Neurigona lopesi sp. nov.

(Figs 1–3, 6–12)

Description. Male (Fig. 1). Body length: 3.3–3.5 mm. Wing length: 3.1–3.2 mm. Head. Frons dark green with thin white pruinosity, approx. 1/4 head width, slightly converging anteriad; eyes separated on face, narrowest distance in middle of face 0.5 times distance between ocellar setae; face and clypeus with dense silver pruinosity; palpus yellow, covered by 9–10 dark setulae, with 2 strong setae on apex; proboscis yellow, with short whitish hairs and pair of long white hairs posteriad; pair of proclinate, divergent, strong ocellar setae, almost twice longer than verticals; pair of proclinate, slightly convergent vertical setae, 2/3 length of ocellars; pair of tiny postocellar setae; pair of reclinate paravertical setae, slightly longer than verticals; postocular setae pale, in single row, with 1–2 upper setae black, dorsalmost several times longer than others; occiput metallic dark green, with thin white pruinosity. Antenna yellow; pedicel with crown of apical setae; postpedicel trapezoidal, as long as wide; stylus about 6 times as long as postpedicel, dorsally inserted with short pubescence.

Thorax. Dorsum of mesonotum ochreous-yellow, with narrow median brownish stripe between acrostichals, mesonotal depression dark brown with greenish reflections; scutellum dark brown with yellowish hind margin, remaining pleura, including notopleuron light yellow, except little dark spot below wing insertion. Acrostichal setae biserial, extending to mesonotal depression; each side of mesonotum covered by short scattered setae on anterior 1/3; 6 pairs of dorsocentral setae, decreasing in size anteriad (first and second pairs sometimes indistinct from setal background); 1 presutural (sometimes indistinct, 0.1 times as long as sutural), 1 post- and 1 sutural intra-alar seta; 1 pre- and 1 postsutural supra-alar seta; 1 strong postalar seta; 2 notopleural setae, 1 strong postpronotal seta and 2 tiny hairs; lower surface of proepsternum with 1 strong white seta and 1 dark setula above; upper surface of proepisternun in front of anterior spiracle bare; scutellum with pair of strong median setae and pair of tiny hairs laterad. Wing. Membrane hyaline. Costal vein ending at wing apex; R 1 ending before mid-length of wing; R 2+3 straight, ending at apical fifth of wing; R 4+5 slightly curved backwards; apical half of distal part of M 1 slightly bent anteriorly; CuA+CuP strong, not reaching wing margin. RMx ratio = 0.77, CuAx ratio = 0.38. Lower calypter and cilia yellowish; stem of halter yellow, knob brownish yellow. Legs. Entirely yellow. Pulvilli and claws present on all legs. Femora with short vestiture and bare of major setae. Tarsi without conspicuously long setae. Leg I. Podomere ratios: 13, 10.5, 9, 5, 2.5, 1.5, 1. Anterior surface of coxa I covered by sparse, short black setae, distal edge with 2–3 strong whitish setae, and 1 black seta laterad. Tibia I without conspicuous setae. Leg II. Podomere ratios: 12.5, 16.5, 13, 5, 3, 2, 1. Anterior surface of coxa II covered by short vestiture of black setae, apical edge with 2 pale setae. Tibia with anterior to anterodorsal setae at basal 1/4 and near basal 3/4; with 1 small posterodorsal seta at base, 1 short dorsal seta at basal 3/4 and 2 apical setae. Leg III. Podomere ratios: 10, 15.3, 4, 5.3, 2.7, 2, 1. Coxa III with strong, black lateral seta in basal half, with 1–2 tiny hairs above. Tibia III with 1 small, black dorsal seta at base, 1 longer, pale dorsal seta near middle, 1 anterodorsal black seta at basal 1/4 and apical ring of 3 black setae.

Abdomen. Mostly dark yellow, sternites 1–5 paler, tergites 2–5 with anterior dark brown bands laterally. Setae on tergites black, those on hind margin of segments 1–5 longer. Tergite 5 brown, covered by fine white setae with yellow hind margin; sternite 5 brown, with strong triangular ventral projection. Tergite 6 brown and bare. Tergite 7 brown, sternite 7 yellowish, bare. Sternite 8 brown. Hypopygium (Figs 2, 6–12). Genital capsule dark brown, surstyli dark brown to black, their apices paler (Figs 2, 6). Ventral lobe of surstylus (Fig. 7) with pointed projection bearing long and medially curved seta, with shorter seta at base of projection. Dorsal lobe of surstylus (Fig. 8) with rounded, slightly translucent apex and short rugose projection directed inwards. Apicoventral epandrial lobe (Fig. 9) four-branched, with one branch unsclerotized, delicate, arborescent-like with several tiny hairs. Basolateral epandrial lobe (Fig. 10) simple, digitiform. Hypandrium (Fig. 11) with distal part simple, without projections. Postgonite (Fig. 11) with pointed apex. Cercus (Fig. 12) with dark, sclerotized lateral part; medial part delicate, with digitiform projection bearing modified seta.

Female. Body length: 3.9 mm. Wing length: 3.1 mm. Very similar to male, except as noted: narrowest distance in middle of face equal to distance between ocellar setae; face with dense silver pruinosity, clypeus yellow; knob of halter yellow. Abdomen. Tergite 1 yellow, ground colour of tergites 2–5 yellow, but with anterodorsal brown patches on each side, becoming larger towards segment 5. Sternites 1–4 yellow, sternite 5 brownish. Ovipositor (Fig. 3). Retracted within segment 5, acanthophorites and cerci generally visible and directed downwards. Acanthophorites elongate, with long, delicate setae and without spines, as commonly seen in Neurigona (Bickel 1998) .

Type material. HOLOTYPE ♂, labelled: “ Brazil, GO [Brazilian State of Goiás], Niquelândia | RPDS [Reserva Particular de Desenvolvimento Sustentável] Legado Verdes do Cerrado | Malaise 6— Cerrado [savanna] s.s. 3 | 14°36′46.65′′S 48°29′54.33′′O [W] | 21.x.2019 – 19.xi.2019 | Cols. Oliveira, R. S. & Lopes, W. R.”, “ HOLOTYPE | Neurigona lopesi | Silva, Capellari & Oliveira [red label]” (MZSP) . Holotype in good condition, genitalia not dissected (MZSP) . PARATYPES: 1♂, same data as the holotype (MZSP); 1♂, same data except, Malaise 2— Mata de Galeria [riparian forest] 2 | 14°36′43.71′′S 48°28′49.93′′O (UFG) .

Additional material. BRAZIL. 1♂, GO, Mineiros, Parque Nacional [National Park] de Emas, Malaise trap, 17°54′25.2′′S 52°59′03.0′′W, 12.x.–11.xi.2018, Cols. Oliveira & Lopes (UFG) ; 3♂, 1♀, Tocantins, Palmas, Parque Estadual [State Park] do Lajeado, Igarapé [waterway] da Onça, Malaise trap. 03°56′30.9″S, 54°52′30.43″W, 18.i.2018, G. Amora & J.O. Silva leg ; 1♂, same data except, 19.xii.2017 (INPA) .

Etymology. Named after the Brazilian dipterist, Welinton Ribamar Lopes (UFG), who collected the type series of this species.

Remarks. The new species is very similar to N. orbicularis, as both share one distinct yellowish seta at middle of tibia III and have a pointed ventral lobe of the surstylus (Fig. 7). They can be differentiated by details of the genital capsule, mostly the shape of the dorsal lobe of the surstylus, which has a short rugose projection in N. lopesi sp. nov.

Distribution. Brazil (States of Goiás and Tocantins, Cerrado biome).