Atheta (Dimetrota) ovata Lee & Ahn, 2022

Lee, Seung-Gyu & Ahn, Kee-Jeong, 2022, Korean species of the Atheta Thomson subgenus Dimetrota Mulsant & Rey (Coleoptera: Staphylinidae: Aleocharinae) with a description of new species, Zootaxa 5138 (4), pp. 401-416 : 406-411

Atheta (Dimetrota) ovata Lee & Ahn , sp. nov.

( Figs. 1B , 3A–F , 4A–H , 5A–G , 6A–D )

Description. Length 2.5–3.2 mm. Body ( Fig. 1B ) surface glossy, densely pubescent with microsculpture. Body dark brown to black; antennae, elytra and legs paler than other parts, brownish. Head. Slightly transverse ( Fig. 4A ), approximately 1.1–1.2 times as wide as long, widest across eyes, slightly narrower than pronotum; eyes large and prominent, about 1.5–1.6 times as long as temples; gular sutures moderately separated, more or less diverged basally; cervical carina complete. Antennae ( Fig. 4B ) long and slender; antennomeres 1–3 elongate, 1 longest, 2 about as long as 3, 4–10 quadrate to subquadrate, 11 about as long as 1, about as long as preceding two combined. Mouthparts. Labrum ( Fig. 3A ) with 10–11 macrosetae on each side of midline; epipharynx ( Fig. 3B ) with α-sensillum long and setaceous, about 3.0 times as long as ε-sensillum; β- and γ-sensilla short. Mandibles ( Figs. 3C–D ) asymmetrical, subtriangular, decurved and pointed apically, about 1.5–1.6 times as long as basal width; very few small denticles present in molar region; right one ( Fig. 3C ) with small internal tooth, internal margin slightly serrulate; prostheca developed, composed of three portions, second portion slightly longer. Galea and lacinia of maxilla ( Fig. 3E ) long and slender; 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 2.5–2.7 times as long as wide, 4 digitiform, filamentous sensilla not reaching to basal half. Prementum ( Fig. 3F ) with two medial setae very narrowly separated; two basal pores contiguous, less than 1.0 times width of basal pore; several medial pseudopores, lateral pseudopores, 1 setal pore and 2 real pores present on each side of midline; labial palpomere 1 largest, about 1.5–1.6 times as long as wide, γ-setula contiguous with b-seta, 2 shortest, about 1.6–1.8 times as long as wide, 3 more or less dilated apically and slightly shorter than 1, about 2.5–3.0 times as long as wide. Mentum ( Fig. 3F ) trapezoidal, anterior margin slightly emarginate; v-seta relatively long, close to u-seta. Thorax. Pronotum ( Fig. 4C ) approximately 1.3–1.4 times as wide as long, widest in apical third to half. Prosternum as in Fig. 4D . Metanotal scutum ( Fig. 4E ) with 1 long seta and about 3–4 short setae on each side of midline. Mesoventral process ( Fig. 4F ) distinctly pointed at apex, longer than isthmus and metaventral process combined. Scutellum as in Fig. 4G . Elytra slightly longer and wider than pronotum; elytron ( Fig. 4H ) approximately 1.6 times as long as wide; hind wings fully developed, flabellum ( Fig. 4E ) composed of about 6–7 long setose lobes. Legs. Length ratio of tarsomeres 22:26:30:76 (protarsus); 30:35:38:35:68 (mesotarsus); 45:44:43:46:96 (metatarsus). Abdomen. Surface glossy and densely pubescent, with transverse and reticulate microsculpture ( Fig. 5C ); macrochaetal arrangement of tergites II–VI 02-13 (or 23)-23-23-23; male sternites III–VI with many small pores, VII with several small pores in anterior region; male tergite VIII ( Fig. 5A ) with 4 macrosetae on each side of midline, posterior margin ( Fig. 5B ) with broad process, slightly emarginate in median region and slightly angled in postero-lateral margins; male sternite VIII ( Fig. 5D ) with 10 macrosetae on each side of midline, posterior margin with inconspicuous marginal setae; posterior margin of female tergite VIII ( Fig. 5E ) truncate in median region; female sternite VIII ( Fig. 5F ) with 8 macrosetae, posterior margin ( Fig. 5G ) broadly rounded, with conspicuous and long marginal setae, minute setae present in median region. Aedeagus. Median lobe ( Figs. 6A–B ) narrowly ovate, apical process subtriangular and convergent at apex, apex slightly swollen and globular in ventral aspect. Apical lobe of paramerites ( Fig. 6C ) subparallel-sided, with 4 setae; b-seta longest, distinctly longer than other setae short and subequal in length, c- and d-setae close together. Spermatheca. Bursa elongate, with slender umbilicus; duct recurved, deflected at apex ( Fig. 6D ).

