs of setae each, median tooth triangular, small, moderately acute at apex, lobes moderately elongate, much longer than tooth, rounded anteriorly, with longitudinal reticulation. Gula with isodiametric reticulation. Antennae short, just reaching posterior setigerous puncture of pronotum, segment five to ten moniliform.

Pronotum: Outline subglobose, as long as wide, maximum width at middle. Disc convex. Anterior margin nearly straight. Reflexed lateral border distinct from anterior angles to posterior setigerous puncture. Proepisternum distinctly tumid laterally and well visible in dorsal view, most distinct in posterior third. Anterior angles distinct, obtuse-angular, bent downwards. Anterior transverse line visible at anterior angles. Median line distinct, sharp, deeper and broader towards base, not reaching anterior margin, not reaching channel of basal constriction. Surface with some fine irregular transverse wrinkles at median line towards base, with indistinct flat basal impression at each side. Basal ring-like flange, convex, three times as broad as channel of deep basal constriction.

Elytra: Convex in lateral and apical view. Anterior half flattened for a short distance (lateral view). Subelongate, sides slightly rounded anterior middle and diverging, evenly rounded apically. Maximum width slightly behind middle. Base slightly convex truncated. Marginal channel narrowed at middle of elytron, series of umbilical setigerous tubercles interrupted at middle for a short distance often 1-2 tubercles are missing, fold-like carina at apex incomplete; reflexed margin slightly undulate. Humeral tooth indistinct, situated in extended projection of seventh interval.

With two basal tubercles with setigerous punctures adjoining lateral margin at humerus, a distinct tubercle in the extended projection of the second stria. Scutellar stria visible as fine line. First stria deep up to tip of apex, stria two and three fairly deep, punctate-striate, other striae developed as rows of punctures, becoming fine apically; stria five broadly impressed at base, striae two to four shortened at base. Intervals slightly convex, eighths forming obtuse overhanging carina in apical two- fifths, third with series of six setigerous punctures situated at third stria in anterior half and towards the middle of the interval posteriorly.

Hind wings: Fully developed.

Ventral surface: Proepisternum with few transverse wrinkles, fine submarginal furrow visible at anterior angle up to anterior setigerous puncture, furrow between prosternum and proepisternum invisible in anterior third. First and second abdominal sternites with isodiametric meshes; terminal abdominal sternite with irregular reticulation, completely meshed in the male and in apical half in the female (160 times).

Legs: Protibia: Surface smooth; lateral upper spine curved ventrally. Movable spur smaller than spine, nearly straight, apically curved. Preapical lateral denticle robust, sharp, second one smaller. Profemur dorsolaterally with distinct coriaceous notches. Hind legs: Tarsomere one nearly as long as two and three combined.

Male genitalia (Figs 3, 4): Median lobe moderately arcuate, slightly convex in lateral view, with wrinkles and minute pili basally. Spatula at apex spoon like, with nodules. Endophallus without spines. Parameres somewhat distorted, both of them bisetose, petioles of moderate length.

Female genitalia (Fig. 5): Coxostylus one and two fused. Distinctly broadened basally, conspicuously curved and sharp at apex, with 4 dorsal and 5 ventral nematiform setae in the basal half and one big bottle like ensiform seta. The ensiform seta is hyaline apically.

Sexual dimorphism: Terminal abdominal sternites completely meshed with irregular reticulation in the male, and in apical half in the female (160 times).

Variation: In the eight specimens investigated the number and the arrangement of punctures of the neck constriction varies. In addition, the basal impression on the disc of the pronotum is more or less well developed. It is nearly invisible in two specimens to slightly but well visible in others. The reticulation on the clypeus is more or less distinctly developed (160 times).

Etymology.

The name refers to the nodules on the apical part of the aedeagus, which are looking like buds of a flower (in latin gemma; gemmatus = adjective in nominative singular).

Distribution.

The species was found in the Thrumshingla National Park, Bhutan. This National Park has an altitude of around 2500 m.

Ecology.

Unkown.