Tmesiphorus shihongliangi, Yin, 2022

Yin, Zi-Wei, 2022, A new species of Tmesiphorus LeConte from northern Myanmar (Coleoptera: Staphylinidae: Pselaphinae), Zootaxa 5178 (6), pp. 577-582 : 578-581

Tmesiphorus shihongliangi sp. nov.

( Figs 1 , 2 )

Type material (13 exx.). Holotype: MYANMAR: ♂ , ‘ Myanmar, Kachin State, Putao Dist. , 2 km SE Ziradum, N27.5634, E97.1.64, 2016.xii.13, 1051 m, Shi H.L., in log’ ( SNUC) . Paratypes: MYANMAR: 3 ♂♂, 9 ♀♀, same data as for holotype ( SNUC, IZCAS) .

Diagnosis. Body length 2.1–2.2 mm; dorsal vestiture coarsely punctate and with short setae. Head sub-hexagonal, with small vertexal and frontal foveae; ocular canthi well developed. Pronotum broadest at anterior 1/3. Elytra distinctly ridged, discal stria forming broad impression with smooth area at base. Tergites 1 and 2 (IV and VI) each with one middle and one pair of lateral longitudinal carinae extending through tergal length. Male: Antennomere 9 broadly and deeply impressed on ventral surface, 10 asymmetrical. Protrochanter spinose at base. Sternite 1 and 2 (IV and V) shallowly impressed at middle. Aedeagus elongate; median lobe divided into two parts at apex; endophallus elongate; parameres each with three apical setae.

Description. Male. Body ( Fig. 1A ) length 2.14–2.20 mm; color reddish-brown, tarsi and mouthparts lighter. Dorsal vestiture coarsely punctate and covered with short setae.

Head ( Fig. 1B ) sub-hexagonal, truncate at base, wider than long, length 0.44–0.46 mm, width across eyes 0.48– 0.51 mm; vertex convex, with small vertexal foveae (dorsal tentorial pits), with thin, incomplete median carina; antennal tubercles moderately raised; frons greatly impressed medially, confluent with clypeus at middle; clypeus sharply declined, smooth, anterior margin rounded and carinate; lacking ocular-mandibular carina. Venter with two small gular foveae (posterior tentorial pits) in shared transverse opening, lacking median carina. Maxillary palpus ( Fig. 1C ) with palpomere 1 small, 2 pedunculate basally and enlarged apically, 3 lengthily subtriangular, 2 and 3 each with long, pencil-like, and apically setose protuberance on lateral margin, 4 greatly roundly and expanded laterally. Compound eyes greatly prominent, each composed of approximately 75 ommatidia; ocular canthus well developed. Antenna elongate, length 1.12–1.15 mm, distinctly clubbed ( Fig. 1D ) formed by greatly enlarged apical three antennomeres; antennomere 1 elongate, subcylindrical, 2–8 successively shorter, 8 shortest, 9 greatly enlarged, 10 much wider than 9, ventral surface broadly impressed, 11 smaller than 10, symmetrical at base.

Pronotum ( Fig. 1B ) slightly wider than long, length 0.44–0.46 mm, width 0.48–0.49 mm, widest at approximately apical 1/3; sides roundly expanded at widest point and evenly convergent posteriorly; disc moderately convex, lacking carina or sulcus; with small asetose median and setose lateral antebasal foveae; lacking basolateral foveae. Prosternum with anterior part slightly longer than coxal part at middle, with small, setose lateral procoxal foveae; lacking hypomeral ridge; margin of coxal cavity thinly carinate.

Elytra much wider than long, length 0.50–0.52 mm, width 0.81–0.85 mm; each elytron ( Fig. 1E ) with two large, setose basal foveae; disc distinctly carinate, stria forming broad, deep impression with smooth basal region, extending posteriorly from outer basal fovea to approximately half of elytral length; humeral region also distinctly raised, lacking subhumeral fovea or marginal stria; posterolateral margin with broad notch. Metathoracic wings fully developed.

Mesoventrite ( Fig. 2A ) almost impunctate, with pair of admesal carinae, with setose mediobasal sulcus and large, setose lateral mesoventral foveae; inter-coxal process short. Metaventrite ( Fig. 2A ) confluent with mesoventrite, coarsely punctate, with punctures much sparser laterally, broadly impressed posteromedially; with large, setose lateral mesocoxal foveae; posterior margin roundly and deeply emarginate at middle.

Legs elongate; protrochanter ( Fig. 2B ) with sharp, short spine at ventral margin, protibia distinctly curved and slightly expanded at middle; middle and hind legs lacking spine or tubercle.

