Euconnus (s. str.) magnoculus Zi-Wei Yin, Ting Feng & De-Yao Zhou, 2025

Yin, Zi-Wei, Feng, Ting & Zhou, De-Yao, 2025, First report of subfamily Scydmaeninae (Coleoptera, Staphylinidae) from Shanghai, with description of two new species, ZooKeys 1231, pp. 133-143 : 133-143

Euconnus (s. str.) magnoculus Zi-Wei Yin, Ting Feng & De-Yao Zhou sp. nov.

Figs 3 , 4

Type material

(1 ex.). Holotype: China: • ♂: ‘ China: Shanghai, Hongqiao Dist., Shanghai Zoo , 31.198056°N, 121.354964°E, alt. 10 m, 07. vi. 2023, Ting Feng leg., 上海动物园封婷采’ ( SNUC) .

Diagnosis.

Male. Body length approximately 1.5 mm. Eyes greatly prominent, approximately 1.4 × as long as tempora. Terminal four antennomeres greatly enlarged and forming distinct club, occupying approximately 5.5 / 10 of antennal length. Sides of elytra distinctly narrowing posteriorly from broadest point. Aedeagus with compressor plate elongate and subfusiform in ventral view; apical projection of median lobe rounded and greatly protruding in ventral view, curved dorsally in apical portion in lateral view; median lobe with pair of apically rounded lateral projections, and transversely rhomboidal plate on ventral wall; broad and elongate parameres narrowing from bases toward apices, each with two long setae at apex and three similar long setae along apical 2 / 5. Female. Unknown.

Description.

Male. Body (Fig. 3 A ) length 1.52 mm; body uniformly reddish-brown, mouthparts and tarsi paler in color. Setae long and suberect, tempora of head and sides of pronotum with dense, thick bristles. Dorsum of body finely and sparsely punctate.

Head roundly rhomboidal, as long as wide, broadest at eyes, length and width 0.31 mm; vertex and frons confluent, weakly convex; supraantennal tubercles barely prominent; eyes large, strongly convex and coarsely faceted. Punctures on vertex and frons fine; setae long and sparse, suberect, additionally tempora with long bristles directed posteriorly. Antenna moderately short, length 0.56 mm, club 0.31 mm; antennomeres 1 and 2 subcylindrical, elongate, 3–7 compact, gradually larger, 8–11 greatly enlarged, conical, 11 largest, distinctly shorter than 9 and 10 combined.

Pronotum in dorsal view subtrapezoidal, broadest at base and strongly narrowing anteriorly, length 0.35 mm, width 0.38 mm; lateral antebasal pits small but distinct, asetose, connected by transverse antebasal groove. Punctures on pronotal disc fine; setae long, obscured by dense, long and thick bristles especially on sides.

Elytra suboval and slightly flattened, broadest approximately at middle, length 0.89 mm, width 0.63 mm, length / width 1.39; basal impressions shallow but distinct, with four small, asetose basal pits, humeral calli elongate; apices of elytra separately rounded. Punctures on elytral disc fine and shallow; setae long, sparse and suberect. Metathoracic wings fully developed, functional.

Meso- and metaventrite fused. Sides of mesoventral intercoxal process posteriorly divergent, form pair of ridges, similar to condition in E. maklinii (Mannerheim) ( Jałoszyński 2021: fig. 8). Metaventral intercoxal process relatively narrow.

Legs long and slender; unmodified.

Aedeagus (Fig. 3 B – E ) moderately elongate, dorso-ventrally almost symmetric, length 0.31 mm, in ventral view median lobe with abruptly delimited and long, broad apical projection greatly curved dorsally, rounded at apex; compressor plate relatively narrow and subfusiform in dorso-ventral view, with narrowed anterior and posterior margins, connected in parallel to median lobe in lateral view; lateral projections broad and partially sclerotized, curved dorsally, with round apices; endophallus armature composed of pairs of complex, symmetric sclerotized plates and large, transversely rhomboidal plate, its apical margin with two admesal roundly acute projections; parameres broad and elongate, narrowing from bases toward apices, each with two long setae at apex, and three similar long setae along apical 2 / 5.

Female. Unknown.

Comparative notes.

Among the East Asian Euconnus fauna, several species exhibit a similar general shape of the aedeagus. These include E. efferus Franz from China (Taiwan) ( Franz 1985), E. deprecator Kurbatov from the Russian Far East ( Kurbatov 1993), and E. akane Hoshina from Japan ( Hoshina 2020). Despite the similarities, these species are distinctly differentiated by their endophallus armature, which comprises asymmetric sclerites. In contrast, the new species possesses an aedeagus that is almost symmetric both externally and internally. Additionally, similarly symmetric aedeagi are found in E. kelantanensis Franz from West Malaysia and E. parakelantanensis Franz from north-central Thailand; however, these species are considerably smaller, measuring only 1.20 mm and 1.10 mm in length, respectively ( Franz 1970, 1985).

Distribution.

East China: Shanghai (Hongqiao) (Fig. 4 A ).

Biology.

The specimen was collected from a leaf litter sample taken in a secondary mixed forest within Shanghai Zoo (Fig. 4 F ).

Etymology.

The name is a combination of the Latin adjective “ magnus (great, large) ” and noun “ oculus (eye) ”, referring to the large eyes of this species.

Figures

Figure 3. Euconnus (s. str.) magnoculus sp. nov., male A dorsal habitus B – E aedeagus, lateral (B, D) and ventral (C, E). Scale bars: 0.5 mm (A); 0.1 mm (B – E).

Figure 4. Distribution and collecting circumstances of Euconnus species in Shanghai A distribution of the three species B – D collecting circumstance of E. dulcis at Minhang (B), Sheshan (C), and Liudao (D), E. imparitus sp. nov. at Quanjing Village (E), and E. magnoculus sp. nov. at Shanghai Zoo (F).