Cercyon (Cercyon) undulipennis, Ryndevich & Jia & Fikáček, 2017

Ryndevich, Sergey K., Jia, Fenglong & Fikáček, Martin, 2017, A review of the Asian species of the Cercyon unipunctatus group (Coleoptera: Hydrophilidae: Sphaeridiinae), Acta Entomologica Musei Nationalis Pragae (Acta. Ent. Mus. Natl. Pragae) 57 (2), pp. 535-576 : 550-552

Cercyon (Cercyon) undulipennis sp. nov.

( Figs 6 , 13 )

Type locality. China, Sichuan, NNE slope of Gonggashan Mts., cca 4000 m, 29.53°N 102.01°E.

Type material. HOLOTYPE: ♂ ( NHMB): ‘W Sichuan, 9–11.VII.1994, 29º53’N 102º01’E, cca 4000 m, Gonggashan, mts. , NNE sl, lgt. D. Král & J. Farkač.’. PARATYPES: CHINA: SICHUAN: 144 spec. ( NHMB, NMPC, CSR): same data as the holotype; 12 spec. ( NHMB): Gonggashan-Hailuogou , 2900–3200 m, 29º35’N 102º00’E, 3–6.vii.1994, D. Král & J. Farkač leg.; 22 spec. ( NHMB): Mioxi-Hailuogou , 1200–1900 m, 29º37’N 102º07’E, 1–7.vii.1994, D. Král & J. Farkač leg.; 10 spec. ( NHMB): Gonggashan, Hailuogou , above Camp 3, 29°35’N 102°00’E, 3000 m, 6.vii.1996, J. Farkač, P. Kabátek & A. Smetana leg.; 261 spec. ( NHMB, NMPC, CSR): Gonggashan, Hailuogou , above Camp 2, 2600–2750 m, 29º35’N 102º00’E, 3–6.vii.1998, J. Farkač leg.; 84 spec. ( NHMB, NMPC, CSR): Gonggashan, Hailuogou , above Camp 3, 2800–3300 m, 29º35’N 102º00’E, 6–8.vii.1998, J. Farkač leg.; 5 spec. ( NHMB): Gonggashan, Hailougou , above Camp 3, 3200 m, 29°35’N 102°00’E, 7.vii.1996, J. Farkač, P. Kabátek & A. Smetana leg.; 12 spec. ( NHMB): Gonggashan, Hailougou , above Camp 3, 3050 m, 29°35’N 102°00’E, 6.vii.1996, J. Farkač, P. Kabátek & A.Smetana leg.; 8 spec. ( NHMB): Rte. 138 , 15 km W Kangding, 3250 m, 29º57‘N 101º54‘E, 19.vii.1998, D. Král leg.; 11 spec. ( NHMB): Moxi, Gonggashan Mts. , 3100 m, 28.vi.–2.vii.1994, Bolm leg.; 5 spec. ( NMPC):Gonggashan Mt., NW of Moxi, 2950 m, 29º41’N 101º58’E, 14–19.vi.1999, V. Siniaev &A.Plutenko leg.; 1 spec. ( CSR): NW of Jiuxiangzhen, 29º33’34’’N / 102º20’46’’E, 2460 m, 10.vii.2009, Belousov & Kabak leg.; 1 spec. ( ZISP):NW of Mianning, 2645 m, 28º38’45’’N 102 º03’50’’E, 5.vi.2012, Belousov, Davidian, Kabak, Korolev leg. ; 192 spec. ( NMPC, KMNH, SYSU, NHMW, BMNH): Emeishan Mt., Leidongping env., on human faeces in mixed forest, 2140 m, 29°32’23’’N 103°19’52’E’, 8–9.vi.2014, J. Hájek, J. Růžička & M. Tkoč lgt.; 1 spec. ( NMPC): Emeishan Mt., Leidongping env., near steap track to temples below, bamboo groove, in debris under rock abyss, 2140 m, 29°32’49’’N 103°20’22’E’, J. Hájek & J. Růžička lgt.; 3 spec. ( NMPC): Moxi env., Hailuogou valley, below Cableway station, mixed forest with Abies , Rhododendron , broadleaf bushes, flat forest near brook, baited pitfall trap (fish meat), 3000 m, 29°34’24’’N 101°59’40’’E, 18–21.vi.2014, J. Hájek & J. Růžička lgt.; 3 spec. ( NMPC): Emeishan Mt., Taiziping Temple , mixed forest with Abies and bamboo undergrowth, baited pitfall trap (fish meat), 2820 m, 29°31’50’’N 103°19’36’E’, 8.vi.2014, J. Hájek & J. Růžička lgt.; 44 spec. ( NMPC): Moxi env., Hailuogou valley, above Cableway station, mixed forest with Abies , Betula , Rhododendron and broadleaf trees, baited pitfall trap (fish meat), 3100 m, 29°34’28‘‘N 101°59‘24‘‘E, 18–21.vi.2014, J. Hájek, J. Růžička & M. Tkoč lgt.; 1 spec. ( NMPC): 34 km N of Baoxing, Qiaofeng, 2015 m, 30°40.6‘N 102°45‘E, 22.vi.2014, J. Hájek lgt.; 2 spec. ( NMPC): Moxi env.Hailogou valley, Caohaizi (lakes), above Camp 2, mixed forest with Abies , Pinus , Rhododendron , broadleaf bushes and bamboo, baited pitfall trap (fish meat), 2770 m, 29°35‘11‘‘N 102°01‘36‘‘E, 18–21.vi.2014, J. Hájek & J. Růžička lgt.; 1 spec. ( CAPG): Ya’an Prefecture, Tianquen County, E of Erlang Shan Pass, 2900 m, 29°52.36‘N 102°17.82‘‘E, 20.vi.1999, A Pütz leg.

