Copelatus diversistriatus Jiang, Hájek & Jia, 2022

Jiang, Zhuo-Yin, Zhao, Shuang, Yang, Zhen-Yu, Jia, Feng-Long & Hájek, Jiří, 2022, A review of Copelatus Erichson, 1832 of Mainland China, with description of ten new species from the japonicus complex (Coleoptera: Dytiscidae: Copelatinae), Zootaxa 5124 (3), pp. 251-295 : 256-258

Copelatus diversistriatus Jiang, Hájek & Jia , sp. nov.

( Figs 5–6 , 37–38 )

Type locality. China, Yunnan Province, Pu’er City, Laiyanghe, Xinzhai village , ca. 22°37′52″N 101°07′55″E ; 1487 m.

Type material. Holotype, ♂ ( SYSU), labelled: “ CHINA: Yunnan Province / Pu’er City, Laiyanghe / Xinzhai Village / 22.631N, 101.132E / 1487 m, 21.v.2011 / Keqing Song leg. [p] // HOLOTYPE / COPELATUS / diversistriatus sp. nov. / Jiang, Hájek & Jia det. 2021 [red label, p]” . Paratypes: 2 ♀, same label data as holotype ( SYSU) ; 1 ♂, labelled: “ China: Yunnan, Lai yang he / Xin zhai, 1481m, 21.v.2011, / N22.63161 E101.13255, / S. Keqing (IRS 1399) [p] // DNA / M.Balke / 6587 [p, green typing]” ( ZSMG) ; 1 ♂, labelled: “ YUNNAN 1500-2500m / 25.22N 98.49E 17-24.5 / GAOLIGONG mts. / Vít Kubáň leg. 1995 [p]” ( ZSMG) ; 6 ♂, 11 ♀, labelled: “ China, Yünnan prov.; / Gaoligong Shan; 2800m a.s.l. / ca 30km E Tengchong; meadow / holokren [ Sic !] spring, muddy pools / 24.10.1999, leg. J. Šťastný [p]” ( JSCL) ; 1 ♀, labelled: “ CHINA: Yünnan, Xishuangbanna / ca. 10km NW Menglun / 7.11.1999, ca. 700 m / leg. Jäch, et al. (CWBS 359) [p]” ( NHMW) ; 2 ♂, 8 ♀, labelled: “ CHINA: Yünnan, Xishuangbanna / ca. 10km NW Menglun / 7.11.1999, ca. 700 - 800 m / leg. Jäch, et al. (CWBS 360) [p]” ( NHMW) ; 3 ♂, labelled: “ CHINA: Yunnan province, / REHAI hot springs, 5.VI. 2007 / 6 km SW of TENGCHONG, / 24°57.1′N 098°26.2′, 1400 m, / J. Hájek & J. Růžička leg. // individually collected in small / pool with clay bottom, and on / plants and shrubs margin of / grove above the rice fields [p]” ( NMPC) ; 1 ♂, labelled: “ CHINA: Yunnan Province / Baoshan City / Gaoligong Nature Park / 24.91N, 98.81E / 1751 m, 22.v.2016 / Y. Tang & R. Zhang leg. [p]” ( SYSU) ; 1 ♂, labelled: “ CHINA: YUNNAN Prov. / 6 km SSW Tengchong / Rehai Hot Springs / 24°56.9′N 98°26.9′E, 1445 m / J. Hájek & J. Růžička leg. // 22.vi.2016; individually from / vegetation, in artificial watering / pools and in stream; / border of ruderal and orchards [p]” ( NMPC) ; 21 ♂, 13 ♀, labelled: “ CHINA: YUNNAN PROV. / 14 km SE Tengchong / Renjiafen env., 2025-2145 m / 24°56.0-5′N, 98°35.0-7′E, / J. Hájek & J. Růžička leg. // 23.vi.2016 / individually from pool / border of ruderal, orchards and / secondary mixed forest [p]” ( IZCAS, NHRS, NMPC, SNUC, ZFMK) ; 1 ♂, 1 ♀, labelled: “ CHINA: YUNNAN Prov. / TONGBIGUAN env., 1340-1380 m / 24°36.0-37.0′N, 97°35.1-4′E, / J. Hájek, J. Růžička leg. // 24.-26.vi.2016; individually from / ruderal vegetation, from fungi / on dead wood, in Bos excre- / ments, in puddles near river [p]” ( NMPC) ; 3 ♂, 5 ♀, labelled: “ CHINA: YUNNAN Prov. / 6.5- 5.2 km W Tongbiguan / 24°36.6-8′N, 97°35.5-36.4′E, / 1290-1325 m / J. Hájek & J. Růžička leg. // 25.+ 27.vi.2016; / individually from puddle, / vegetation, fungi; / broadleaved tropical forest [p]” ( NMPC) ; 1 ♂, labelled: “ CHINA: Yunnan Province / Lvchun County / roadside ditches and terraces / 22.8856N, 102.3264E / 1443.5 m, 1.v.2021 / Z. Jiang, Z. Yang, Z. Mai & / B. Huang leg. [p]” ( SYSU) . All paratypes with the appropriate printed red label .

