Syntectodes politus Yin, 2023

Yin (殷子为), Zi-Wei, 2023, A New Species of Syntectodes Reitter (Coleoptera: Staphylinidae: Pselaphinae) from the Himalaya, The Coleopterists Bulletin 77 (1), pp. 32-34 : 32-34

Syntectodes politus Yin , new species

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( Fig. 1 )

Type Material. HOLOTYPE: NEPAL: ♀, “NEPAL, S Dhaulagiri Mts., Phedi to Phalegaon , 1100- 1800 m, 09.V.2012, env. 28°28′ N, 83°21′ E, leg. Schmidt / collection NATURKUNDE-MUSEUM ERFURT / Coll. SENM, in MHNG, loan 23.x.2015 ” ( SENM) .

Diagnosis. Body length approximately 2.6–2.7 mm; integument smooth, shiny; head with punctiform frontal fovea, ocular canthus weakly developed, indistinct, setose tuft on posterolateral margin reduced in size; maxillary palpomere 3 with moderately protruding lateral margin (vs. margin greatly angularly protruding in all other known species), palpomere 4 lacking flattened crenulate setae, smoothly swollen laterally; median and lateral antebasal foveae of pronotum large and distinct; discal stria of elytra broad, short and shallow.

Description. Body ( Fig. 1A ) length 2.65 mm; color reddish-brown, tarsi and mouthparts lighter. Body surface smooth, shiny, with very short, sparse setae.

Head ( Fig. 1B ) sub-hexagonal, truncate at base, slightly longer than wide, length 0.51 mm, width across eyes 0.48 mm; vertex flattened, slightly convex at posterior part, with distinct vertexal foveae (dorsal tentorial pits); antennal tubercles barely raised; frons broadly impressed medially, forming distinct rostrum, confluent with clypeus at middle; clypeus sharply descending, smooth, anterior margin rounded and prominent; lacking ocular-mandibular carina. Venter with two tiny gular foveae (posterior tentorial pits) in shared transverse slit, lacking median carina or sulcus. Maxillary palpus ( Fig. 1D ) with palpomere 1 small, 2 pedunculate basally and enlarged apically, 3 roundly subtriangular, apicolateral corner moderately protruding, 4 smoothly rounded and swollen laterally. Compound eyes ( Fig. 1C ) moderately prominent, each composed of approximately 50 small ommatidia; ocular canthus reduced to single carina, with a few thickened setae.Antenna elongate, length 1.21 mm, club formed by enlarged apical three antennomeres; antennomere 1 thick and 34 elongate, subcylindrical, 2–8 each moniliform, 8 shortest, 9 much larger than 8, 10 much wider and longer than 9, 11 slightly longer than 9 and 10 combined, truncate at base, slightly curved.

Pronotum ( Fig. 1B ) as long as wide, length and width 0.50 mm, widest at middle; sides roundly expanded at widest point and evenly convergent posteriorly, abruptly narrowed at apical one-third and smoothly narrowing anteriorly; disc greatly convex at middle, lacking carina or sulcus; with large asetose median and lateral antebasal foveae; with one pair of basolateral foveae. Prosternum with anterior part shorter than coxal part at middle, with small lateral procoxal foveae; hypomeron ( Fig. 1C ) lacking ridge; margin of coxal cavity slightly carinate.

Elytra much wider than long, length 0.55 mm, width 0.84 mm; each elytron with two large, setose basal foveae; discal stria forming short, broad and shallow impression; humeral region moderately raised, lacking subhumeral fovea or marginal stria; posterolateral margin with broad notch, posterior margin with row of dense setae. Metathoracic wings fully developed.

Mesoventrite almost impunctate, with moderately separated median and large, setose lateral mesoventral foveae; intercoxal process short, rounded at apex. Metaventrite confluent with mesoventrite, impunctate, slightly convex admesally; with large, setose lateral mesocoxal foveae; posterior margin roundly and broadly emarginate at middle.

Legs elongate; protibia widened to middle, slightly arcuate, mesal margin of protibia and ventral margin of profemur with stiff setae.

Abdomen elongate, widest at posterolateral margins of tergite 1 (IV), length 1.0 mm, width 0.88 mm. Tergite 1 (IV) with broad, setose basal impression, lacking basal foveae, posterior margin with row of thickened setae, 2 (V) longest and approximately 1.5 times as long as 1, with narrower basal impression, 3 (VI) approximately half length of 2, 4 (VII) shorter than 3, roundly narrowing posteriorly, 2–4 each with one pair of basolateral foveae, 1–3 each with one pair of complete and 4 with one pair of triangular paratergites, 5 (VIII) ( Fig. 1E ) transverse, with posterior margin broadly rounded and slightly emarginate at middle, with one pair of small basolateral foveae. Sternite 2 (IV) with broad, setose basal sulcus, 3 (V) more than twice as long as 2 at middle, and with setose basal sulcus, 1 and 2 each with one pair of basolateral sockets, 4 (VI) and 5 (VII) each short, combined shorter than half length of 3 at middle, lacking basal sulcus or basolateral fovea, 6 (VIII) ( Fig. 1F ) strongly transverse, 7 (IX) ( Fig. 1G ) weakly sclerotized, greatly transverse.

Male. Unknown. Comparative Notes. Although only a single female is available, this species can be easily distinguished by its smooth, glabrous integument. In contrast, all known congeners have a distinctly punctate body surface, and the lateral margins of the third maxillary palpomeres are much more strongly protruding than those of the new species.

Distribution. Nepal: Gandaki Province.

Biological and Collection Information. In Pselaphinae a shiny, glabrous integument is a common evolutionary trend found in inquilinous species belonging to various tribes (summarized in Parker and Owens 2018), which indicates myrmecophily/ termitophily. According to the collector, the beetle was found in an open, wet channel beside a crop field from either leaf litter or under stones, and many ants of different genera were also collected during the survey. Unfortunately, no specific note was made for the pselaphine (J. Schmidt, personal communication). Thus, future efforts are required to find the associated male (the two sexes likely share a glabrous appearance), and to determine the potential host ant of this species.

Etymology. The specific epithet polītus (- ta, - um) is a Latin participle meaning “polished, smoothed”, referring to the shiny appearance of this species.

Figures

Fig. 1. Syntectodes politus, new species, female. A) Dorsal habitus, B) Head and pronotum, dorsal, C) Head and prothorax, lateral, D) Right maxillary palpus, ventral, E) Tergite 5 (VIII), F) Sternite 6 (VIII), G) Sternite 7 (IX). Scale bars: 1.0 mm in A; 0.3 mm in B, C; 0.1 mm in D, G; 0.2 mm in E, F.