Copelatus tengchongensis Hájek, Jiang & 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 : 272-273

Copelatus tengchongensis Hájek, Jiang & Jia sp. nov.

( Figs 23–24 , 63–64 )

Type locality. China, Yunnan Province, 12 km NE Tengchong, Beihai Wetlands, Zing Hai lake env., ca. 25°07.5′N 98°33.3′E, ca. 1730 m .

Type material. Holotype ♂ ( NMPC), labelled: “ China, Yünnan prov. / 10 km NE Tengchong; Behai [ Sic ! See the type locality.] / ZingHai lake env; / small flowing pools, dense veget. / 27.10.1999, leg. J. Šťastný [p] // HOLOTYPE / COPELATUS / tengchongensis sp. nov. / Hájek, Jiang & Jia det. 2021 [red label, p]” . Paratypes: 2 ♂, 4 ♀, same label data as holotype ( JSCL, NMPC) ; 7 ♂, 7 ♀, labelled: “ CHINA (Yunnan) / Baoshan Pref., Gaoligong Shan / 65 km NNE Tengchong 1750 m / 25°35′20″N, 98°40′21″E / (small brook at edge of sec. / mixed forest) / 27.VIII.2009 D.W.Wrase (10G) [p]” ( NMPC, SYSU, ZSMG). All paratypes with the respective paratype label .

Description of male holotype. Habitus ( Fig. 23 ) oblong-oval, with continuous outline, broadest in anterior 1/3 of elytral length, slightly convex. Dorsal surface shiny.

Colouration. Head brown blackish, clypeus reddish brown; pronotum brown blackish, laterally broadly orangebrown, anterior and posterior margin orange translucent; elytra dark brown, paler laterally, base with distinct, orange, comb-like shaped transverse band reaching neither lateral margin nor suture; appendages orange-brown; ventral side brown blackish.

Head. Moderately broad, ca. 0.63× width of pronotum, semicircular. 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; fine punctures smaller and sparser on clypeus, becoming larger and more dense posteriorly.

Pronotum. Transverse (width/length ratio = 2.69), broadest between posterior angles, lateral margins moderately curved. Lateral sides with beading very thin and indistinct. Reticulation similar to that of head. Punctation similar to that of head; rows of coarse setigerous punctures present along anterior margin, laterally close to sides, several punctures present also in shallow baso-lateral depressions along basal margin.Pronotum baso-laterally and especially laterally with irregular wrinkles and very few short longitudinal strioles. Centre of disc with shallowly impressed medial 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. Six discal and one submarginal longitudinal striae present on each elytron: striae 1 and 5 beginning slightly posteriorly to base; striae 2–4, 6 beginning at base; stria 1 longest, ending close to apex; striae 2–5 ending subapically, even striae generally shorter than odd striae; stria 6 ending at apical fourth; submarginal stria long, beginning before 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 not perceptible. Metaventrite with microsculpture consisting of polygonal meshes, laterally with oblique strioles; lateral parts of metaventrite (“metasternal wings”) tongue-shaped, slender. Metacoxal lines nearly complete, absent only close to metaventrite. Metacoxal plates covered with long, oblique strioles; reticulation consisting of elongate, longitudinal or oblique polygonal meshes. Metacoxal processes rounded at posterior margin. Abdominal ventrites I–II with longitudinal strioles; ventrites III–IV with oblique strioles laterally. Tuft of setae present antero-medially on ventrites III–V; ventrite VI with setigerous punctures laterally on either side.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.

Male genitalia. Median lobe of aedeagus in lateral view simple, sickle-shaped, broadest at mid-length due to shallow swelling on ventral side; in apical third narrowing continuously to pointed apex ( Fig. 63 ). Parameres moderately broad, ‘D’-shaped; apex short and broad; apical lobes long, club-shaped ( Fig. 64 ).

Female. Identical to male in habitus. Protibia simple, not angled basally and only slightly broadened distally; pro- and mesotarsomeres not broadened, without adhesive setae. Females dimorphic; smooth form differs from male in more developed striolation laterally on pronotum; striolate form submatt, with long strioles covering pronotum and elytra except for apical fifth ( Fig. 24 ).

Variability. All specimens of the type series are rather uniform. There is only slight variability in dorsal surface colouration, especially in extent and brightness of pale basal band on elytra. Minor variability can be seen also in number and length of strioles presenting laterally on pronotum.

Measurements. TL: 4.7–5.5 mm (mean value: 5.3 ± 0.2 mm); holotype: 5.0 mm. TL-h: 4.2–5.1 mm (mean value: 4.8 ± 0.2 mm); holotype: 4.5 mm. MW: 2.3–2.8 mm (mean value: 2.6 ± 0.1 mm); holotype: 2.5 mm.

Differential diagnosis. Based on the presence of six dorsal striae and a submarginal stria on each elytron, the new species can be classified within Copelatus irinus species group. Elongate habitus, complete elytral striation and male median lobe without distinct process place C. tengchongensis sp. nov. in the C. japonicus complex. Within the complex, the new species can be undoubtedly recognised only based on the shape of male genitalia: C. tengchongensis sp. nov. is characteristic with the median lobe broadest in midpart and the apical part only slightly narrowing to apex ( Fig. 63 ).

Etymology. The new species is named after its area of occurrence – Tengchong County, where both known localities of the species lie. The specific epithet is an adjective in the nominative singular.

Distribution. The species is so far known only from two close localities on western side of the Gaoligong mountains, western Yunnan, China ( Fig. 83 ).

Figures

FIGURE 83. Map of distribution of Copelatus in China Mainland.

FIGURES 21–24. Habitus of Copelatus in China. 21. C. sociennus (♂; Hengqin Island, Guangdong); 22. C. tenebrosus (♂; Hengqin Island, Guangdong); 23. C. tengchongensis sp. nov. (holotype ♂; Beihai, Yunnan); 24. C. tengchongensis sp. nov. (paratype ♀; Beihai, Yunnan). Scale bar 1 mm.

FIGURES 63–70. Male genitalia of Copelatus. 63, 65, 67, 69. median lobe in lateral view; 64, 66, 68, 70. paramere. 63–64. C. tengchongensis sp. nov. (holotype, Beihai, Yunnan); 65–66. C. weymarni (Honshu, Japan); 67–68. C. xiniudong sp. nov. (holotype, Xiniudong, Guizhou); 69–70. C. zimmermanni (Danxiashan, Guangdong). Scale bar 0.5 mm.