Additional material examined. LAOS: 1 ♂, 1 ♀, Attapeu Prov., Annam Highlands Mts., Dong Amphan NBCA, Nong fa (crater lake) env., 15°05.9′N 107°25.6′E, 1160 m, 30.iv.-6.v.2010, J. Hájek leg. ( NMPC) . MYANMAR: 2 ♂, Shan State, 35 km N Aungban , 20°55.20′N 96°33.60′E, 1320 m, flight intercept trap, 31.v.-8.vi.2002 ( NHMW, NMPC) ; 85 spec., Shan State, NE Mintaingbin Forest Camp, 20°55.640′N 96°33.634′E, 1290 m, puddles, 14.- 20.vi.2004, H. Shaverdo leg. ( NHMW, NMPC) ; 81 spec., Shan State, SE Mintaingbin Forest Camp, forest pools and leaf litter near stream, 17.vi.2004, H. Shaverdo leg. ( NHMW, NMPC) ; 52 spec., Mandalay Reg., Mogok Township, S Panlin vill., W slopes of Mt. Taung Mae , ca. °58′09.7″N 96°27′11″E, 1710 m, 12.vi.2014, H. Schillhammer leg. ( NHMW) . THAILAND: 1 ♀, Nakhon Ratchasima Prov., Khao Yai NP, 8.-10.xii.2011, J. Šťastný leg. ( ZSMG) ; 1 ♂, Phitsanulok Prov., Nakhon Thai Distr., Phu Hin NP, Rong Kla , 16°59′49.1″N 101°00′34.8″E, in waterfall, 7.iii.2016, A. Damaška leg. ( NMPC) . See the Variability section .

Description of male holotype. Habitus ( Fig. 5 ) oblong oval, with continuous outline, broadest in anterior 1/3 of elytral length, slightly convex. Dorsal surface shiny.

Colouration. Head dark brown, clypeus and two oval spots on vertex rufous; pronotum dark brown, laterally broadly orange; elytra brown, laterally somewhat paler, with moderately broad, irregularly shaped, basal orange band not reaching suture; appendages orange-brown; ventral side dark brown to black.

Head. Moderately broad, ca. 0.62× width of pronotum, trapezoidal. Anterior margin of clypeus indistinctly concave. Antenna with antennomeres long and slender. Reticulation consisting of moderately deeply impressed polygonal isodiametric meshes. Punctation double, consisting of coarse setigerous punctures, and fine punctures spread sparsely on surface; row of coarse punctures present alongside inner margin of eyes, several punctures present at frontal level of eyes, and antero-laterally to eyes in fronto-clypeal depressions.

Pronotum. Strongly transverse (width/length ratio = 3.03), broadest between posterior angles, lateral margins moderately curved. Lateral sides with beading very thin and indistinct. Reticulation similar to that of head. Punctation double; rows of coarse setigerous punctures present along anterior margin, close to lateral sides, several punctures present also in shallow baso-lateral depressions along basal margin; fine puncture smaller and sparser than on head, spread throughout whole surface. Pronotum, except for centre of disc, with numerous, irregularly distributed short longitudinal or oblique strioles. Centre of disc with shallowly impressed median longitudinal smooth line.

