Euconnus wumengshanus Yin & Zhou 2025, sp. nov.
Creators: name: Yin, Zi-Wei
name: Zhou, De-Yao
Publisher: name: Zenodo
Year: 2025
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Coleoptera
Staphylinidae
Euconnus
Euconnus wumengshanus

description: Euconnus (s. str.) wumengshanus Yin & Zhou, sp. nov.
Chinese common name: 乌AE山ṀẆẅm
(Fig. 1)
Type material (1 ex.). HOLOTYPE: CHINA: ♂: ‘China: Yunnan, Zhaotong City, Wumengshan Natural Reserve, Sanjiangkou, Laziping, 28.207336°N, 103.914108°E, 1980 m, 15.vii.2022, Wei leg., 云南DZdz乌AE山三江口ḆŦ 坪M国Dzẍ ’ (SNUC).
Other material examined (1 ex.). 1 ♀: ‘ China: Yunnan, Zhaotong City, Wumengshan Natural Reserve, Xiaocaoba, Miaoshan, 27.846716°N, 104.292419°E, 1830 m, 20.vii.2022, Wei leg., 云南DZdz乌AE山海小¤坝庙 山M国Dzẍ ’ (SNUC).
Diagnosis. Male. Body length approximately 1.4 mm. Terminal four antennomeres greatly enlarged and forming distinct club, occupying approximately 6.2/10 of antennal length. Aedeagus with compressor plate broad and plate-like in ventral view, obliquely connected to median lobe in lateral view; apical projection of median lobe broad and protruding in ventral view, curved dorsally in lateral view; median lobe with pair of membranous, lateral projections apically rounded, and transversely rhomboidal plate on ventral wall; broad and elongate parameres narrowing from bases toward apices, each with two long setae at apex and two similar long setae at approximately apical 1/3. Female. External morphology similar to male, with antennomeres of clubs slightly shorter; spermatheca in lateral view transversely oval.
Description. Male. Body (Fig. 1A) length 1.41 mm; body uniformly reddish-brown, mouthparts and tarsi paler in color. Posterior margin of vertex, sides of head, and sides and disc of pronotum with scattered thick bristles, with long setae on body surface. Dorsum of body finely punctate.
Head roundly rhomboidal, broadest at eyes, length 0.32 mm, width 0.30 mm; vertex and frons confluent, convex; supraantennal tubercles barely prominent; eyes large, strongly convex and coarsely faceted. Punctures on vertex and frons fine; setae long, dense, suberect to erect, additionally tempora and vertex with long bristles directed posteriorly. Antenna moderately short, length 0.63 mm, club 0.39 mm; antennomeres 1 and 2 elongate, 3–7 compact, each short and distinctly transverse, 8–10 greatly enlarged, conical, 11 roundly conical, distinctly longer than 10, with sharp constriction at point of basal 2/5.
Pronotum in dorsal view subtrapezoidal, broadest at base and strongly narrowing anteriorly, length 0.38 mm, width 0.43 mm; lateral antebasal pits small but distinct, asetose, transverse antebasal groove shallow. Punctures on pronotal disc fine; setae moderately fine and obscured by dense, long and thick bristles especially on sides.
Elytra suboval and slightly flattened, broadest approximately at middle, length 0.82 mm, width 0.66 mm, length/ width 1.24; basal impressions shallow but distinct, humeral calli elongate; apices of elytra separately rounded. Punctures on elytral disc fine and shallow; setae long, sparse and strongly erect. Metathoracic wings fully developed, functional.
Legs long and slender; unmodified.
Aedeagus (Fig. 1D–E) moderately stout, dorso-ventrally almost symmetric, length 0.22 mm, in ventral view median lobe with abruptly delimited and long, broad apical projection greatly curved dorsally; compressor plate broad and plate-like in dorso-ventral view, subquadrate with narrowed apical margin, obliquely connected to median lobe in lateral view; lateral projections broad and membranous, curved dorsally, with round apices; ventral wall of median lobe with large, transversely rhomboidal plate, its apical margin with two admesal acute projection; parameres broad and elongate, narrowing from bases toward apices, each with two long setae at apex, two similar long setae at apical 2/5 and several short and thin setae at middle.
Female. Similar to male in habitus and external morphological features. Antennal clubs (0.34 mm) slightly shorter than male. Spermatheca (Fig. 1F) in lateral view transversely oval. Measurements (as for male): body length 1.40 mm, length/width of head 0.34/ 0.32 mm, pronotum 0.41/ 0.43 mm, elytra 0.81/ 0.67 mm, length of antenna 0.61 mm, longest diameter of spermatheca 0.09 mm.
Comparative notes. This is a typical member of the former subgenus Napochus Thomson, which has recently been treated as a junior synonym of the nominotypical subgenus (Jałoszyński 2021a). Napochus represents a fairly diverse group within Euconnus, and has been the subject of recent taxonomic efforts for the Australian (Jałoszyński 2015), European (Orousset 2021), and North American (Stephan et al. 2021) faunas. In China, only a few Euconnus species have been properly assigned to subgenera (Li, L.-Z. et al. 2019; Yin & Zhou 2024). Nevertheless, no species is known to possess an aedeagus that bears even a slight resemblance to that of E. wumengshanus sp. nov. Prior to this study, only one Euconnus species had been documented from Yunnan (Mount Tangli) (Li, Q.-Q. & Yin 2021), which is characterized by a modified male head and a stout, transverse aedeagus.
Distribution. Southwest China: Yunnan.
Etymology. The species’ name is a toponym derived from its type locality, Wumenshan National Nature Reserve.
Remarks. The association of the female specimen with the male holotype was based on the similarity in morphological features and proportions of body segments. However, the collection site of the female specimen is situated approximately 50 km southeast of Laziping, where the male was collected. Given this geographical separation, the possibility that the female represents a separate species cannot be excluded. Thus, this female has been omitted from the type series.
description: Published as part of Yin, Zi-Wei & Zhou, De-Yao, 2025, A report of the Scydmaeninae species (Coleoptera: Staphylinidae) taken from Wumenshan National Nature Reserve, Yunnan, China, pp. 531-540 in Zootaxa 5569 (3) on pages 532-533, DOI: 10.11646/zootaxa.5569.3.8, http://zenodo.org/record/14734857