Peltocercyon medogensis 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 : 44-47

publication ID	https://doi.org/10.11646/zootaxa.5671.1.1
publication LSID	lsid:zoobank.org:pub:60D33D8C-BDC2-4C2A-B840-90014815E8CB
DOI	https://doi.org/10.5281/zenodo.16981932
persistent identifier	https://treatment.plazi.org/id/1032930E-FFA9-6B02-FF2C-2734B581ED89
treatment provided by	Plazi
scientific name	Peltocercyon medogensis Mai, Jia, Ryndevich
status	sp. nov.

Treatment

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

Figs 23A–G View FIGURE 23 , 24A–D View FIGURE 24 .

Type material examined. Holotype: male ( SYSU), “ Xizang, Nyingchi City (= Linzhi ), Medog County / Forest behind the Renqingbeng Temple (仁ª崩*后Ɯ) / 2104 m / 29.3086°N, 95.3471°E / 18.VI.2023 / Zuqi Mai & Wenkai Kou leg. // Primary forest , flight intercept trap with rotten jackfruits, bamboo shoots and human shit around” GoogleMaps . Paratypes: 2 females ( SYSU, NMP), same data as the holotype GoogleMaps .

Diagnosis. Length 3.3–3.5 mm. Head and pronotum black, pronotum with yellow patches laterally; elytron with a large black patch lateromedially, reaching elytral suture ( Fig. 23A View FIGURE 23 ). Pronotum with uniform crescent-shaped punctures. Elytra shiny, spaces between ground punctation smooth. Mentum with sparse and fine punctures ( Fig. 24A View FIGURE 24 ). Posterior tentorial pits without distinct depressions ( Fig. 24A View FIGURE 24 ). Prosternum tectiform medially; lateral portion with sparse and fine setae, without ridge; prosternal process finely notched posteriorly ( Fig. 24B View FIGURE 24 ). Antennal groove narrow ( Fig. 24B View FIGURE 24 ). Mesoventral plate spindle-shaped ( Fig. 24C View FIGURE 24 ). Arcuate ridge of metaventrite distinct, strongly bent backwards. Lateral areas of metaventrite without coarse punctures ( Fig. 24C View FIGURE 24 ). First abdominal ventrite without longitudinal sculptures basally. ( Fig. 24D View FIGURE 24 ). Male genitalia ( Fig. 23D–G View FIGURE 23 ): paramere slightly widened subapically and then gradually narrowing towards apex, apex rounded and straight; inner face of paramere with a fringe of long setae subapically and a few apical setae ( Fig. 23D, F View FIGURE 23 ). Median lobe broad and almost paralleled laterally, apex obtuse ( Fig. 23E View FIGURE 23 ).

Description. Form and Colour ( Fig. 23A–C View FIGURE 23 ). Total length 3.3–3.5 mm; maximum width 2.0– 2.3 mm. Body broadly oval, slightly parallel-sided in the middle, moderately convex. Dorsum shiny. Head and pronotum black, pronotum with two narrow yellow patches laterally. Elytron with a very large black triangular patch lateromedially, reaching elytral suture and connected with another one; elytral margin, base, interval of stria 1 and all striae black; remaining areas of elytra yellowish brown, divided into four triangles by the black areas. Maxillary and labial palpi yellowish brown; antennae yellowish brown with club darker. Prosternum, mesoventral plate, epipleura, legs and posterior margins of ventrites yellowish brown, other areas dark 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 fine punctures ( Fig. 24A View FIGURE 24 ). 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, pubescent, without ridge; prosternal process finely notched posteriorly ( Fig. 24B View FIGURE 24 ). Antennal groove narrow, outer lateral margin moderately convex ( Fig. 24B View FIGURE 24 ). 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. 24C View FIGURE 24 ). 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. 24C View FIGURE 24 ).

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. 24D View FIGURE 24 ).

Male genitalia. Paramere widest basally, gradually narrowing towards apical fourth and slightly widen subapically, then gradually narrowing towards apex; apex of paramere rounded; inner face of paramere with a fringe of long setae subapically and several apical setae ( Fig. 23D, F View FIGURE 23 ). Phallobase slightly shorter than parameres; nearly parallel sided, manubrium gradually narrowed and asymmetrical at the base ( Fig. 23D, F View FIGURE 23 ). Median lobe widest in the middle and broad, almost paralleled laterally; abruptly narrowed subapically with a rounded and obtuse apex; gonopore triangular, situated subapically ( Fig. 23E View FIGURE 23 ). Median projection of sternite 9 gradually narrowing apicad and rounded at the base; lateral struts slightly longer than median portion ( Fig. 23G View FIGURE 23 ).

Biology. This species occurs in high mountain forest. Adults are attracted by a strong smell of decaying organic matter including excrement.

Etymology. This species is named after the type locality, Medog county in Xizang, China.

Remarks. This species belongs to the Peltocercyon splendidus group. It is most similar to Peltocercyon splendidus sp. nov., and can be distinguished from the latter by its elytral triangular black patch very large, reaching elytral suture and connected at the middle ( Fig. 23A View FIGURE 23 ) (triangular black patches only reaching elytral stria 3 and separated medially in P. splendidus sp. nov., Fig. 25A, D View FIGURE 25 ), and the median lobe of aedeagus broad and almost parallel-sided ( Fig. 23E View FIGURE 23 ) (slender, widest in the middle and gradually narrowing towards apex in P. splendidus sp. nov., Fig. 25F View FIGURE 25 ).