Elytra. Base of elytra as broad as pronotal base; lateral margins of elytra slightly diverging in basal third, then distinctly narrowing to apex. Ten discal and one submarginal longitudinal striae present on each elytron: all striae beginning more or less at base; striae 1, 3, 5, 7, 9–10 complete; stria 1 longest, ending close to apex; striae 3, 5, 7, 9 somewhat shorter, ending subapically, stria 10 ending at apical fourth; striae 2, 4, 6 short, presented only in basal third of elytral mid-length, apically usually fragmented into several short strioles; stria 8 shortest, present only in basal fourth of elytra; submarginal stria long, beginning at elytral mid-length and ending at apical fourth. Reticulation similar to that of head and pronotum, but less impressed. Punctation consisting of coarse setigerous punctures and very fine sparse punctures; coarse punctures present along elytral striae and lateral margins of elytra.

Legs. Protibia modified, angled near base, distinctly broadened anteriorly, club shaped. Pro- and mesotarsomeres 1–3 distinctly broadened, with four rows of adhesive setae on their ventral side; claws simple.

Ventral side. Prosternum sinuate anteriorly, obtusely keeled medially. Prosternal process shortly lanceolate, in cross-section convex, apex obtuse; process distinctly bordered laterally; reticulation consisting of shallow, hardly perceptible polygonal meshes. Metaventrite with microsculpture consisting of polygonal meshes; lateral parts of metaventrite (“metasternal wings”) tongue-shaped, slender. Metacoxal lines nearly complete, absent only close to metaventrite. Metacoxal plates covered with long, longitudinal strioles; reticulation consisting of elongate, oblique polygonal meshes. Metacoxal processes rounded at posterior margin. Abdominal ventrites I–II with longitudinal strioles; ventrites III–IV with oblique strioles laterally. Abdominal reticulation consisting of elongate polygonal meshes, longitudinal on ventrites I–II, oblique on ventrite III and transverse on ventrites IV–VI. Punctation consisting of fine, sparsely distributed punctures; coarse setigerous punctures present medially on ventrite III, and medio-laterally on ventrite VI.

Male genitalia. Median lobe of aedeagus in lateral view sickle-shaped; broad in basal three quarters, slightly narrowing in apical quarter; curved in basal third, then almost parallel-sided until apical quarter, and then curved to obtusely pointed apex ( Fig. 37 ); lateral carina of median lobe with small spines in apical half ( Fig. 37 aa). Parameres moderately broad, ‘C’-shaped; apex short and broad; apical lobes long, club-shaped ( Fig. 38 ).

Female. Identical to male in habitus. Protibia simple, not angled basally and only slightly broadened distally; pro- and mesotarsomeres not broadened, without adhesive setae. Short irregular strioles present between stria 1 and lateral margin in anterior third of elytra in some specimens.

Variability. The specimens of the new species vary slightly in dorsal surface colouration, especially in extent of orange basal elytral band, which may be comb-like shaped. The specimens vary also in extent of striolation on pronotum. However, the most apparent variability is in the elytral striation: short striae 2, 4, 6, 8 vary in length, occupying from one fourth to nearly a half of elytral length; those striae may be also fragmented into several short strioles, or partly or completely reduced, thus the beetles have only six dorsal elytral striae (see below). On the other hand, several short strioles may present between regular striae.

While most of the specimens from Yunnan and specimens from central Thailand agree with the holotype in the elytral striation, one population from Yunnan (6.5– 5.2 km W Tongbiguan) and the specimens from southern Laos have the even elytral striae 2, 4, 6, 8 partly reduced, and the majority of specimens from Myanmar have elytra with six discal striae only ( Fig. 6 ). The male genitalia are identical in all studied specimens. Although we have no doubts that all material belongs to one nominal species, due to the large variability between populations and extended area of distribution, we have decided to exclude the specimens from outside Yunnan province, China from the type material .

Measurements. TL: 4.7–5.5 mm (mean value: 5.2 ± 0.2 mm); holotype: 5.2 mm. TL-h: 4.3–5.0 mm (mean value: 4.7 ± 0.2 mm); holotype: 4.8 mm. MW: 2.3–2.8 mm (mean value: 2.6 ± 0.1 mm); holotype: 2.6 mm.

