Peltocercyon vividus ( d'Orchymont, 1925 ), 2025

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 : 37-40

publication ID	https://doi.org/10.11646/zootaxa.5671.1.1
publication LSID	lsid:zoobank.org:pub:60D33D8C-BDC2-4C2A-B840-90014815E8CB
persistent identifier	https://treatment.plazi.org/id/1032930E-FFA6-6B0B-FF2C-2238B609EFFD
treatment provided by	Plazi
scientific name	Peltocercyon vividus ( d'Orchymont, 1925 )
status	comb. nov.

Treatment

Peltocercyon vividus ( d'Orchymont, 1925) , comb. nov.

Figs 19A–G View FIGURE 19 , 20A–D View FIGURE 20 , 33D–F View FIGURE 33

Cercyon (s. str.) vividus d'Orchymont, 1925: 279 View in CoL . Type locality: Hoa Binh, Tonkin.

Cercyon (Clinocercyon) vividus Orchymont View in CoL ; Orchymont, 1942: 2.

Type material examined. Holotype ( Fig. 33D–F View FIGURE 33 ): male ( IRSNB), “ Hoa Binh / Tonkin / de Cooman // TYPE // Cercyon (s. str.) / vividus / Type // Coll. R. I. Sc. N. B ” . Paratype: 1 male ( IRSNB), “ Hoa Binh / Tonkin / de Cooman // Para- / type”

Additional material: MALAYSIA: 6 spec. ( NMP), “W MALAYSIA: Selangor / Ulu Gombak field studies centre (22 km NE Kuala Lumpur) / 3°19’32’’N, 101°45’16’’E / lgt. Damir Kovac, 2007 // BS3107 / 21.VIII.2007 / felled young bamboo shoot ( Gigantochloa scortechinii ) laying on the ground” GoogleMaps . THAILAND: 5 spec. ( NMP), “THAILAND: Mae Hong Son Pang Mapha dist., 5 km SE of Soppong [= Pang Mapha] / Ban Pha Mon env., Damir Kovac lgt. 2006 // B195/06 / 1.VIII.2006 / felled young bamboo shoot ( Dendrocalamus giganteus )” . LAOS: 4 males, 1 female ( NHMB), “LAOS-N ( Louangphra-bang ), 11–21.Ⅴ.2002, 19°35’N 101°58’E, THONG KHAN, 750 m, Vit KubÁň leg. // Collection Naturhistorisches Museum Basel” GoogleMaps ; INDONESIA: 1 female ( NMEG). “INDONESIA N-Sulawesi / vlc. Boyong Atas , ca. 550 m / 1°05’50’’N, 124°25’26’’E / 21.II.2009 leg. A. Weigel (009)” GoogleMaps

Diagnosis. Length 3.0– 3.3 mm. Dorsum dark reddish brown ( Fig. 19A View FIGURE 19 ). Pronotum with uniform crescent-shaped punctures. Elytra shiny, spaces between ground punctation smooth. Mentum with dense microsculpture and coarse punctures ( Fig. 20A View FIGURE 20 ). Posterior tentorial pits not distinctly depressed ( Fig. 20A View FIGURE 20 ). Prosternum tectiform medially; lateral portion without ridge and shagreened; prosternal process deeply notched posteriorly ( Fig. 20B View FIGURE 20 ). Antennal groove moderate in size ( Fig. 20B View FIGURE 20 ). Mesoventral plate spindle-shaped ( Fig. 20C View FIGURE 20 ). Arcuate ridge of metaventrite strongly bent backwards and distinct ( Fig. 20C View FIGURE 20 ). Lateral areas of metaventrite with scattered coarse punctures ( Fig. 20C View FIGURE 20 ). First abdominal ventrite with some longitudinal sculpture basally ( Fig. 20D View FIGURE 20 ). Male genitalia ( Fig. 19D–G View FIGURE 19 ): paramere slightly expanded and obliquely truncate apically; inner face of paramere without fringe of setae ( Fig. 19D View FIGURE 19 ). Median lobe widest in basal third and gradually narrowing towards apex ( Fig. 19E View FIGURE 19 ).

