Dineutus barong, Gustafson & Hájek & Miller, 2016

Gustafson, Grey T., Hájek, Jiří & Miller, Kelly B., 2016, Description of two new species of Dineutus sensu stricto from Southeast Asia (Coleoptera: Gyrinidae) with a key to the known species of the subgenus, Acta Entomologica Musei Nationalis Pragae 56 (2), pp. 629-643 : 633-636

Dineutus barong sp. nov.

(Figs 4, 11, 20, 23–24, 26–27)

Type material. HOLOTYPE: J (card mounted; aedeagus in microvial), ‘INDONESIA. BALI / Bedugul Distr. , 1200 m / Tamblingan lakes / Local collectors, vii 2004 ’ [white label, typed, black ink] // ‘ HOLOTYPE / Dineutus barong sp. nov. / Gustafson, Hájek & Miller, 2015’ [red label, typed, black ink] (deposited in NMPC) . PARATYPES (27 specimens): INDONESIA: BALI: same label data as holotype (9 spec. NMPC, 1 spec. MSBA) ; ‘ INDONESIA, BALI: Buleleng Distr. / Munduk - Air Terjun Melanting / stream + hygropetric below waterfall / 08°15.5’S, 115°04.2’E ; 940 m / 21.ii.2015 ’ [white label, typed, black ink] (13 spec. NMPC) ; ‘ Indonesia: Bali, Telaga forest , / BLI007’ [white label, typed, black ink] (2 spec. ZSMG) ; ‘ Indonesia / Bali / BA 8 / 3km NE of Candi Kuning / Waldbach, 1320 m, 11.7.1991 / leg: Balke & Hendrich’ [white label, typed, black ink] (1 spec. LHCM) ; Indonesia / Bali / 5 km nördl. Bedugul / 27.& 28.8.1990, 1300m /BA 4&5 / leg: Balke & Hendrich [white label, typed, black ink] (1 spec. LHCM) ; ‘ INDONESIA, BALI: Buleleng Distr. / ca. 9 km SW Singaraja / 8°11ʹ34.3ʺS, 115°03ʹ59.2ʺE, 465 m / N. Suprayitno leg., 29.ix.2016 ’ [white label, typed, black ink] (26 spec. MZBC, NMPC, NSUB, ZSMG). All paratypes provided with additional label ‘ PARATYPE / Dineutus barong sp. nov. / Gustafson, Hájek & Miller, 2015’ [red label, typed, black ink].

Diagnosis. Body form (Fig. 4) elongate oval, males laterally slightly expanded just posterior to midlength, in lateral view dorsoventrally strongly convex, greatest convexity just posterior to scutellar region; antenna with six antennomeres; elytral apices with apicolateral sinuation present (Fig. 11), apex broadly rounded, preapical sericeous patch of reticulation absent, lateral marginal depression narrow; male protarsus ( Fig. 23 ) narrow. Aedeagus ( Fig. 20 ): median lobe parallel sided for 3/4 its length, strongly acuminate in apical fourth with rounded lateral margins, apex with tip narrowly rounded, in lateral view apex slightly constricted, weakly dorsally curved. Female reproductive tract ( Fig. 24 ): spermatheca relatively elongate and broad, gonocoxae with lateral margins appreciably straight, apex nearly obliquely truncate.

Description of male holotype. Habitus. Larger member of genus; body form elongate oval, weakly attenuated anteriorly, widest point just posterior to midlength of elytra (Fig. 4); in lateral view greatest convexity just posterior to scutellar region, strongly convex relative to other species in Dineutus s. str.

Coloration. Dorsally head, pronotum, elytra olive-green, venter reddish brown, elytral epipleuron, middle- and posterior legs, and abdomen lighter.

Head. Dorsally, vertex with reticulation mostly effaced; frons with reticulation composed of very small ovoid sculpticells, with sparse and shallow punctation, almost imperceptible medially – mostly effaced by uniform reticulation, laterally punctation more impressed, separated by ca. 4–5× diameter of a puncture, some shallow wrinkles present paramedially, apicolateral corners of frons wrinkled, frontoclypeal suture with posterior margin weakly arched, lateral margins obtusely angled, almost arcuate; clypeus shallowly emarginate anteriorly, nearly truncate in dorsal view, with faint wrinkles laterally, strong reticulation compose of round sculpticells, effaced at extreme anterior margins, with sparse punctation, punctures appear shallow in reticulation – more impressed at anterior margin where reticulation imperceptible; labrum with dense punctation marginally, punctures well-impressed, separated by ca. 1.0–1.5× diameter of a puncture, punctation absent basomedially in small circular area, replaced by faint reticulation, composed of elongate ovoid sculpticells; ultimate palpomere of labial palps with asymmetrical anterior and posterior margins, anterior margin weakly curved, nearly straight, posterior margin evenly curved towards broadly rounded apex.

