Tyrodes tibialis, Zhang & Yin, 2023

Zhang, Yong-Qin & Yin, Zi-Wei, 2023, A new species of Tyrodes Raffray (Coleoptera: Staphylinidae: Pselaphinae) from China, Zootaxa 5293 (3), pp. 596-599 : 597-599

Tyrodes tibialis sp. nov.

( Fig. 1 )

Chinese common name: ẊṘṁLjaeẘffl

Type material (3 exx.). HOLOTYPE: CHINA: ♁: ‘China: Guangxi, Guilin City , Huaping N. R., 25°33′44.76″N, 109°56′17.08″E, 13560 m, 23.iv.2021, Yin, Zhang, Pan & Shen leg. [ ŨMAE ḢỄḾő]’ ( SNUC) . PARATYPES: CHINA: 1 ♁, same collection data as for holotype, except ‘ 21-22.iv.2021, FIT (flight intercept trap)’; 1 ♁, ‘China: Guangxi, Huanjiang, Jiuwan Mt, Qinshuitang , 25°11′59.36″N, 108°47′46.55″E, 450 m, 24.iv.2021, Tang, Peng, Cai, Song leg. [ŨMhvhƜNjứRffiḵae]’ ( SNUC) .

Diagnosis. Male. Body length approximately 1.8–2.1 mm. color reddish-brown, dorsal surface of body covered with relatively long pubescence. Head truncate at base, with punctiform vertexal and frontal fovea. Antenna relatively elongate, antennomere 1 (scape) angularly expanded at base of lateral margin, distinct club formed by apical three enlarged antennomeres. Pronotum with punctiform median and small lateral antebasal foveae connected by transverse sulcus. Discal striae of elytra shallow and short. Mesal margin of metatibia with small, short preapical projection. Sternite 3 (V) with lateral portions broadly concaved. Aedeagus dorso-ventrally asymmetric, relatively elongate, median lobe with lateral expansion at apical 1/3, endophallus armature with three elongate sclerites. Female. Unknown.

Description Male. Body ( Fig. 1A ) length 1.86–2.08 mm; color reddish-brown, tarsi and mouthparts lighter. Dorsal surface of body covered with dense, long pubescence.

Head ( Fig. 1B ) truncate at base, approximately as long as wide, length 0.40–0.43 mm, width across eyes 0.41–0.43 mm; vertex with small, asetose, and moderately separated foveae (dorsal tentorial pits); tempora short, rounded, densely setose; frons roughly punctate admesally, anteriorly forming distinct rostrum, with punctiform frontal fovea, antennal tubercles weakly convex, cavities broad; clypeus connecting with frons by distinct median ridge, with smooth surface, its anterior margin moderately carinate and moderately raised; ocular-mandibular carinae absent, ocular canthi moderately convex. Venter with smooth surface; tiny gular foveae (posterior tentorial pits) in shared transverse opening, lacking median carina or sulcus. Compound eyes prominent, each composed of 45 ommatidia. Maxillary palpus ( Fig. 1C ) with palpomere 1 small, 2 basally pedunculate and broadened apically, 3 pedunculate at base for short distance and then broadened toward apex, 4 largest, with short stem at base, suboval, with long palpal cone at apex. Antenna relatively elongate, length 1.29–1.37 mm, antennomere 1 (scape) with coarse surface, angularly expanded at base of lateral margin, 2–8 sub-moniliform, 9–11 each enlarged and forming distinct club, 11 much shorter than 9 and 10 combined (0.28 mm: 0.38 mm).

Pronotum ( Fig. 1B ) slightly broader than long, length 0.40–0.45 mm, width 0.41–0.45 mm, widest approximately at middle; lateral margins subparallel in basal half, convergent anteriorly from middle toward anterior margin, both anterior and posterior margins slightly arched; disc moderately convex, finely punctate and densely setose, with small, asetose median and lateral antebasal foveae connected by thin but distinct transverse sulcus, lacking carina or spine. Prosternum with anterior part slightly shorter than coxal part, with distinct, setose and widely separated procoxal foveae; hypomera fused with sternum, smooth; margin of coxal cavity thinly carinate.