Type material. Holotype, ♂, labeled as follows: ‘ KOREA: Gangwon Prov., Pyeongchang-gun, Jinbu-myeon, Dongsan-ri , Mt. Odaesan , Sangwonsa , 22 VI–16 VIII 2001, S.-J. Park, C.-W. Shin, ex FIT’ . Paratypes, 9 exx., same data as holotype.

Material examined. SOUTH KOREA: Chungbuk Prov.: 3 exx., Buyeo-gun, Oesan-myeon, Gaedeok-ri, Mt. Wolmyeongsan, 1 vi 2000, US Hwang, HJ Kim, sifting; 1 ex., Danyang-gun, Mt. Sobaeksan, Cheongdong, 7–9 v 1999, US Hwang, HJ Kim, sifting. Chungnam Prov.: 1 ex., Gongju-si, Banpo-myeon, Sangsin-ri, Mt. Gyeryongsan, 21 v 2000, MS Kim, near stream. Gangwon Prov.: 1 ex., Hongcheon-gun, Naechon-myeon, Mt. Baekamsan, Garyeong fall, 25 v–20 vi 2002, KJ Ahn, SJ Park, JS Park, FIT; 2 exx., Hongcheon-gun, Nae-myeon, Mt. Gyebangsan, Unduryeong, N37° 42.49.9′ E128° 26.40.3′, 1100 m, 11 v 2007, TK Kim, YH Kim, fungus on log; 5 exx., Injegun, Mt. Jeombongsan, Gombaeryeong, 23–30 viii 1999, US Hwang, bait trap; 1 ex., Jeongseon-gun, Gohan-eup, Mt. Hambaeksan, 13 vii 1999, US Hwang, mushroom; 2 exx., Mt. Seoraksan, 23 viii 1996, T. Pierre, mushroom; 21 exx., Pyeongchang-gun, Cheondong-ri, Mt. Sambangsan, 13 vii–15 viii 2001, KJ Ahn, SJ Park, CW Shin, FIT in Pinus forest; 67 exx., Pyeongchang-gun, Jinbu-myeon, Dongsan-ri, Mt. Odaesan, Sangwonsa, 30 iv–4 vi 2001, KJ Ahn, SJ Park, MS Kim, MJ Jeon, FIT; 161 exx., same data as former except for ‘ 4 vi–22 vi 2001 ’; 9 exx., same data as former except for ‘ 18 viii 2000, MH Kim, entirely rotten mushroom ( Boletaceae )’; 5 exx., same data as former except for ‘ 22 viii 2000, KJ Ahn, JH Ahn’; 152 exx., same data as former except for ‘ 22 vi–16 viii 2001, SJ Park, CW Shin, FIT’; 15 exx., same data as former except for ‘ 16 viii–15 ix 2001 ’; 5 exx., same data as former except for ‘ 15 ix–14 xi 2001, KJ Ahn, CW Shin, FIT’; 9 exx., same data as former except for ‘ 21 iv–18 v 2002, SJ Park, CW Shin, FIT’; 17 exx., same data as former except for ‘ 18 v–23 vi 2002, SJ Park, JS Park, FIT’; 2 exx., same data as former except for ‘ 23 vi 2002, SJ Park, JS Park, mushroom’; 2 exx., same data as former except for ‘ 13 vii 2004, SM Choi, mushroom’; 6 exx., same data as former except for ‘ 18 vi 2004, SJ Park, FIT’; 27 exx., same data as former except for ‘ 18 vi–22 vii 2004, SJ Park, KM Yang, DH Lee, FIT’; 2 exx., same data as former except for ‘37°47′8.3″ E128°33′54.0″ 880 m, 10 ix 2009, TK Kim, YH Kim, leaf litter’; 17 exx., same data as former except for ‘ N37°47′3.4″ E128°33′44.6″ 930 m, 12 VI 2012, YH Kim, SG Lee, YG Ban, JC Lim, mushroom’; 2 exx., same data as former except for ‘Bukdaesa, 23 viii 2000, MH Kim, mushroom’; 2 exx., same data as former except for ‘Namdae jijangam, 12 ix 2007, HW Kim, YH Kim, mushroom’; 7 exx., Pyeongchang-gun, Jinbu-myeon, Mt. Odaesan, Woljeongsa, 22 viii–20 x 2000, KJ Ahn, FIT; 4 exx., Pyeongchang-gun, Mt. Odaesan, Jeokmyeolbogung, 7–9 vii 1998, KL You, HJ Lim, FIT; 1 ex., Pyeongchang-gun, Bangrim-myeon, Ungyo 2-ri, Mt. Baekdeoksan, 12 vii–16 viii 2001, KJ Ahn, SJ Park, CW Shin, FIT; 1 ex., Taebaek-si, Mt. Taebaeksan, Baekdansa, 16 vii 1999, US Hwang, HJ Kim, sifting; 1 ex., Yangyang-gun, Seo-myeon, Osaek-ri, Hangyeryeong, 16 viii 2000, MH Lim, mushroom; 3 exx., Yangyang-gun, Seo-myeon, Osaek-ri, Mt. Seoraksan, Osaekyaksu, 31 vii–15 ix 2002, SJ Park, CW Shin, JS Park, FIT; 3 exx., same data as former except for ‘Osaekyaksu, 20 vii 2004, SJ Park, KM Yang, KJ Ahn, mushroom’; 2 exx., Yeongwol-gun, Suju-myeon, Mt. Baekdeoksan, Gwaneumsa, 13 vii–15 viii 2001, KJ Ahn, SJ Park, CW Shin, FIT. 2 exx., Yeongwol-gun, Yeongwol-eup, Mt. Taehwasan, 14 viii 2001, MH Kim, mushroom ( Boletaceae ). Jeonbuk Prov.: 3 exx., Jeongeup-si, Mt. Naejangsan, Naejangsa, Geumseon valley, 15–24 vi 2000, US Hwang, HJ Kim, FIT.

