Peltocercyon maculipennis Mai, Jia, Ryndevich

Mai, Zuqi, Jia, Fenglong, Ryndevich, Sergey K., Angus, Robert, Minoshima, Yûsuke N., Fikáček, Martin & Růžička, Jan, 2025, Taxonomic Revision and Phylogeny of the Genus Peltocercyon d'Orchymont, 1925 (Coleoptera: Hydrophilidae: Megasternini), Zootaxa 5671 (1), pp. 1-74 : 40-44

Peltocercyon maculipennis Mai, Jia, Ryndevich , Angus & Fikáček sp. nov.

Figs 21A–H , 22A–E .

Type material examined. Holotype: male ( NHMUK), “ Taiwan , Natou / Chiayi Co. / SE of Alishan, 2300 m / 23º28’2’’N, 120º51’E / L. Dembicky, 6–8.xi.2008 / NHMUK 2008-85.” Paratypes: CHINA: Sichuan : 1 male ( SYSU), “ China, Mt. Emei / Sichuan Prov. / 17–VII–2003 / Hu & Tang leg.” ; 1 female ( SHNU), “ Mt. Emei / Sichuan Prov. / 17–VII–2003 / Li Zhenli leg.” ; Chongqing: 1 female ( NMP), “CHINA: Chongqing Jinyun Mt. (mount with a temple) / near Beipei (= Beibei ), 900 m, 29°50.5’N 106°23.5’E [based on interpretation by F.-L. Jia 2013] / Reitter lgt. // Tempelberg / 900 m / Ginyün b. Bĕbé / C. China, Rttr.” ; Guangxi: 6 spec. ( SYSU), “ China: Guangxi Prov. / Shangsi County / Mt. Shiwandashan / alt. 300–700 m / 24–IV–2011 / PENG, ZHAI & ZHU leg.” ; 43 spec. ( NMP), “CHINA: Guangxi / Shiwandashan National Forest Park 28.75 km SSW of Shangsi / 21°54.3’N 107°54.2’E; 300 m, 5–9.IV.2013, FikÁček,HÁjek &Růžička lgt.// baited pitfall traps [rotten cheese+fish] in secondary broad-leaf evergreen forest with sparse understory and rich in leaf litter” ; 3 spec. ( NMP), “CHINA: GUANGXI A. R., Shiwandashan National Forest Park, (baited pitfall trap in broadleaved forest), 5–9.IV.2013 / 21°54.3’N, 107°54.2’E, 300 m / M. FikÁček, J. HÁjek & J. Růžička lgt.” ; Guizhou: 5 spec. ( SYSU), “ Guizhou: Qianlingshan Park , flight intercept trap, 31.Ⅴ. –05.VI.2024, Xun Li, Baoxiang Zhan leg.” 4 spec. ( SYSU), “ Guizhou: Guiyang, Xiuwen County, Zhazuo Town , 26.7822°N, 106.7838°E, flight intercept trap, 29.Ⅴ. –04.VI.2024, Rixin Jiang leg.”; Taiwan : 7 spec. ( NMW), “TAIWAN, Tailung Hsien / Hsinkangshan above Chengkung 800m 26.IV.1995, A. Smetana [T167]” 1 spec. ( NMNS), “TAIWAN: Taichung Heping, Xiaosyueshan Giant Tree Trail , 2220m, 10.viii.- 15.x.2023, 24.257380 121.007818, flight intercept trap, BH Ho, Y Ho.” 3 spec. ( NMNS) 2 spec. ( TARI) 1 spec. ( BHHC), “TAIWAN: Pingtung Mt. Kavulungan trail, monkey excrements in the submontane broadleaf forest, 1300m, 10.ix.2022, 22.618838 120.701452, FikÁček, Ho, Peng.” 1 spec. ( NMNS), “TAIWAN: Hualien Kalabao, Xiulin Township , human dung, 15-17.vii.2019, 24.1667N, 121.4042E BH Ho” 3 spec. ( NMNS) , 3 spec. ( TARI) , 1 spec. ( BHHC), “TAIWAN: New Taipei Fushan Botanical Garden , 640m, 21.viii.-13.ix.2022, 24.7624N 121.5826E, flight intercept trap BH Ho, FS Hu, M. FikÁček” 6 spec. ( NMNS) , 6 spec. ( TARI) , 1 spec. ( BHHC), “TAIWAN: Taitung Daren, Dahanshan Logging Road 25 km (大OiƜūDz), pitfall traps with human dung, 1570m, 25.iii.- 6.iv.2024, 22.404795N 120.758452E, BH Ho, Y Ho” 3 spec. ( NMNS) , 2 spec. ( TARI) , 1 spec. ( BHHC), “TAIWAN: Taoyuan Fuxing, Sileng (四"), pitfall traps with human dung, 1160m, 4.iv.-4.v.2024, 24.649944N 121.424889E BH Ho, Y Ho ” 5 spec. ( NMNS) , 5 spec. ( TARI) , 1 spec. ( BHHC), “ TAIWAN: Nantou Lugu, Wutuku logging Rd. , dung-baited pitfall traps, 1550m, 16.iv.-24.vii.2022, 23.6777222N, 120.8088611E, BH Ho, Y Ho” 1 spec. ( NMNS), “TAIWAN: Chiayi Alishan Hwy., beginning of Lulinshan Trail, sifting in Cryptomeria forest , 2320m, 26.vi.2024, 23.4729539, 120.8460967, Faille & FikÁček” ; 378 spec. ( NMNS, NMP, BHHC, ADMU), Taiwan: Taitung Haiduan, Jingping logging road, flight intercept trap, 1520m, 29.iv.-15.vii.2024, 23.163342N, 121.144153E, BH Ho, M Liu ”. VIETNAM: 5 spec. ( NMP), “ N. Vietnam, 1985 / Tam Dao , 3–11.6. / 900–1400 m / J. Jelínek lgt.” . 1 male, 5 female ( SKRC), “VIETNAM, Tam Dao National Park , 12.05.- 15.05.2019. h= 1001 m, N 21°27’10.1’’ E 105°38’53.3’’, FIT#2, A. Derunkov leg.” . LAOS: 35 spec. ( NMP), “LAOS-NE, Houa Phan Prov., 20°13’09–19’’N 103°59’54’’– 104°00’03’’E, 1480–1510 m, PHOU PANE Mt., 2–22.VI.2011, Vit. KubÁň leg. // Primary mountain forest, flight intercept trap. / Laos 2011 Expedition / National Museum Prague, / Czech Republic.” 30 spec. ( NHMB), “LAOS, Phongsaly Prov., 21°41–2’N 102°06–8’E / 28.Ⅴ. –20.VI.2003, PHONGSALY env., / 1500 m, Vit. KubÁň leg.” 20 spec. ( NHMB), “LAOS, Phongsaly Prov., PHONGSALY env., / 6–17.Ⅴ.2004, 1500 m, / 21°41’N 102°06–8’E / Vit. KubÁň leg.” . INDIA: 34 spec. ( ZFMK), “NE INDIA, ARUNACHAL PR. / ETALIN vicinity. 700 m / 28°36’56’’N 95°53’21’’E / FIT (flight interception trap) / L. Dembický leg. , 12.–25.Ⅴ.2012.

