Euconnus dulcis Sharp 1886
Creators: name: Yin, Zi-Wei
name: Feng, Ting
name: Zhou, De-Yao
Publisher: name: Zenodo
Year: 2025
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Coleoptera
Staphylinidae
Euconnus
Euconnus dulcis

description: Euconnus (s. str.) dulcis Sharp, 1886
Figs 1, 4
Euconnus dulcis Sharp, 1886: 47; Hoshina 2019: 201. Type locality: Nagasaki.
Euconnus (s. str.) dulcis Sharp; Jałoszyński 2022: 3; Byeon et al. 2023: 321.
Euconnus chinensis Li, J. - K. & Wang, Z. - Y., 1993: 163 (nec. E. chinensis Franz, 1985: 114). Type locality: Ningguo. Syn. nov.
Euconnus cerastiventris Vit, 2006: 75 (replacement name for E. chinensis Li, J. - K. & Wang, Z. - Y.). Syn. nov.
Material examined
(5 exx.). • 1 ♂: ‘ China: Shanghai City, Minhang Dist., 31°01'N, 121°28'E, alt. 4 m, 6. iv. 2014, Xiao-Bin Song leg. ’; • 2 ♀♀: ‘ China: Shanghai City, Songjiang Dist., East Sheshan, 9. iv. 2021, Xiao-Bin Song leg. ’; • 3 ♀♀: ‘ China: Shanghai City, Jiading Dist., Liudao, 31°29'38"N, 121°14'3"E, alt. 3 m, 3. x. 2023, Yin & Zhou leg. ’. (all in SNUC).
Diagnosis.
Male. Body length 1.4–1.7 mm. Dorsum of body finely punctate. Thick bristles present on tempora and sides of pronotum, especially dense on tempora. Anterior margin of clypeus (Fig. 1 B) angularly prominent at middle. Antenna elongate, club loosely formed by apical four moderately enlarged antennomeres, occupying about half of antennal length. Pronotum bell-shaped, with two asetose basolateral pits connected by shallow transverse impression. Each elytron with two closely-placed basal pits. Abdomen greatly modified (Fig. 1 C), sternite 4 (VI) and 5 (VII) each with two posterolateral nodules directed posteromedially, area between nodules on sternite 4 filled with peg-like granules distributed roughly in two transverse rows. Aedeagus (Fig. 1 D, E) with apical projection much longer than parameres; endophallus armature composed of group of symmetric sclerites; parameres each greatly broadened, bearing two long setae near apex and three similar setae along lateral margin. Female (Fig. 1 A). External morphology similar to male. Abdomen unmodified. Spermatheca (Fig. 1 F) spherical; spermathecal duct broadened at base.
Description.
See Vit (2006) and Jałoszyński (2022). Measurement for Shanghai population: male body length 1.48 mm; length / width of head 0.35 mm / 0.34 mm, pronotum 0.38 mm / 0.37 mm, elytra 0.78 mm / 0.63 mm, length of antenna 0.81 mm, club 0.42 mm, length of aedeagus 0.27 mm; female body length 1.49–1.53 mm; length / width of head 0.37–0.39 mm / 0.34–0.38 mm, pronotum 0.41–0.43 mm / 0.39–0.41 mm, elytra 0.86–0.88 mm / 0.67–0.71 mm, length of antenna 0.77–0.80 mm, club 0.36–0.38 mm, maximum diameter of spermatheca 0.27 mm.
Distribution.
East China: Anhui, Shanghai (Minhang, Songjiang, Jiading) (Fig. 4 A); Japan: Honshu, Kyushu; South Korea: Jeju. New record for Shanghai.
Biology.
Adult specimens were obtained by sifting grass roots, and mixed bush and bamboo leaf litter (Fig. 4 B – D).
Remarks.
This species exhibits a wide distribution across East Asia and is readily distinguishable by an angulate clypeus in both sexes, a sexually dimorphic abdomen in the male, and a distinctive morphology of the aedeagus. The descriptions and illustrations presented by Vit (2006) and Jałoszyński (2022) offer compelling evidence supporting the proposed synonymy. The spermatheca (Fig. 1 F) of this species is illustrated for the first time.
description: Published as part of Yin, Zi-Wei, Feng, Ting & Zhou, De-Yao, 2025, First report of subfamily Scydmaeninae (Coleoptera, Staphylinidae) from Shanghai, with description of two new species, pp. 133-143 in ZooKeys 1231 on pages 133-143, DOI: 10.3897/zookeys.1231.142538