Thorax. Pronotum with strong regular reticulation laterally, composed of round sculpticells, these slightly larger and more regularly rounded laterally, medially reticulation much less impressed, composed of smaller, round sculpticells; punctation evenly distributed, punctures shallowly impressed, nearly imperceptible laterally except upon close examination, medially punctures separated by ca. 4–5× diameter of a puncture; pronotal transverse line well-impressed and nearly complete, medially weakened and irregular, but still traceable; lateral marginal depression of pronotum narrow, widest anteriorly, attenuated posteriorly; posterior margin of pronotum fairly strongly sinuate. Profemora with two sub-apicoventral teeth, one on anteroventral margin, one on posteroventral margin; teeth relatively small and similar in size; protibial distolateral margin broadly rounded, indistinct; protarsus relatively narrow, with lateral margins weakly rounded, ultimate protarsomere slightly less than 2× longer than wide; protarsomeres on ventral side with numerous thin adhesive setae terminated with round sucker cups; mesotarsal claws with anterior claw narrow, sharply curved, with ventral margin nearly straight, weakly narrowing in apical third ( Fig. 23 ). Elytra completely cover scutellar shield, lateral marginal depression narrow in basal third, interrupted by swelling created by ventral depression where fore legs received, then broadened to nearly twice width in apical 2/3; sericeous preapical patch of reticulation completely absent; punctation present, nearly imperceptible laterally due to strong reticulation, double punctation evident in scutellar area, where reticulation barely perceptible: dense micropunctures between sculpticells ca. 1/3× size of larger punctures, and larger punctures of approximately size of sculpticells separated by ca. 3–4× diameter of a puncture; reticulation composed of round sculpticells; all elytral striae faintly evident; apicolateral sinuation present; elytral apices narrowly rounded.

Genitalia. Aedeagus ( Fig. 20 ) with median lobe shorter than parameres, parallel sided for 3/4 its length, strongly acuminate in apical fourth with rounded lateral margins, apex with tip narrowly rounded; in lateral view tip of median lobe slightly constricted, weakly dorsally curved, dorsally apical half with short spine-like setae; parameres weakly laterally expanded in apical third, apex flatly rounded.

Variability. Sexual dimorphism. Male broader and more attenuated anteriorly, female much more regularly oval in body form. Female protarsomeres not expanded, on ventral side without adhesive setae; female profemora without sub-apicoventral teeth. Female reproductive tract ( Fig. 24 ) with lateral margins of gonocoxae weakly expanded, apex somewhat obliquely truncate; laterotergites apically weakly laterally expanded, spermatheca relatively elongate and curved to left after fertilization duct.

Measurements. Male: length = 15.5–20.0 mm (holotype = 17.0 mm), width = 9.5–12.0 mm (holotype = 10.5 mm). Female: length = 15.5–18.0 mm width = 9.5–11.0 mm.

Differential diagnosis. Dineutus barong sp. nov. is most similar to D. politus in having the elytra with an apicolateral sinuation (cf. Figs 10 and 11) and absence of a preapical sericeous reticulation patch. However, it can be distinguished from that species by the much more regularly elongate oval body form (cf. Figs 1 and 4) and increased dorsoventral convexity. The aedeagus will unambiguously separate the two species, as D. barong sp. nov. has a longer and more acuminate apex of the median lobe (cf. Figs 19–20 ).

Collection circumstances. The specimens from Tamblingan were collected in the inflow of a temporary stream to the lake; in Munduk, the specimens were observed in a partly shaded stream, ca. 2 m wide, below the waterfall ( Figs 26–27 ).

Etymology. This species is named after Barong, the benevolent Balinese lion-like king of the spirits; it is a noun in the nominative case, standing in apposition.

Distribution. This new species is currently only known from a mountainous area in northern Bali.

Figures

Figs 15– 23.15–21 lateral and dorsal view of the aedeagus of Dineutus s. str.species.15 – D. fulgidus Régimbart, 1880; 16 – D. regimbarti Régimbart, 1882; 17 – D. mellyi Régimbart, 1882; 18 – D. brownei Mouchamps, 1949; 19 – D. politus W. S. Macleay, 1825; 20 – D. barong sp. nov.; 21 – D. sitesi sp. nov. Scale bars = 1 mm. 22–23 male protarsus and mesotarsal claw: 22 – D. sitesi sp. nov.; 23 – D. barong sp. nov. Scale bars of protarsus = 1 mm, mesotarsal claw scale bars = 0.5 mm.

Figs 24–25. Female reproductive tract of new Dineutus s. str. species. 24 – D. barong sp. nov.; 25 – D. sitesi sp. nov. Scale bars = 1 mm.

Figs 26–27. Habitat of D. barong sp. nov. 26 – Jan Šumpich in general habitat; 27 – D. barong sp. nov. in habitat, individuals demarcated by circles.