Differential diagnosis. Based on the presence of 10 dorsal striae and a submarginal stria on each elytron, the new species can be classified within the C. erichsonii Guérin-Méneville species group. This large group is in the Oriental region represented with only three species from India and Indonesia respectively ( Nilsson & Hájek 2022a). From all these species, C. diversistriatus sp. nov. clearly differs in the short even elytral striae 2, 4, 6 and 8.

However, the reduction of elytral striae to six indicates that C. diversistriatus sp. nov. is in fact more closely related to species of the C. japonicus Sharp complex in the C. irinus species group. This fact is confirmed with the molecular analysis (M. Balke et al., unpublished data).The similar reduction of elytral striae was recently documented and discussed by Manuel et al. (2018) in Neotropical Copelatus . Within the members of the C. japonicus complex, the specimens of the new species with six dorsal striae on each elytron can be undoubtedly recognized only based on the median lobe of male genitalia, which is simple, sickle-shaped, broad in basal three fourths, and then slightly narrowed to obtusely pointed apex.

Collection details. Copelatus diversistriatus sp. nov. was collected predominantly in small temporary pools or ditches with muddy bottom, both densely vegetated and without any vegetation ( Fig. 73 ). In western Yunnan, it was repeatedly collected syntopically with C. malaisei Guignot, 1954 .

Etymology. The species name is composed from the Latin adjectives diversus (-a, -um) (= diverse), and striatus (-a, -um) (= with striae), referring to the diverse length of odd and even elytral striae.

Distribution. Widely distributed species, recorded from southwest China (southern Yunnan) ( Fig. 81 ), neighbouring Shan State in eastern Myanmar, as well as Mandalay Region in central Myanmar, central Thailand (Nakhon Ratchasima and Phitsanulok provinces) to southern Laos (Attapeu province).

Figures

FIGURE 81. Map of distribution of Copelatus in China Mainland.

FIGURES 5–8. Habitus of Copelatus in China. 5. C. diversistriatus sp. nov. (holotype ♂; Pu’er, Yunnan); 6. C. diversistriatus sp. nov. (♂; NE Mintaingbin Forest Camp, Myanmar); 7. C. felicis sp. nov. (holotype ♂; Baishui, Yunnan); 8. C. japonicus (♂; Shanghai). Scale bar 1 mm.

FIGURES 29–38. Male genitalia of Copelatus. 29, 31, 33, 35, 37. median lobe in lateral view; 30, 32, 34, 36, 38. paramere. 29–30. C. bacchusi (Hainan); 31. C. chinensis (a. Lakeshan, Zhejiang; b. Yanjiajie, Hunan; c. Tainmushan, Zhejiang); 32. C. chinensis (Tianmushan, Zhejiang); 33. C. dentatipenis sp. nov. (a. holotype, Jinggangshan, Jiangxi; b. Guadun, Fujian; c. Mangshan, Hunan); 34. C. dentatipenis sp. nov. (holotype, Jinggangshan, Jiangxi); 35–36. C. felicis sp. nov. (holotype, Baishui, Yunnan); 37. C. diversistriatus sp. nov. (a. holotype, Pu’er, Yunnan; aa. detail of lateral carina with spines; b. Attapeu, Laos; c. NE Mintaingbin Forest Camp, Myanmar); 38. C. diversistriatus sp. nov. (holotype, Pu’er, Yunnan). Scale bar 0.5 mm.

FIGURES 71–78. Habitat of Copelatus in China. 71. Tianmushan, Zhejiang (C. chinensis); 72. Jinggangshan, Jiangxi (C. dentatipenis sp. nov.); 73. Tongbiguan, Yunnan (C. diversistriatus sp. nov.). 74. Dadongshan, Guangdong (C. nanlingensis sp. nov.); 75. Macao (C. oblitus in wet soil); 76. Dali, Yunnan (C. rimosus); 77. Kongshu, Yunnan (C. rosulae sp. nov.); 78. Danxiashan, Guangdong (C. oblitus and C. zimmermanni).