DNA vouchers. MF1316: 1 spec. ( NMP), “ CHINA: Guangxi / Shiwandashan National Forest Park 28.75 km SSW of Shangsi / 21°54.3’N 107°54.2’E; 300 m, 5–9.IV.2013, FikÁček, HÁjek & Růžička lgt. // baited pitfall traps [rotten cheese+fish] in secondary broad-leaf evergreen forest with sparse understory and rich in leaf litter // DNA isolate: DNA extraction: MF1316, DNA extract stored at Department of Entomology , National Museum, Prague”; MF468 : 1 spec. ( NMP), “LAOS-NE, Houa Phan Prov., 20°13’09–19’’N 103°59’54’’ – 104°00’03’’E, 1480–1510 m, PHOU PANE Mt., 2–22.VI.2011, Vit. KubÁň leg. // Primary mountain forest, flight intercept trap. / Laos 2011 Expedition / National Museum Prague, / Czech Republic. // DNA isolate: DNA extraction: MF468, DNA extract stored at Department of Entomology , National Museum, Prague”. MZ102 : 1 male ( NMP), “ TAIWAN: Nantou Lugu, Wutuku logging Rd., dung-baited pitfall traps, 1550m, 16.iv.-24.vii.2022, 23.6777222N, 120.8088611E, BH Ho, Y Ho // DNA isolate: DNA extraction: MZ102, DNA extract stored at Department of Entomology , National Museum, Prague ””

