Clypeodytes (Hypoclypeus) limpidus Mai, Jiang, Hendrich & Jia, 2022

Mai, Zuqi, Jiang, Zhuoyin, Hu, Jian, Hendrich, Lars & Jia, Fenglong, 2022, A new species of Clypeodytes Régimbart, 1894 from China (Coleoptera, Dytiscidae: Bidessini), Zootaxa 5124 (1), pp. 50-60 : 51-53

Clypeodytes (Hypoclypeus) limpidus Mai, Jiang, Hendrich & Jia , sp. nov.

( Figs 1–13 )

Type locality: Xintanghe Village (25°9′35.7″N 98°14′42″E), 1.875 m, Tengchong County, Baoshan Prefecture, Yunnan, China .

Type material. HOLOTYPE: Male ( SYSU), “ China, Yunnan, Baoshan Prefecture, Tengchong County, Xintanghe Village (ŕä河村), 25°9′35.7″N 98°14′42″E, 1875 m, swamp with extensive vegetation, 12.V.2021, Zuqi Mai, Zhuoyin Jiang & Zhenming Yang leg.” PARATYPES: 39 exs ( SYSU), same data as the holotype ; 1 male and 8 exs ( NMPC), “ China, Yunnan province, GUDONG env., 8.VI.2007, YUNFENG SHAN Mt., 25°22.7′N, 098°25.4′E, 1825 m, J. Hájek & J. Růžička leg.” ; 1 female ( ZSM), “ China, Yunnan, Baoshan Prefecture , mountain range 22 km S Tengchong County, 24°49′29″ N 98°29′27″E, 1759 m, secondary forest, litter dead wood sifted, 2.6.2007, A. Pütz leg.”

Description of holotype. Total length 1.75 mm; maximum width 1.1 mm. Body short and robust, attenuated posteriad. Body surface with dense coarse punctures.

Coloration. Dorsal yellow brown to dark brown, with black patterns on basal pronotum and elytra ( Fig. 1 ). Ventral surface to large extent reddish brown ( Fig. 3 ). Legs, antennae, maxillary palps and labial palps yellowish ( Figs 1–4 ).

Head. Anterior margin of clypeus with thick bead ( Fig. 9 ). Frons with sparse fine setiferous punctures. Eyes large, posterior margin of eye attached to occipital line. Behind occipital line microreticulate ( Fig. 9 ).

Prothorax. Pronotum with setiferous punctures sparser than those on frons, becoming coarser posteriorly; lateral pronotal bead present; basal striae distinct ( Fig. 8 ). Prosternal process lanceolate and slightly tectiform and, apex broadly rounded.

Meso- and metathorax. Elytron without basal stria and without sutural line, with prominent longitudinal keel sublaterally ( Fig. 10 ) and a very weak keel more close to epipleuron; surface of elytron with dense coarse punctures, a few punctures with setae apically. Epipleuron in anterior third broad, becoming narrower posteriad; anteriorly with humeral cavity, limited posteriorly by an oblique subhumeral carina ( Fig. 11 ). Hind wings well developed. Anepisternum, metaventrite and metacoxa with sparse setiferous punctures; metaventrite with a line of fine punctures left and right a mid-line (= discrimen; see Fig. 12 ). Metacoxal lines short, more or less parallel; distance between lines not much smaller than length of lines. Lobes of metacoxal processes not prominent.

Legs. Metatibia elongate, distally gradually expanded ( Fig. 8 ).

Abdomen. Ventrites 1–2 with coarse punctures similar to those on metacoxa. Ventrites 3–6 with finer punctation, near apex of last abdominal ventrite denser.

Male genitalia ( Figs 5–7 ). Median lobe of aedeagus in lateral view as in Fig. 6 ; apical portion straight and slender, nearly acicular. Paramere ( Fig. 7 ) two-segmented and with hook-shaped apex.

Variation. Total length 1.7–2.0 mm; maximum width 1.0– 1.15 mm; several paratypes with paler coloration on pronotum and elytra. If so, each elytron with two black spots separated from the dark pattern on upper side ( Figs 1–2 ).

Etymology. This specific name of the new species is the Latin adjective limpidus (= clear), referring to the species habitat, a swamp with limpid fresh water.

Distribution. Only known from three localities in western Yunnan close to the border to Myanmar. Baoshan is a prefecture-level city in China and the second-largest metropolitan area in western Yunnan province. It is located between the border of Myanmar and the Lanchang river (Mekong river).

Diagnosis. The new species can be easily recognized from the other known Chinese species C. bufo by its smaller size ( C. limpidus sp. nov. total length: 1.7–2.0 mm, C. bufo total length: 2.0– 2.3 mm), the dorsal coloration with black patterns on the basal part of the pronotum and on the elytra, the narrower shape of the pronotum, the more roundish habitus, and the shape of the median lobe ( Figs 5–7 , 15–17 ).

Habitat. At the type locality the new species was collected along the margins of a swamp with dense vegetation, situated in a valley ( Fig. 13A ). Here C. limpidus sp. nov. co-occurs with several other Dytiscidae : Hydroglyphus sp. , Hydaticus major Régimbart, 1899 , Hydrovatus sp. , Laccophilus sp. and Rhantus sp. Specimens from Yunfeng Shan were found in a deep, densely vegetated swampy pool ( Fig. 13B ). At this locality the new species was associated with Agabus amoenus sinuaticollis Régimbart, 1899 , Hydaticus bipunctatus Wehncke, 1876 , and H. major Régimbart, 1899 . The single specimen collected by A. Pütz in 2007 was obtained by sifting leaf litter and dead rotten wood.

Figures

FIGURE 13. Habitat of C. limpidus sp. nov. (A: Pool at Baoshan Prefecture, Tengchong County, near Xintanghe Village. B: Pool near Gudeng in Yunfeng Shan Mountains.).

FIGURES 1–4. Habitus of Clypeodytes limpidus sp. nov. 1–2: dorsal view (1: holotype, 2: a paratype with different coloration) 3: ventral view, 4: lateral view.

FIGURES 5–7. Male genitalia of Clypeodytes limpidus sp. nov. 5: ventral view of median lobe, 6: lateral view of median lobe, 7: lateral view of paramere.

FIGURES 8–12. SEM of Clypeodytes limpidus sp. nov. 8: dorsal view (arrows indicate the basal pronotal striae), 9: head and pronotum (white arrow indicates the anterior bead of clypeus; black arrow indicates the occipital line), 10: lateral view of elytron (arrows indicate the sublateral carina), 11: epipleuron with oblique subhumeral carina, 12: metaventrite with a line of fine punctures right and left of a mid-line (discrimen).

FIGURES 15–17. Male genitalia of Clypeodytes bufo (Sharp, 1890). 15: ventral view of median lobe (15b: tapered tip of median lobe), 16: lateral view of median lobe, 17: lateral view of paramere.