A taxonomic review of Korean Acrotona Thomson with a description of new species (Coleoptera, Staphylinidae, Aleocharinae) Author Lee, Seung-Gyu Division of Forest Biodiversity, Korea National Arboretum, Pocheon 11186, South Korea. jspdi @ naver. com Author Ahn, Kee-Jeong Department of Biology, Chungnam National University, Daejeon 34134, South Korea. kjahn @ cnu. ac. kr text Zootaxa 2018 2018-05-08 4418 3 247 263 journal article 22661 10.11646/zootaxa.4418.3.3 bace504a-09db-4a62-a010-f903f2d92d22 1175-5326 3769610 959FE164-2912-42F8-B44E-52DC26B85C5A Acrotona ( Acrotona ) koreana Lee & Ahn , sp. nov. ( Figs. 1B , 2 A–F, 3A–H, 4A–H) Description. Length about 2.0 mm. Body ( Fig. 1B ) surface fairly glossy and densely pubescent, with fine microsculpture. Body reddish yellow to reddish brown; head almost black; abdominal segments V–VII darker than other parts. Head . Transverse ( Fig. 3A ), approximately 1.2 times as wide as long, widest across eyes, distinctly narrower than pronotum; eyes very large, about 2.0 times as long as temples; gular sutures moderately separated, diverged basally; cervical carina complete. Antennae ( Fig. 3B ) long and slender; antennomeres 1–3 elongate, 2 slightly longer than 3, 4–10 subquadrate to transverse, 11 longest, about as long as preceding two combined. Mouthparts . Labrum ( Fig. 2A ) transverse, slightly emarginate in anterior margin, with ε-sensillum and about nine macrosetae on each side of midline; epipharynx ( Fig. 2B ) with several sensilla, including two lateral sensory rows on each side of midline; α-sensillum long and setaceous, more than 2.0 times as long as ε-sensillum, β- and γsensilla very short. Mandibles ( Figs. 2 C–D) about 1.7 times as long as basal width; right one ( Fig. 2C ) with small internal tooth; prostheca composed of three portions, second portion longer. Galea and lacinia of maxilla ( Fig. 2E ) long and slender; lacinia composed of seven spines in distal comb region, two isolated spines present; maxillary palpomere 2 about 2.6–2.8 times as long as wide, 3 about 2.3–2.5 times as long as wide, 4 digitiform, filamentous sensilla not reaching to basal half. Labium ( Fig. 2F ) with ligula long and slender, divided into two lobes in basal half; prementum with two medial setae narrowly separated; two basal pores close together, about 1.0 times width of basal pore; medial pseudopores absent; several lateral pseudopores, 1 setal pore and 2 real pores present on each side of midline; labial palpomere 1 about 1.3–1.5 times as long as wide, γ-setula contiguous with f-seta, 2 shortest, about 1.2–1.3 times as long as wide, 3 parallel-sided and about as long as 1, about 3.0–3.5 times as long as wide. Mentum ( Fig. 2F ) trapezoidal, anterior margin emarginate; v-seta very long, slightly closer to u-seta than w-seta. Thorax . Pronotum ( Fig. 3C ) approximately 1.4 times as wide as long, widest at basal third to half; pubescence directed posteriorly in midline. Metanotal scutum ( Fig. 3E ) with one long seta and about one to four short setae on each side of midline. Mesocoxal cavities narrowly separated; mesoventral process ( Fig. 3F ) slightly pointed at apex, distinctly longer than isthmus and metaventral process combined. Elytra longer and slightly wider than pronotum; elytron ( Fig. 3H ) approximately 1.4–1.5 times as long as wide, postero-lateral margin sinuate; pubescence directed posterior and postero-laterally; hind wings fully developed, flabellum ( Fig. 3E ) composed of about six long setose lobes. Legs . Slender and long, with pubescence and macrosetae; meso- and metatibiae with different length of two spurs at apex; length ratio of tarsomeres 19:24:22:52 (protarsus); 27:28:29:27:50 (mesotarsus); 34:36:35:33:60 (metatarsus); one empodial seta present, shorter than claw. Abdomen . Widest in segments III–IV; surface fairly glossy and densely pubescent, fine and transverse microsculpture; conspicuous macrosetae present in lateral regions; macrochaetal arrangement of tergites II–VI 01-02-12-13-13; tergite VII subquadrate; male tergite VIII ( Fig. 4A ) with four macrosetae on each side of midline, posterior margin truncate; male sternite VIII ( Fig. 4B ) with seven macrosetae on each side of midline, posterior margin slightly convex; posterior margin of female tergite VIII ( Fig. 4C ) similar to male’s; female sternite VIII ( Fig. 4D ) with six macrosetae on each side of midline, posterior margin broadly round, with long marginal setae and in median region. Aedeagus . Median lobe ( Figs. 4 E–F) narrowly ovate and widest in basal fourth, narrow apically and blunt at apex in ventral aspect; apical process elongate and almost straight in lateral aspect. Apical lobe of paramerites ( Fig. 4G ) elongate and parallel-sided, with four setae; a-seta slightly longer than other setae positioned apically; b- and d-setae subequal in length; c-seta slightly shorter. Spermatheca . Bursa round, without umbilicus; duct relatively slender, coiled and twisted at apex ( Fig. 4H ). FIGURE 3. Acrotona ( Acrotona ) koreana sp. nov. A, head (ventral aspect); B, antenna; C, pronotum (dorsal aspect); D, prosternum (ventral aspect); E, metanotum (dorsal aspect); F, meso- and metaventrites (ventral aspect); G, scutellum (dorsal aspect); H, elytron (dorsal aspect). FIGURE 4. Acrotona ( Acrotona ) koreana sp. nov. A, male abdominal tergite VIII (dorsal aspect); B, male abdominal sternite VIII (ventral aspect); C, female abdominal tergite VIII (dorsal aspect); D, female abdominal sternite VIII (ventral aspect); E, median lobe of aedeagus (lateral aspect); F, median lobe of aedeagus (ventral aspect); G, paramere (lateral aspect); H, spermatheca. Scales = 0.1 mm. Type material. Holotype , labeled as follows: ‘ KOREA : Chungnam Prov. , Daejeon-si , Seo-gu , Jangan-dong , Mt. Jangtaesan , N36°13'01.0" E127°20'34.6" 222 m , 29 V 2014 , SG Lee , JS Lee , leaf litter’ . Paratypes , 6 exx. (two on slide), same data as holotype. Distribution. Korea (South). Remarks. This species is similar to A. lutulenata (Sharp) , but can be distinguished by the characters provided in the key and different shape and structure of the aedeagus and spermatheca.