Discodon tenuecostatum Biffi & Geiser 2022, sp. nov.

Discodon tenuecostatum sp. nov.

urn:lsid:zoobank.org:act: 7DC62ADA-E43F-4874-AB7D-97EED692DB78

Figs 5D, 6H, S, 7H, 8H, 9H, 10H, 12J–M, 15H

Similar to D. obscurior and D. nigrocephalum by the general coloration. It differs especially by the weakly defined elytral costulae (Fig. 5D) visible under unidirectional lighting, the shape of the pronotum

(Figs 7H, 8H), which is less arched anteriorly, the tarsal claws of the males (Fig. 9H), ventrite VII of the males (Fig. 10H) and females (Fig. 15H) and the aedeagus (Fig. 12J–M).

The name tenuecostatum refers to the weakly defined longitudinal elytral costulae in both males and females.

Holotype BRAZIL • ♂; Rio de Janeiro, Teresópolis, Parque Nacional da Serra dos Órgãos; 4–9 Nov. 2013; V.S. Ferreira and F.F. Barbosa leg.; MZSP 46459 (Fig. 5D).

Paratypes (11 specimens) BRAZIL • 3 ♂♂, 1 ♀; same collection data as for holotype; MZSP 46460, 46461, 46463, 46466 • 1 ♀; same collection data as for holotype; UFMG-ICO-2200001 • 1 ♀; same collection data as for holotype; DZUP 320984 • 1 ♀; same collection data as for holotype; CEMT CUIABA 00118357 • 1 ♂, 1 ♀; same collection data as for preceding, Casa do Pesquisador; 16 Dec. 2016; Simeão Moraes leg.; MZSP 46467, 46468 • 1 ♀; [Parque Nacional do] Itatiaia; Nov. 1966; Dirings col.; MZSP 46469 • 1 ♀; Rio de Janeiro, Serra do Macaé; Nov. 1909; E. Garbe leg. [15,235]; MZSP 45594.

Body length: 11.7–16.2 mm. Coloration (Fig. 5D): head pitch black, lustrous, except in lateral corners and anterior margin of clypeus, dark brown; mandibles dark brown, darker at base and tip; maxillary and labial palpi dark brown, light brown in last palpomeres; antennae black at base, clearing apicad, antennomeres I–II black, III–V dark brown, VI–XI light brown, sometimes III–V light brown and the latter orangish. Pronotum (Figs 7H, 8H) lustrous, partly translucent, with broad irregular black band from anterior to posterior margin, wider anteriorly and near posterior margin, and narrower near anterior half; background pale yellow with diffuse orange regions. Scutellum and elytra entirely pitch black, slightly lustrous. Thorax, legs and abdomen black, tarsal claws brown.

Male

Head short, as long as wide, excluding eyes; integument smooth, densely covered with short and fine clear setae; frons short, vertex flat, occipital region convex, broadly rounded behind eyes. Clypeus flat, anterior margin emarginate, slightly projected anteriorly with rounded median incision. Eyes small, rounded, prominent. Mandibles falciform, acute, without accessory teeth. Last maxillary and labial palpomeres securiform. Antennae (Fig. 6H) long, reaching elytral apical third, slightly flattened dorsoventrally; antennomeres narrowing proximally, sub-serrate, without longitudinal lines. Pronotum (Fig. 7H) wide, about 1.5 times as wide as long; anterior margin slightly arched, anterior angles arched; lateral margins sinuate, almost parallel anteriorly, and widened before lateral deep notch at posterior third; integument smooth, densely covered with very fine yellow setae. Elytra very long, each elytron 5.6 times as long as wide, almost parallel; integument coriaceous, densely covered with short and fine decumbent setae, and much longer thick erect setae. Legs slender, densely pubescent, covered with long and thick setae; tarsi flattened dorsoventrally, fourth tarsomere with transversal slit at base; anterior prothoracic tarsal claws (Fig. 9H) broadly lobed basally, lobe with very broad rounded margin; posterior claws on meso- and metathoracic tarsal claws apparently split at apex, with fine protruding tooth slightly shorter than claws. Abdomen weakly sclerotised, coriaceous, densely covered with long setae; ventrite VI with posterior margin concave; ventrite VII (Fig. 10H) with triangular concave lobes, inner margins nearly parallel, directed ventrally, outer margins convergent posteriorly, apical margins rounded, with tip directed internally. Aedeagus (Fig. 12J–M) very robust, ventral wall of tegmen elongate, lateral margins constricted apically; apex forming a pair lobes with rounded projections, with strongly sinuous aspect; broad central projection, strongly flattened laterally with flat plaque-like projection ventrally, usually visible between ventrite lobes; fringe of long setae along lateral margins of tegmen dorsally; parameres very short, hidden between tegmen and median lobe; median lobe membranous, with strong falciform sclerites directed dorsally and central tufts of thick pubescence.

Female

Similar to male; antennae (Fig. 6S) shorter; pronotum (Fig. 8H) wider, 1.7 times as wide as long, subrectangular, anterior margin nearly straight, lateral margins without notch; tarsal claws without basal lobe or apical slit; ventrite VI not notched, distal margin slightly arched, concave; ventrite VII (Fig. 15H) long and broad, lateral and distal margins broadly arched, apex with two long and broad apical lobes projecting posteriorly at middle and U-shaped medial notch.

Brazil (Rio de Janeiro state) (Fig. 16).