Neoclypeodytes balkei Scheers & Hájek 2020, sp. nov.
Creators: name: Scheers, Kevin
name: Hájek, Jiří
Publisher: name: Zenodo
Year: 2020
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Coleoptera
Dytiscidae
Neoclypeodytes
Neoclypeodytes balkei

description: Neoclypeodytes balkei sp. nov.
(Fig. 1)
Type material. Holotype: m#, “ Panama: Panama, Campana, / cascade below Anam office, / 270m, 19.vi.2007, / 08.40.818N 079.54.075W, / Balke (PAN 07) [p] // HOLOTYPE m# / NEOCLYPEODYTES / balkei sp. nov. / K. Scheers & J. Hájek det. 2020 [p, red label]” (ZSMG). Paratypes: 46 specimens; same label data as holotype (BMNH, CKSB, NMPC, ZSMG). Each paratype is provided with the appropriate red printed label.
Description of male holotype. Habitus (Fig. 1A). Ovoid-shaped, slightly attenuate anteriorly and strongly attenuate posteriorly; lateral outline nearly continuous between pronotum and elytra in dorsal aspect. Surface shiny.
Coloration. Head piceous. Antennae with antennomeres I–IV uniformly pale testaceous, antennomeres V–XI slightly infuscated apically. Palpi pale testaceous. Disc of pronotum piceous, medially slightly lightened; lateral parts of pronotum pale testaceous, broadly reaching inwards. Elytron dark piceous with two testaceous maculae; anterior (subbasal) macula subquadrangular, extending from lateral margin to one fifth of elytral width to suture, anterior margin straight with small emargination sublaterally, posterior margin largely concave with posteriorly protruding tooth near suture; posterior macula not reaching suture, anteriorly not reaching lateral margin, with concave emargination towards suture, posteriorly reaching lateral margin and apex of elytron (Fig. 1A); epipleuron completely testaceous. Legs including tarsi testaceous. Prosternum, mesepisterna and mesepimera rufotestaceous; metaventrite, metepisterna and metacoxae rufotestaceous, somewhat darkened at lateral portions. Abdominal ventrites piceous.
Head with fine but distinct microreticulation anterior of occipital line; punctation consisting of fine punctures near eyes and coarser punctures on clypeus; anterior clypeal margin medially distinctly flattened; occipital line narrowly separated from posterior margin of eyes.
Pronotum widest at base; lateral bead distinct; lateral margin evenly rounded; microreticulation absent; punctation consisting of punctures separated by 2–3× puncture diameter, punctation somewhat sparser laterally and distinctly denser near anterior and posterior margins; basal striae sinuated, distinctly curved inwards near base and slightly outwards anteriorly, length about 0.55× length of pronotum measured along same line as stria.
Elytra with basal striae straight, about same length than those on pronotum; sutural striae absent; microreticulation absent; punctation similar to that of pronotal disc, but with punctures slightly larger; epipleura sparsely punctate, with moderately oblique humeral carina; lateral epipleural rim anteriorly visible in dorsal view.
Legs. Pro- and mesotibiae club shaped. Pro- and mesotarsomeres 1–3 distinctly broadened, ventrally with adhesive setae. Metatarsomeres with well-developed natatorial setae on both sides.
Ventral surface (Fig. 1B). Prosternum medially narrowly convex, coarsely sculptured; prosternal process rather broad, subovate with apex broadly obtuse, laterally margined, slightly constricted medially. Metaventrite distinctly punctate over entire surface, punctures separated by 2–4× puncture diameter. Intralinear space of metacoxa broad (ML/MW = 2.40), sparsely and irregularly punctate with fine punctures, punctures separated by 1–4× puncture diameter; metacoxal plates distinctly punctate with coarse punctures, punctures separated by 1–3× puncture diameter, plates narrowly impunctate along anterior and posterior margins. Abdominal ventrite I coarsely punctate along margins, ventrite II sparsely and finely punctate; succeeding ventrites smooth with a row of setae bearing punctures along posterior margin and some sparse and fine punctures scattered over surface; ventrites IV and V with a tuft of long setae medially; ventrite VI unmodified.
Male genitalia. Median lobe in ventral view rather slender, parallel over whole length; apex distinctly truncate (Fig. 1C); ventral surface in apical part lacking scale-like setae (see under N. fortunensis sp. nov., and cf. Fig. 3D). Median lobe in lateral view broadest in apical third; ventral outline almost evenly curved; dorsal outline almost straight medially, distinctly curved inwards near apex (Fig. 1D). Lateral lobe (paramere) with apical segment elongated, nearly straight; in apical half on inner side with several long setae; apex distinctly curved but not protruding, subapical incision not perceptible (Fig. 1E).
Variability. With the exception of small variability in extent and shape of elytral color pattern, there is no significant variation present within the specimens of the type series.
Sexual dimorphism. The females have the dorsal surface completely reticulated with irregular polygonal meshes and thus they appear submatt; pro- and mesotarsomeres are less broadened than in males.
Measurements. TL: 2.05–2.15 mm (mean value: 2.10 ± 0.03 mm); holotype: 2.15 mm. TL-h: 1.85–1.95 mm (mean value: 1.85 ± 0.04 mm); holotype: 1.95 mm. TW: 1.10–1.20 mm (mean value: 1.15 ± 0.01 mm); holotype: 1.20 mm. Ratio TL/TW: 1.73–1.82 (mean value: 1.80 ± 0.02).
Differential diagnosis. Neoclypeodytes balkei sp. nov. is, together with N. curtulus and N. fortunensis sp. nov., one of only three representatives of the genus known south of Guatemala. The three species are easily distinguished from each other by the color pattern (cf. Figs 1A, 2 A–B and 3A), and the male genitalia with the median lobe parallel in ventral view, not medially expanded in lateral view (Figs 1 C–D) and lacking distinct scale-like setae at the apex (which are very distinct in both N. curtulus and N. fortunensis sp. nov.), and the apical part of the lateral lobe with appendage not protruding (Figs 1E, 2F and 3F).
The new species differs from the other species in the genus by the combination of the distinctive color pattern, the absence of sutural striae, the shape of the basal pronotal and elytral striae, and the male genitalia. In the identification key of Miller (2001), the new species falls into couplet 24, together with N. fryii (Clark, 1862) and N. quadrinotatus (Sharp, 1882); from both these species, N. balkei sp. nov. differs by the posteriorly strongly attenuated habitus, more strongly punctured metacoxal plates, and by the male genitalia (cf. Figs 1 C–E, and Figs 20C–E and 21C–E in Miller (2001)).
Etymology. The new species is named after Michael Balke, who collected the type series of this species. The specific epithet is a noun in the genitive case.
Collection circumstances. The specimens were collected in small water holes in the bedrock around a cascade of a forest stream (M. Balke, pers. comm. 2020) (Fig. 4). At this locality, the species was co-occurring with N. curtulus.
Distribution. To date the species is only known from the type locality at Campana, Panama province, Panama (Fig. 6).
description: Published as part of Scheers, Kevin & Hájek, Jiří, 2020, Neoclypeodytes Young from Panama, with description of two new species (Coleoptera: Dytiscidae: Hydroporinae: Bidessini), pp. 245-256 in Zootaxa 4890 (2) on pages 246-248, DOI: 10.11646/zootaxa.4890.2.5, http://zenodo.org/record/4301869