Redescription. Form and Colour ( Fig. 19A–C View FIGURE 19 ). Total length 3.0– 3.3 mm; maximum width 1.7–2.1 mm. Body broadly oval, not parallel-sided in the middle, moderately convex. Dorsum dark reddish brown and shiny. Maxillary and labial palpi yellowish brown; antennae yellowish brown with club darker. Ventral surface reddish brown to reddish black, legs reddish brown.

Head. Dorsal surface with uniformly dense and coarse crescent-shaped 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. 2.0× as wide as long, slightly depressed anteromedially; anterior margin of mentum slightly concave; with dense transverse microsculpture and coarse punctures ( Fig. 20A View FIGURE 20 ). Posterior tentorial pits without distinct depressions. Antennae with 9 antennomeres; antennal club (antennomeres 7–9) compact and densely pubescent. Maxillary palpomere 2 strongly 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 finer and sparser crescent-shape punctures than 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; lateral portion of prosternum without ridge and shagreened; prosternal process deeply notched posteriorly ( Fig. 20B View FIGURE 20 ). Antennal grooves moderate in size, outer lateral margin moderately convex ( Fig. 20B View FIGURE 20 ). Mesoventral plate spindle-shaped and elongate, surface slightly convex and shining; ca. 5–6 × as long as wide, posterior apex overlapping the anterior ridge of metaventrite in a single point ( Fig. 20C View FIGURE 20 ). Scutellar shield triangular, longer than wide, with punctures finer than 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 smooth. Epipleuron wedge-shaped and strongly oblique at anterior half of elytron. Central area of metaventrite uniformly punctate and glabrous, lateral areas of metaventrite densely pubescent and with some coarse punctures; anterior ridge of metaventrite strongly bent backwards at anterolateral corner and forming an arcuate ridge; metaventrite with complete femoral lines crossing the anterolateral arcuate ridges and reaching anterolateral corners of metaventrite ( Fig. 20C View FIGURE 20 ). Anterior ridge of metaventrite continuous with the arcuate ridge at the crossing point ( Fig. 20C View FIGURE 20 ).

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, with a series of short longitudinal sculptures basally ( Fig. 20D View FIGURE 20 ), more rough than other ventrites.

Male genitalia. Paramere widest basally, slightly expanded and obliquely truncate apically; inner face of paramere without fringe of setae ( Fig. 19D, F View FIGURE 19 ). Phallobase shorter than parameres; nearly parallel sided, manubrium gradually narrowed and asymmetrical at the base ( Fig. 19D, F View FIGURE 19 ). Median lobe widest in basal third, gradually narrowing towards apex; gonopore triangular, situated subapically ( Fig. 19E View FIGURE 19 ). Median projection of sternite 9 slender and rounded basally; lateral struts slightly longer than median portion ( Fig. 19G View FIGURE 19 ).

Biology. Occurs in forests. Based on the label data, adults seem to be attracted to fresh and decaying bamboo shoots.

Remarks. This species is similar to P. basirugosus sp. nov. in form and colour and can be distinguished from it by depressed lateral portions of prosternum with shagreen ( Fig. 20B View FIGURE 20 ) (smooth in P. basirugosus sp. nov. ( Fig. 6B View FIGURE 6 )), anterior ridge of metaventrite continuous with the arcuate ridge at the crossing point of femoral line ( Fig. 20C View FIGURE 20 ) (discontinuous with the arcuate ridge in P. basirugosus sp. nov. ( Fig. 6D View FIGURE 6 )), and the paramere only slightly expanded apically ( Fig. 19F View FIGURE 19 ) (paramere strongly expanded apically in P. basirugosus sp. nov. ( Fig. 5F View FIGURE 5 )).