Diagnosis. Length 3.1–3.7 mm. Head black. Pronotum and elytra yellowish to reddish brown; pronotum with an M-shaped large black patch on disc; each elytron with a large black patch lateromedially ( Fig. 21A, B, D ). Pronotum with uniform crescent-shape punctures. Elytra shiny, spaces between ground punctation smooth. Mentum with very sparse and fine punctures ( Fig. 22A ). Posterior tentorial pits without distinct depression ( Fig. 22A ). Prosternum tectiform medially; lateral portion with sparse and fine setae, without ridge; prosternal process finely notched posteriorly ( Fig. 22B ). Antennal groove broad ( Fig. 22B ). Mesoventral plate spindle-shaped ( Fig. 22C ). Arcuate ridge of metaventrite strongly bent backwards and distinct. Lateral areas of metaventrite without coarse punctures ( Fig. 22D ). First abdominal ventrite without longitudinal sculptures basally. ( Fig. 22E ). Male genitalia ( Fig. 21E–H ): paramere slightly widened subapically and then gradually narrowing towards apex, apex bluntly pointed and slightly curved inwards; inner face of paramere with a fringe of long setae subapically and few apical setae ( Fig. 21E, G ). Median lobe widest in the middle and gradually narrowing towards apex; apex bluntly pointed ( Fig. 21F ).

Description. Form and Colour ( Fig. 21A–D ). Total length 3.1–3.7 mm; maximum width 1.9–2.3 mm. Body broadly oval, slightly parallel-sided in the middle, moderately convex. Dorsum shiny. Head black. Pronotum yellowish to reddish brown, with an M-shaped black patch on disc; the size and of the patch varies between individuals, sometimes the patch is connected along posterior margin of pronotum ( Fig. 21D ). Elytron yellowish to reddish brown, with all striae black throughout, elytral margin, base and interval of stria 1 black; elytron with a large black triangular patch lateromedially, reaching stria 3. Maxillary palpi and labial palpi yellowish brown; antennae yellowish brown with club darker. Prosternum, mesoventral plate, epipleura, legs and ventrites yellowish to reddish brown, other portion dark reddish brown to black.

Head. Dorsal surface with uniform dense and coarse crescent-shape punctures; interstices between punctures smooth.Anterior margin of clypeus with a marginal bead. Eyes of moderate size, separated by ca. 5× the width of one eye. Mentum subtrapezoid, ca. 1.5× as wide as long, slightly depressed anteromedially; anterior margin of mentum slightly concave; with sparse and very fine punctures ( Fig. 22A ). Posterior tentorial pits not distinctly depressed. Antennae with 9 antennomeres; antennal club (antennomeres 7–9) compact and densely pubescent. Maxillary palpomere 2 moderately swollen in apical half, longer than palpomere 3; palpomere 4 almost symmetrical, slightly longer than palpomere 3. Each maxilla with a sucking-disc shaped appendage in male.

Thorax. Pronotum widest posteriorly, gradually narrowed anteriad, with crescent-shape punctures as those on head. Lateral margins of pronotum narrowly rimmed, the rim overlapping anterior and posterior corners, anterior and almost whole posterior margin without rim. Prosternum gradually raised at middle portion and tectiform medially, with sharp median carina; prosternum pubescent, without ridge; prosternal process finely notched posteriorly ( Fig. 22B ). Antennal groove broad, outer lateral margin strongly convex ( Fig. 22B ). Mesoventral plate narrowly elongate, surface slightly convex and shining; ca. 8× as long as wide, posterior apex overlapping the anterior ridge of metaventrite in a single point ( Fig. 22C ). Scutellar shield in shape of equilateral triangle, longer than wide, with punctures as those on pronotum. Elytra widest at anterior third; each elytron with 10 rows of punctate striae, striae moderately impressed; striae 6, 8 and 9 not reaching anterior margin of elytron; stria 10 short, only ending at posterior third of elytron; intervals of striae flat, with fine ground punctures, intervals between punctures glabrous. Epipleuron wedge-shaped and strongly oblique at anterior half of elytron. Central area of metaventrite uniformly punctate and bare, lateral areas of metaventrite densely pubescent, without coarse punctures; anterior ridge of metaventrite strongly bent backwards at anterolateral corner and forming a distinct arcuate ridge; metaventrite with complete femoral lines crossing the arcuate ridges and reaching anterolateral corners of metaventrite; anterior ridge of metaventrite continuous with the arcuate ridge at the crossing point ( Fig. 22D ).

