A new species and a new record of Pelthydrus Orchymont, 1919 from Yunnan, China (Coleoptera: Hydrophilidae: Hydrophilinae) Author Zhu, Bingyue Author Ji, Lanzhu Author Bian, Dongju text Zootaxa 2018 2018-06-20 4438 1 189 194 journal article 29846 10.11646/zootaxa.4438.1.12 21b9288c-7301-4b31-9fe1-6397eef9709f 1175-5326 1294265 5914EBFF-4C15-47B8-8866-50AD03D7E297 Pelthydrus (s. str.) ruiliensis sp. nov. ( Figs 1–2 , 5 , 8 ) Type material. Holotype (IAECAS) male: “ CHINA : Yunnan Province , Ruili City , Dayingjiang National Scenic Area , Moli Management Office , 24°06'N , 98°00'E , 127 m , 17. 10. 2016 , leg Wang, Peng & Sun” . Paratypes : 4 males (IAECAS), same data as holotype . Diagnosis. This species is similar to Pelthydrus sculpturatus Orchymont , but can be distinguished by its thinner body shape and the different shape of aedeagus: the parameres of new species are significantly longer than the phallobase, while the latter is the opposite; and the position of gonopore also differs. FIGURE 7. Distribution, Pelthydrus ruiliensis sp. nov. (○), Pelthydrus madli (Δ). Description. Habitus as in Figs. 1–2 . BL: 2.70–2.95 mm ; BW: 1.50–1.65 mm . Body elongated oval, slightly convex, semicircular in posterior portion, surface shiny, dark black; antennae, lateral margins of pronotum, labial palpi, maxillary palpi, tibiae and tarsi yellowish brown. Head trapezoidal, about 1.6 times as wide as long; surface microreticulate, with evenly distributed median-sized punctures and yellowish brown setae sparsely distributed around eyes; frontoclypeal suture distinct; anterior margin of clypeus somewhat arched in the middle. Pronotum trapezoidal, about 1.4 times as wide as long, anterior corners rounded, the lateral margins nearly straight; surface microreticulate around corners; median-sized ground punctures evenly distributed; yellowish brown setae sparsely distributed along lateral margins of anterior half. Elytra about 2.6 times as long as wide; broadest part at basal 0.4, then gradually narrowed posteriorly, ending with narrowly rounded apices that do not meet at midline; ground punctures which slightly larger than those on head densely distributed, serial punctures on both sides of elytra. Ventral surface reddish brown, mentum dark brown, somewhat rugulose; prosternum reddish brown with a median longitudinal carina; Mesoventrite with apically slightly rounded triangular plate and median longitudinal carina; metaventrite with a posterior teardrop-shaped, flat and smooth glabrous area; first sternite with a medial longitudinal carina not reaching posterior margin. Aedeagus ( Fig. 5 ). 0.52 mm long, nearly parallel-sided, parameres about 1.4 times as long as phallobase; median lobe wide, gradually narrowing from base, gonopore located at apex; parameres exceeding median lobe, with apex oblique and truncated, inner margin shorter than outer margin. FIGURE 8. Stream in Moli Falls, Yunnan Province, China. Habitat of Pelthydrus ruiliensis sp. n. . Photograph by Y. Peng. Distribution. Yunnan Province , China . Etymology. Named after the type locality, Ruili City, Yunnan Province , China . Habitat. As shown in Fig. 7 . Small stream, unpolluted, sand, shatters, bank with sand, shrubs and grass. Remarks. A newly generated partial sequences of cytochrome oxidase subunit I (COI) is deposited in GenBank under accession number MG554385 .