Additional material examined. CHINA: YUNNAN: 3 ♀♀ ( CAS, CSR): Najiang Lisu Aut. Pref., Gaoligong Shan, side valley, 19 km NW Liuku 2590 m, 25°58’10’’N 98°42’27’’E, devastated primary forest, sifted litter, 9–10. vi.2007, W. Wrase leg.

Diagnosis. Head black; pronotum yellowish with large central black spot; elytron brownish- -yellow, maxillary palpi yellowish, last palpomere darker; head, pronotum and elytra with sparse short pale hairs; elytral intervals slightly convex in medial and apical parts; mesoventral plate narrowly elongate, ca. 7.9–11.0× as long as wide; metaventrite without femoral lines; fifth abdominal ventrite not emarginate apically; paramere rather wide basally, nearly straight on outer margin, narrowly rounded apically, apex with setae; median lobe widest at midlength, almost parallel-sided except for apical 1/8, pointed apically; sternite 9 narrowly rounded with 4 long subapical setae, base rounded.

Description. Form and color. Body elongate oval ( Fig. 6A ), length 2.4–3.0 mm, width 1.5–1.7 mm. Head black with very small brownish preocular spots. Pronotum brownish-yellow with large vaguely defined central dark spot leaving all pronotal margins widely pale. Scutellum brown to dark brown. Elytra and epipleura brownish-yellow. Antennae yellowish except for darker club. Maxillary palpomeres yellowish, last palpomere darker. Ventral surface dark brown to black, ventral plate and metaventral pentagon brown to dark brown, posterior margins of abdominal ventrites yellowish or brownish. Legs brownish-yellow to brownish.

Head. Dorsal surface with sparse short pale hairs. Clypeus with dense, moderately coarse punctures, interstices without microsculpture. Anterior margin of clypeus with narrow bead. Frontoclypeal suture undetectable. Frons without microsculpture on interstices. Eyes small, somewhat protruding, interocular distance 6.0× the width of one eye in dorsal view. Mentum glabrous, ca. 1.6× as wide as long, sparsely and finely punctate.Antennae with 9 antennomeres, scapus ca. 1.3× as long as antennomeres 2–5 combined, club compact. Maxillary palpomere 2 strongly swollen, palpomere 4 almost symmetrical, equal to palpomere 3 in length.

Thorax. Pronotum and elytra with sparse pale hairs. Pronotum ca. 2.0–2.1× as wide as long. Pronotal punctation similar to that on head. Lateral margins of pronotum with narrow bead overlapping anterior and posterior corners, anterior and central part of posterior margin without bead. Prosternum with strong longitudinal carina medially; antennal groove distinct, moderately large, angulate laterally. Mesoventral plate very narrowly elongate, 7.9–11.0× as long as wide, widest at midlength ( Fig. 6F ). Metaventrite with raised glabrous sparsely punctate median pentagonal area; femoral lines absent. Elytra with ten punctate striae, striae 1–9 impressed and reaching base, stria 10 very short; intervals slightly convex in medial and apical parts, ground punctures on intervals very fine; humeral bulge not distinct. Epipleuron flat, horizontal. Femora with sparse and shallow punctures ventrally, with distinct tibial groove. Tarsi with densely arranged whitish setae ventrally, first metatarsomere about as long as metatarsomeres 2–3 combined.

Abdomen. Abdomen with five ventrites, first ventrite distinctly longer than other ventrites, ca. 2× as long as second ventrite, with distinct median longitudinal carina, fifth ventrite arcuate, not emarginate apically.

Male genitalia ( Figs 6B–D ). Phallobase shorter than parameres, asymmetrical basally. Paramere rather wide basally, abruptly narrowing in apical third, straight on outer margin, narrowly rounded apically; apex membranous, apex and inner edge with setae subapically. Median lobe rather wide, nearly parallel-sided throughout except at apex, base with short ароdemes, apex pointed; gonopore large, situated subapically. Sternite 9 with narrowly rounded median projection bearing four long subapical setae, base rounded; median portion shorter than lateral struts.

Variation. All examined specimens from Sichuan are rather uniform in morphology and coloration. The females from western Yunnan are larger in body size (length 3.0 mm, width 1.7 mm) than Sichuan specimens, have wider mesoventral plate (8.0–8.5× as long as wide) and their elytra are darker in central part. Since no male was available from that locality which is moreover far from other known records, we are excluding these specimens from the type series.

Etymology. The species name reflects the convex elytral intervals; composed Latin adjective undulipennis (- is, - e) derived from Latin unduli- (undulate) and penne (wing, elytra).

Biology. The specimens were collected from cow and human excrements and from baited pitfall traps in forests at altitudes of 1200–4000 m a.s.l. They seem to be very common in some localities in Sichuan.

Distribution. The species seems to be common in the mountains of central Sichuan; its occurrence in Yunnan is here recorded on the basis of three females and needs to be confirmed by male specimens.

Figures

Fig. 6. Cercyon undulipennis sp. nov. A – dorsal and lateral habitus of paratype from China: Yunnan: Gaoligong Shan; B–D – male genitalia of the holotype (B – tegmen; C – median lobe; D – sternite 9). E–H – ventral morphology (E – meso- and metaventrite; F – detail of mesoventral plate; G – mentum; H – prosternum and antennal groove).

Fig. 13. Known distribution of the species of C. unipunctatus species group in Asia.