Abdomen enlarged, coarsely punctate dorso-ventrally, widest at lateral margins of tergite 1 (IV), length 0.79– 0.82 mm, width 0.82–0.88 mm. Tergite 1 (IV) in dorsal view as long as 2 (V) ( Fig. 2C ), with deep, setose basal sulcus, 2 with thin basal sulcus, tergites 1 and 2 each with one median and two lateral longitudinal carinae extending through tergal lengths, 1–4 (IV–VII) each with one pair of basolateral foveae, 1–3 each with one pair of complete and 4 with triangular paratergites, 5 (VIII) with posterior margin broadly rounded, with one pair of small basolateral foveae, posterior margin roundly emarginate at middle. Sternite 2 (IV) ( Fig. 2D ) longest, with broad, setose basal sulcus interrupted at middle and one pair of basolateral foveae at lateral ends of sulcus, 3 (V) ( Fig. 2D ) slightly shorter than 2 at middle, 4 (VI) and 5 (VII) each short, combined shorter than 3 at middle, tergites 2 and 3 shallowly impressed at middle, 3–5 each with thin, asetose basal sulcus and one pair of basolateral foveae, 3 and 5 each with short setose fringe at basolateral margin, 6 (VIII) transverse, broadly emarginate at posterior margin, 7 (IX) ( Fig. 2E ) composed of one moderately sclerotized median and two membranous lateral plates.

Aedeagus ( Fig. 2F–H ) 0.42 mm long, asymmetrical; median lobe with large basal capsule and oval foramen, ventral stalk broad dorso-ventrally, curved ventrally in lateral view, apical part greatly concave at middle and divided into two parts; endophallus composed of single elongate sclerite; parameres short ( Fig. 2I ), each with three thin apical setae.

Female. Similar to male in external morphology; antenna slightly shorter, club less enlarged and lacking modifications; each compound eye composed of approximately 60 ommatidia; elytra relatively shorter and more constricted at bases; metathoracic wings also well-developed; protrochanter lacking ventral spine; sternite 2 (IV) and 3 (V) flat at middle. Measurements (as for male): body length 2.15–2.17 mm; length/width of head 0.44–0.46/ 0.47– 0.48 mm, pronotum 0.43–0.45/ 0.47–0.48 mm, elytra 0.49/ 0.79–0.81 mm; abdomen 0.80–0.84/0.0.86– 0.87 mm; length of antenna 1.06–1.07 mm.

Comparative notes. Two Tmesiphorus species described more than a century ago are known to occur in Myanmar: T. paulinae (Motschulsky) , and T. raffrayi Schaufuss ( Motschulsky 1851; Raffray 1883; Schaufuss, C. 1888; Blattný 1925). Tmesiphorus shihongliangi sp. nov. can be readily separated from them by the smaller body size (2.1–2.2 mm vs. 2.6 mm for T. paulinae and 2.66 mm for T. raffrayi ), and presence of three longitudinal carinae on tergites 1 (IV) and 2 (V). Both T. paulinae and T. raffrayi possess only one pair of lateral carinae on tergite 1, and lack any carina on tergite 2. The new species is morphologically similar to T. championi Jeannel from northern India by sharing the pattern of abdominal carinae. Tmesiphorus championi has a slightly larger body size (2.4 mm), and Jeannel’s (1960) original figures of the male antennal clubs and the aedeagus provided enough details to clearly separate this species from T. shihongliangi sp. nov.

Distribution. North Myanmar: Kachin State.

Bionomics. All individuals were collected under bark of large fallen logs in a broad-leaved rain forest.

Etymology. The new species is named after Hong-Liang Shi, who collected all the material and kindly offered them to me for study.

Figures

FIGURE 1. Tmesiphorus shihongliangi sp. nov., male. A. Dorsal habitus. B. Head dorsum and pronotum. C. Right maxillary palpus, ventral. D. Left antennal club, ventral. E Right elytron. Scale bars: 0.5 mm in A; 0.2 mm in B, D, E; 0.1 mm in C.

FIGURE 2. Tmesiphorus shihongliangi sp. nov., male. A. Meso- and metaventrite. B. Protrochanter. C. Tergites 1 (IV) and 2 (V). D. Sternites 2 (IV) and 3 (V). E. Sternite 7 (IX). F–H Aedeagus, dorsal (F), lateral (G), and ventral (H). I. Left paramere. Scale bars: 0.2 mm in A, C–H; 0.1 mm in B; 0.05 mm in I.