Elytra with long pubescence, much wider than long, length 0.52–0.60 mm, width 0.80–0.91 mm; each elytron with two moderately large, asetose basal foveae; discal striae short and shallow, extending posteriorly from outer basal fovea to approximately 3.9/10 of elytral length; humeral denticle absent, humeri rounded, lacking subhumeral fovea or marginal stria; posterior margin with row of dense setae. Metathoracic wings fully developed.

Mesoventrite short, laterally fused with metaventrite; median mesoventral foveae moderately separated, originating from shared setose, transverse opening, large lateral mesoventral foveae broadly forked internally, with short, apically truncate mesoventral process. Metaventrite at middle with large, blunt projection before posterior margin, with large, setose lateral mesocoxal foveae and one median metaventral fovea, posterior metaventral process with small emargination at middle.

Legs moderately elongate, mesal margin of metatibia ( Fig. 1F ) with small, short preapical projection.

Abdomen widest at lateral margins of tergite 1 (IV), length 0.61–0.71 mm, width 0.74–0.87 mm. Tergite 1 (IV) longest, 1.5× as long as 2 (V), with broad, setose basal sulcus and two pairs of basolateral foveae, lacking discal carinae; tergites 2–4 (V–VII) each with one pair of basolateral foveae, 3 shorter than 2 and 4; tergite 5 (VIII) semicircular, transverse, posterior margin broadly and shallowly emarginate at middle. Sternite 2 (IV) at middle as long as 3–6 (V– VIII), approximately 3.5× as long as 3, with deep, setose basal impression and pair of basolateral sockets, lateral portions of sternite 3 broadly concaved, 4 short at middle, lacking foveae, 5 at middle longer than 4, with pair of small basolateral foveae, 6 transverse, roundly emarginate at middle, 7 (IX) ( Fig. 1G ) semi-sclerotized, subtriangular, apical margin with scattered setae.

Aedeagus ( Fig. 1H, I ) 0.38 mm long, dorso-ventrally asymmetric, moderately elongate; median lobe with large basal capsule and round diaphragm, narrowing from base toward apex, with large expansion at left side (orientation according to Fig. 1I ), apex with several small spines and one larger hook, parameres short, roundly triangular, endophallus armature with three elongate sclerites.

Female. Unknown.

Comparative notes. This species is distinct within the genus in having modified metatibiae, which bear a small preapical projection on the mesal margin. The presence of a lateral expansion of the aedeagal median lobe is shared by T. histrio (Schaufuss, L. W.) from Sri Lanka ( Jeannel 1957: fig. 29). These two species can be readily separated by the larger body size (2.08 mm vs. 1.5 mm), relatively much more elongate male antennal clubs, much narrower elytra and abdomen in relation to head and pronotum, and a different structure of the endophallus armature of T. tibialis . The new species clearly differs from the only other Chinese congener, T. jenisi Yin & Li from Yunnan ( Yin & Li 2013), by the more elongate antennal clubs, as well as by the form of the aedeagus.

Bionomics. Two individuals were found from sifted leaf litter samples in broad-leaved forests, while one was collected by a flight intercept trap.

Distribution. Southwestern China: Guangxi.

Etymology. The new specific epithet, tībiālis , is a Latin adjective, meaning, ‘tibial’, referring to the tibial modification of the new species.

Figures

FIGURE 1. Morphology of Tyrodes tibialis sp. nov., male. A. Dorsal habitus. B. Head dorsum and pronotum. C. Maxillary palpus. D. Scape. E. Antennal club. F. Apical portion of metatibia. G. Sternite 7 (IX). H, I. Aedeagus, lateral (H) and dorsal (I). Scale bars: 0.5 mm in A; 0.3 mm in B, D; 0.1 mm in C, E, F, G; 0.2 mm in H. I.