Legs. Profemora bare ventrally, with very fine punctures; mesofemora with coarser setiferous punctures than those on metafemora. Tibiae with small lateral spines. Tarsi with sparse gold ventral setae, first metatarsomere about as long as metatarsomeres 2–3 combined.

Abdomen. Abdominal ventrites densely pubescent. First ventrite sharply carinate medially, without series of short longitudinal sculptures basally ( Fig. 22E ).

Male genitalia. Paramere widest basally, gradually narrowing towards apical fourth and slightly widened subapically, then gradually narrowing towards apex; apex of paramere bluntly pointed, curved inwards; inner face of paramere with a fringe of long setae subapically and several apical setae ( Fig. 21E, G ). Phallobase slightly shorter than parameres; nearly parallel sided, manubrium gradually narrowed and asymmetrical at the base ( Fig. 21E, G ). Median lobe widest in the middle and gradually narrowing towards apex; apex bluntly pointed ( Fig. 21F ). Median projection of sternite 9 narrowed medially, slightly expanded subapically and narrowed anteriad; lateral struts slightly longer than median portion ( Fig. 21H ).

Biology. This species occurs in the forests. Adults are attracted in large numbers to monkey or human excrement or dead animal bodies. This species co-occurs with Peltocercyon taylorae sp. nov. in Laos.

Etymology. The species name is derived from Latin macula (spot) and penne (wing), referring to the spotted elytra of this species.

Remarks. This species belongs to the Peltocercyon splendidus group and strongly resembles the other species in the group. It can be distinguished from them by the pronotum with a M-shaped large black patch on the disc ( Fig. 21A, D ) (pronotum mostly black, with yellow patches laterally in P. splendidus sp. nov. and P. medogensis sp. nov., Figs 23A , 25A, D ; pronotum yellowish brown with median black patch in P. taylorae sp. nov., Fig. 27A ).

Distribution ( Fig. 42 ). China (Chongqing, Guangxi, Guizhou, Sichuan, Taiwan), Laos (Houaphanh, Phongsaly), Vietnam (Tam Dao), India (northeast India).

Figures

FIGURE 21. Peltocercyon maculipennis sp. nov. A–D: habitus (A–C: specimen from Guangxi, China. D: specimen from Houaphanh, Laos). E–H: male genitalia. A, D: dorsal view. B: lateral view. C: ventral view. E: aedeagus. F: median lobe. G: tegmen, H: sternite 9. Scale bars 0.5 mm.

FIGURE 22. SEM photos of Peltocercyon maculipennis sp. nov. A: mentum and posterior tentorial pits of head. B: ventral view of prothorax. C: mesoventral plate and central area of metaventrite. D: right portion of metaventrite. E: first abdominal ventrite.

FIGURE 23. Peltocercyon medogensis sp. nov. (holotype). A–C: habitus. D–G: male genitalia.A: dorsal view. B: lateral view. C: ventral view. D: aedeagus. E: median lobe. F: tegmen, G: sternite 9. Scale bars 0.5 mm.

FIGURE 25. Peltocercyon splendidus sp. nov. A–D: habitus. (A–C: holotype, D: specimen from Sichuan, China) E–H: male genitalia.A, D: dorsal view. B: lateral view. C: ventral view. E: aedeagus. F: median lobe. G: tegmen, H: sternite 9. Scale bars 0.5 mm.

FIGURE 27. Peltocercyon taylorae sp. nov. (holotype) A–C: habitus. D–G: male genitalia. A: dorsal view. B: lateral view. C: ventral view. D: aedeagus. E: median lobe. F: tegmen, G: sternite 9. Scale bars 0.5 mm.

FIGURE 42. Distribution map of species in Peltocercyon splendidus group.