Hydrosmecta koreana Lee & Ahn 2024, sp. nov.
Creators: name: Lee, Seung-Gyu
name: Ahn, Kee-Jeong
Publisher: name: Zenodo
Year: 2024
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Coleoptera
Staphylinidae
Hydrosmecta
Hydrosmecta koreana

description: Hydrosmecta koreana Lee & Ahn, sp. nov.
(Figs. 1B, 3A–F, 4A–H, 5A–B, 6A–H)
Description. Length about 2.0– 2.3 mm. Body surface fairly glossy and densely pubescent, with fine microsculpture. Body dark brown; antennae, elytra and legs slightly paler. Head. Quadrate (Fig. 4A), about as wide as long, widest across eyes, about as wide as pronotum; eye large and distinctly prominent, about 1.4–1.5 times as long as temple; gular sutures moderately separated, more or less diverged basally; infraorbital carina absent; cervical carina absent. Antennomeres (Fig. 4B) distinctly elongate, 1 longest, 2 slightly longer than 3, 4 shortest, 11 about as long as 1, slightly shorter than preceding two combined. Mouthparts. Labrum (Fig. 3A) distinctly transverse, emarginate in anterior margin, with ε-sensillum and 6 macrosetae on each side of midline; epipharynx with several sensilla, including 2 lateral sensory rows on each side of midline; α-sensillum setaceous, less than 2.0 times as long as ε-sensillum; β- and γ-sensilla very short, pointed at apex. Mandibles (Fig. 3C–D) asymmetrical, elongate, decurved and pointed apically, approximately 1.8 times as long as basal width, internal margin slightly serrulate; right one (Fig. 3C) with pointed internal tooth; prostheca developed, composited three portions. Galea and lacinia of maxilla (Fig. 3E) slightly long and slender; lacinia composited seven spines in distal comb region, two isolated spines present; last spine of distal comb region and isolated spines close together; maxillary palpus elongate and pubescent; palpomere 1 smallest, 2 about 2.6–2.8 times as long as wide, 3 slightly longer than 2, about 2.2–2.4 times as long as wide, 4 digitiform, filamentous sensilla reaching to basal half. Labium (Fig. 3F) with ligula elongate and parallel-sided, divided into 2 lobes in apical half; prementum with 2 medial setae moderately separated; 2 basal pores narrowly separated, about 1.0–2.0 times width of basal pore; a few median pseudopores present, several lateral pseudopores, 1 setal pore and 2 real pores present on each side of midline; labial palpus elongate, with many setulae; palpomere 1 largest, about 1.7–1.8 times as long as wide, with γ-setula close to b-seta, 2 shortest, about 1.2–1.3 times as long as wide, 3 parallel-sided and slightly shorter than 1, about 3.5–4.0 times as long as wide. Mentum (Fig. 3F) trapezoidal, anterior margin slightly emarginate; v-seta very short. Thorax. Pronotum (Fig. 4C) transverse, 1.2 times as wide as long, widest in apical third, pubescence directed anteriorly in median region; hypomeron fully visible in lateral view. Scutellum as in Fig. 4G. Metanotal scutum (Fig. 4E) with 1 long seta and about 4–6 short setae on each side of midline. Mesoventral process (Fig. 4F) pointed at apex, shorter than isthmus and longer than metaventral process; length ratio of mesoventral process, isthmus and metaventral process 2:4:1. Elytra slightly longer and wider than pronotum; elytron (Fig. 4H) approximately 1.7 times as long as wide, pubescence directed posteriorly and postero-laterally; postero-lateral margin straight; hind wings fully developed, flabellum (Fig. 4E) composed of about 6 long setose lobes. Legs slender and long, with pubescence and macrosetae; middle and hind tibia with different length of 2 spurs at apex; tarsal formula 4-5-5, length ratio of tarsomeres 19:20:20:44 (front tarsus); 23:24:26:25:42 (middle tarsus); 36:33:31:29:46 (hind tarsus); 1 empodial seta present, shorter than claw. Abdomen. Surface glossy, with imbricate microsculpture (Fig. 5A–B); macrochaetal arrangement of tergites II–VI 01-02-12-12-12; male tergite VIII (Fig. 6A) with 4 macrosetae on each side of midline, posterior margin subtruncate; male sternite VIII (Fig. 6B) with 8 macrosetae on each side of midline, posterior margin subtruncate, with long marginal setae; posterior margin of female tergite VIII (Fig. 6C) truncate; female sternite VIII (Fig. 6D) with 6 macrosetae on each side of midline, posterior margin convex, very slightly prolonged, with long marginal setae, minute setae present in median region.
Aedeagus. Median lobe (Fig. 6E–F) ovate, apical process constricted in basal region and pointed apically in ventral view; apical process more or less foot shape, sharply bent ventrad in lateral view. Apical lobe of paramere (Fig. 6G) elongate and dilated apically, with four setae; b-seta longest, the other setae short, subequal in length. Spermatheca. S-shaped; bursa elongate, with long and large umbilicus; duct recurved (Fig. 6H).
Type material. Holotype, labeled as follows: ‘ Gangwon Prov., Jeongseon-gun, Jeongseon-eup, Joyang-river, N37°23'1.5" E128°38'41.8" 306 m, 27 V 2009, YH Kim, JH Song, near stream’. Paratypes, 17 exx., same data as holotype.
Distribution. Korea (South).
Remarks. This species is very similar to H. longula (Heer) in external form but can be distinguished by the body more flattened dorso-ventrally, antenna paler, antennomere 2 slightly longer than 3, and the form of aedeagus and the shape of spermatheca (see fig. 8 in Yosii & Sawada 1976). All specimens were collected near a stream by the Joyang river.
description: Published as part of Lee, Seung-Gyu & Ahn, Kee-Jeong, 2024, Korean species of Hydrosmecta Thomson (Coleoptera: Staphylinidae: Aleocharinae) with descriptions of two new species, pp. 265-274 in Zootaxa 5399 (3) on page 269, DOI: 10.11646/zootaxa.5399.3.5, http://zenodo.org/record/10516844