Triomicrus wumengmontis, Zhang & Yin, 2025

Triomicrus wumengmontis sp. nov.

Chinese common name: 乌®山鞭须ü甲

urn:lsid:zoobank.org:act:75EE1DDE-941D-489B-8EDD-555C30A94C7F Fig. 8 View Fig

Diagnosis

Male

Body length approximately 1.8–1.9 mm. Head and pronotum coarsely punctate. Eyes much shorter than tempora. Antennomere 11 simple, lacking modifications. Pronotum distinctly transverse. Elytra with short humeral striae extending for short distance. Protibia protuberant at apex; mesotibia with spine at apex. Posterior margin of sternite VII with hook-like expansion on left side. Aedeagus with left paramere (orientation according to figure) larger than right one, endophallus armature composed of three to four short, blunt sclerotized spines at middle of posterior half of capsule.

Female

Unknown.

Etymology

The specific epithet is derived from the Wumengshan Natural Reserve, the type locality for this species. The name is a noun in the genitive case.

Type material

Holotype CHINA • ♂; Yunnan, Zhaotong City, Wumengshan Natural Reserve , Haiziping , Dalingou ; 27.8799 ° N, 104.720011° E; 1180 m a.s.l.; 23 Jul. 2022; Wei leg.; Ǖ南昭ª乌®山AEŦū大ḢÁ魏ǡ豪*; SNUC. GoogleMaps

Paratypes CHINA • 1 ♂; same data as for holotype; SNUC GoogleMaps .

Description

Male BODY ( Fig. 8A View Fig ). Length 1.78–1.86 mm; colour reddish-brown, tarsi and mouthparts paler. Head and pronotum coarsely punctate, elytra and abdomen finely punctate; vestiture covered with moderately long setae.

HEAD ( Fig. 8B View Fig ). Roundly rectangle, subtruncate at base, approximate as long as wide, length 0.47– 0.49 mm, width 0.43–0.44 mm; vertex weakly convex, with broadly separated, setose foveae (dorsal tentorial pits); antennal tubercles barely raised; frons with distinct setose fovea, forming short rostrum; clypeus fused with frons at middle, evenly descending, with coarse surface, anterior margin arcuate and markedly carinate; ocular-mandibular carinae complete. Venter with two small, well-separated gular foveae (posterior tentorial pits), median longitudinal ridge broad and greatly convex. Maxillary palpus elongate; palpomere 1 minute; 2 extremely slender and long, pedunculate basally and broadened at basal ⅓ and at apex; 3 roundly trapezoidal, with short stem at base; 4 fusiform, with distinct stem at base, broadest at basal 2 /5, with long palpal cone. Compound eye relatively small, reniform in lateral view, each composed of approximately 25 ommatidia. Antenna moderately elongate, length 0.95–0.98 mm, lacking modifications, club formed by apical two antennomeres; antennomere 1 large, subcylindrical, 2 slightly narrower and shorter than 1, 3–8 each submoniliform, gradually shorter, 9 distinctly larger than 8, transverse, 10 much larger than 9, 11 ( Fig. 8C View Fig ) largest, much longer than 8 and 9 combined (27:16), subconical, obliquely narrowed at apex.

PRONOTUM ( Fig. 8B View Fig ). Much wider than long, length 0.43–0.45 mm, width 0.54 mm, widest at middle; sides rounded, narrowing from widest point anteriorly and posteriorly, both anterior and posterior margin almost straight; disc weakly convex, lacking carina or sulcus; with moderately distinct, setose median and lateral antebasal foveae; basal portion roughened. Prosternum with basisternal (precoxal) portion approximately as long as procoxal rests; with large, widely separated and setose lateral procoxal foveae; hypomera fully demarcated from pronotum by complete hypomeral grooves, hypomeral carinae close to coxal cavities.

ELYTRA. Roundly trapezoidal, wider than long, length 0.71–0.73 mm, width 0.82–0.84 mm, truncate at bases; each elytron with two asetose basal foveae; sutural striae complete, discal striae extending from outer fovea to approximately apical ¾ of elytral length; humeri roundly prominent, with small subhumeral foveae and thin marginal striae extending for less than half of elytral length; posterior margin slightly notched laterally. Metathoracic wings present but reduced for some extent.

MESOVENTRITE. Laterally fused with metaventrite, with median mesoventral foveae in single setose oval impression, large lateral mesoventral foveae unforked, extended internally and meeting each other at middle; intercoxal process short and narrow, with round apex. Metaventrite moderately prominent admesally; with large lateral metaventral and lateral mesocoxal foveae; posterior margin broadly and roundly emarginate at middle.

LEGS. Elongate; protibia ( Fig. 8D View Fig ) with small tubercle at apex; mesotibia ( Fig. 8E View Fig ) with acute apical spine.

ABDOMEN. Narrower than elytra, widest at base of tergite 1 (IV), length 0.43–0.45 mm, width 0.71– 0.73 mm, tergites 1–4 with well-developed accompanying paratergites. Tergite 1 (IV) dorsally much longer than 2 (V) and 3 (VII) combined, lacking basal impression, with one pair of small mediobasal and one pair of larger basolateral foveae; discal carinae moderately long, subparallel posteriorly, extending posteriorly for slightly over half tergal length; 2–4 (VIII) successively shorter and narrower, each with one pair of small basolateral foveae; 5 (VIII) roundly trapezoidal, transverse, posterior margin slightly arcuate. Sternite 2 (IV) longest, with two pairs of basolateral foveae, 3–5 (V–VII) each short at middle, compact, 3 with one pair of small basolateral foveae, 4 (VI) and 5 lacking foveae, posterior margin of sternite 5 (VII) ( Fig. 8F View Fig ) with acute, hook-like expansion on left side (orientation according to figure), 6 (VIII) narrow, ring-like, 7 (IX) ( Fig. 8G View Fig ) composed of paired membranous lamellae, slightly sclerotized at apices.

AEDEAGUS ( Fig. 8H View Fig ) 0.30 mm long, dorso-ventrally asymmetric; median lobe with large, round and membranous basal capsule; left paramere wider and longer than right one, moderately broadened at apex, right paramere slightly curved, rounded at apex; endophallus armature composed of three to four small, blunt sclerotized spines at middle of posterior half of capsule.

Female

Unknown.

Remarks

The form of the modification of male sternite 5 (VII) and the aedeagus suggest a close relationship between this species and two congeners: T. punctifrons Löbl, Kurbatov & Nomura, 1998 distributed in south and southwest China (Chongqing, Shaanxi, Sichuan, Guangxi) ( Löbl et al. 1998) and T. tibialis Shen & Yin, 2015 occurring in eastern China (Zhejiang) ( Shen & Yin 2015). However, T. wumengmontis sp. nov. can be readily separated from both species by the lack of modifications on antennomere 11. While the simple antennomere 11 is shared with T. onerosus Löbl, Kurbatov & Nomura, 1998 found in Taiwan, eastern China, the male of T. onerosus has significantly more strongly thickened pro- and mesotibiae ( Löbl et al. 1998), along with a head and pronotum that are finely punctate, contrasting with the coarsely punctate features of T. wumengmontis . Previously, only one species of the genus, T. nabanhensis Shen & Yin, 2016 , has been known from Yunnan ( Shen & Yin 2016). The male of that species has modified antennomeres 11, widened protibiae, and completely different structures of sternite 5 (VII) and aedeagus.

Distribution

Southwest China: Yunnan.