Distribution. Korea (South).

Remarks. This species is very similar to Atheta (Dimetrota) machonryongica , but can be distinguished by the characters provided in the key and the different shape and structure of aedeagus and spermatheca. Most specimens were collected by FIT and from mushroom in forest.

Etymology. Named from Latin ovata meaning “ovate”, which refers to the shape of median lobe of aedeagus.

Figures

FIGURE 1. Habitus.A: Atheta (Dimetrota) machonryongica (3.0 mm); B: A. (D.) ovata sp. nov. (3.0 mm); C: A. (D.) yamamotoi (3.2 mm).

FIGURE 3. Atheta (Dimetrota) ovata sp. nov. A: labrum (dorsal aspect); B: epipharynx (ventral aspect); C: right mandible (dorsal aspect); D: left mandible (ventral aspect); E: left maxilla (ventral aspect); F: labium (ventral aspect).

FIGURE 4. Atheta (Dimetrota) ovata 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 5. Atheta (Dimetrota) ovata sp. nov. A: male abdominal tergite VIII (dorsal aspect); B: posterior margin of male abdominal tergite VIII (dorsal aspect); C: microsculpture of male abdominal tergite VIII (dorsal aspect); D: male abdominal sternite VIII (ventral aspect); E: female abdominal tergite VIII (dorsal aspect); F: female abdominal sternite VIII (ventral aspect); G: posterior margin of female abdominal sternite VIII (ventral aspect).

FIGURE 6. Atheta (Dimetrota) ovata sp. nov. A: median lobe of aedeagus (lateral aspect); B: median lobe of aedeagus (ventral aspect); C: paramere (lateral aspect); D: spermatheca. Scales = 0.1 mm.