Dactylosternum salvazai Orchymont 1925
Creators: name: Mai, Zuqi
name: Hu, Jian
name: Minoshima, Yûsuke N.
name: Jia, Fenglong
name: Fikáček, Martin
Publisher: name: Zenodo
Year: 2022
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Coleoptera
Hydrophilidae
Dactylosternum
Dactylosternum salvazai

description: Dactylosternum salvazai Orchymont, 1925
(Figs. 8, 25, 53, 57, 61)
Dactylosternum Salvazai Orchymont, 1925: 272. Type locality: Laos, Ban Ban.
Type material: not examined.
Material examined. CHINA: Yunnan: 1 male (SYSU), Gaoligong Mountain, 2000 m, 23.VII.2012, Jishan Xu & Lingxiao Chang leg.; 4 spec. (SYSU), Yingjiang County, Xima Town, 2000m, light trap, VI.2019, Zhaoyang Tang leg.
Additional material examined. LAOS: 1 female (SMNH), Hua Phan Prov., Ban Saluei, Phu Phan Mt., 20°15′N, 104°02′E, 1500–2000 m, 26.IV–11.V.2001, J. Bezděk leg., coll. H. Hebauer, Dactylosternum salvazai Orch., det. F. Hebauer.
Diagnosis. Length 7.3 mm. Body broadly oval, slightly parallel-sided in anterior half of elytra (Fig. 8), moderately convex. Dorsal black, surface with fine punctures, comparatively shiny. Anterior margin of clypeus without marginal rim. Antenna brown, club compact. Elytron with sutural stria and ten distinct rows of serial punctures, all nearly reaching elytral base, serial punctures with reticulation in ca. posterior half, intervals of serial punctures with fine ground punctures, each puncture with a K/H-shape microsculpture especially in posterior half (Fig. 53). Anteromedial portion of metaventrite, behind metaventral process with a Λ- shape divergent ridge (Fig. 57). Posteromedial portion of ventrite 5 with mesh-like microsculpture, posterior margin of ventrite 5 with a stria behind the marginal bead, with median group of strong setae along marginal bead (Fig. 61). Aedeagus (Fig. 25): Phallobase shorter than parameres. Outer margin of parameres slightly and continuously convex, not sinuate. Median lobe a little shorter than parameres; ventral plate of the median lobe triangular, apex rounded, gonopore situated at apex of ventral plate (Fig. 25c), reaching almost apex of median lobe.
Redescription. Total length 7.3 mm; maximum width 4.8 mm; body broadly oval, moderately convex.
Coloration. Dorsal black, with lateral margin of elytron reddish brown (Fig. 8). Maxillary palps and antenna brown. Ventral black, legs reddish brown.
Head. Clypeus weakly convex, surface with dense and fine punctures, anterior portion with denser punctures. Interstices between punctures smooth. Anterior margin of clypeus without marginal rim. Frons with punctures sparser than those on clypeus. Eyes of moderate size, separated by ca. 5× as wide as one eye, distinctly emarginate anteriorly in lateral view, smooth medially. Maxilla with glabrous basistipes. Mentum transverse, glabrous, strongly impressed anteromedially, lateral sides with series of fine setae. Submentum reddish brown, pubescent. Labial palps rather stout, palpomere 1 minute, palpomere 2 strongly widened distally, with dense brush of long yellow setae on its inner face and distal margin, palpomere 3 longer than other ones. Antennal scapus longest, rather thick, ca. 7.5× as long as pedicellus, antennomere 3 thin and a little shorter than pedicellus, antennomeres 4 and 5 almost equal in length, slightly widening distally, club densely pubescent, with few long setae, compact, ca. 2.5× as long as wide.
Prothorax. Pronotum moderately convex, widest basally, arcuately narrowed in front, with punctures sparser than those on vertex, interstices between punctures smooth; posterior margin slightly arcuate. Prosternum strongly tectiform, with median carina and a distinct tooth anteromedially.
Meso- and metathorax. Scutellum longer than wide with rounded apex, in shape of isosceles triangle, with punctation similar to those on pronotum. Elytron moderately convex, sutural stria deeply impressed in posterior half; each elytron with 10 longitudinal serial punctures, deeply impressed in posterior half; intervals with fine ground punctures, each puncture with a K/H-shape microsculpture especially in posterior half of elytra (Fig. 53); series 3+4 and series 6+7 linked together subposteriorly, others serial punctures reaching end of elytron, lateral four series with punctures larger and deeper than the inner six series, around serial punctures with reticulation especially in posterior half. Mesoventrite with a Λ-shape divergent ridge at anteromedial portion, behind metaventral process (Fig. 57).
Legs. Reddish brown, rather short. Procoxae globular, pubescent; profemora without pubescence ventrally; protarsomeres without pubescence ventrally. Ventral surface of meso- and metafemora without pubescence, with sparse punctures and microsculpture; meso- and metatarsomeres with sparse pubescence ventrally, almost equal in length.
Abdomen. Pubescent, ventrite 1 with complete median carina, other ventrites uniformly convex, with complete marginal bead. Posteromedial portion of ventrite 5 wirhout pubescence, with mesh-like microsculpture, posterior margin of ventrite 5 rounded, with a stria in front of the marginal bead (Fig. 61).
Male genitalia (Fig. 25). Aedeagus about 1.15 mm long, ca. 2.4× as long as wide. Phallobase shorter than parameres, with short manubrium and rounded posteriorly. Parameres widest basally, gradually narrowing toward apex, outer margin slightly and continuously convex, incurved apically, inner margin almost truncate apically. Median lobe ca. 0.83× as long as parameres, widest in the basal 0.25, gradually narrowing towards apex; ventral plate of the median lobe triangular, widest basally, tapering towards apex, apex rounded, gonopore situated at apex of ventral plate (Fig. 25c), reaching almost apex of median lobe.
Biology. Unknown.
Distribution. China (Yunnan); Laos (Orchymont 1925). New for China.
The species of D. salvazai and closed species can be distinguished using following table.
description: Published as part of Mai, Zuqi, Hu, Jian, Minoshima, Yûsuke N., Jia, Fenglong & Fikáček, Martin, 2022, Review of Dactylosternum Wollaston, 1854 from China and Japan (Coleoptera, Hydrophilidae, Sphaeridiinae), pp. 269-300 in Zootaxa 5091 (2) on pages 294-296, DOI: 10.11646/zootaxa.5091.2.3, http://zenodo.org/record/5843837