Oxysarcodexia ariozanoi sp. n.

(Figs 29–32)

urn:lsid:zoobank.org:act: 7A2C3145-C04F-45F5-B8D3-7B6F9E7DE09F

Diagnosis. Postocular plate with golden pollinosity. Ocellar bristles smaller than upper frontal bristles. Thorax grayish with golden pollinosity. Three well-differentiated post-sutural dorsocentral bristles; apical scutellar bristles present. Legs dark brown. Abdomen with silvery pollinosity. T1+2 with 1 pair of lateral marginal bristles, T3 with 2 pairs of lateral marginal bristles and T4 with 4 pairs of lateral marginal and 1 pair of median marginal bristles. ST5 with deep median cleft with margins almost parallel. Cercus with a median expansion in lateral view and square, slightly curved apex. Cerci parallel in posterior view. Pregonite broader than postgonite, with slightly curved, rounded apex; unicolorous. Postgonite slender, with slightly curved, square apex; unicolorous. Distiphallus with obliquely cut apex, lateral, dorsal and ventral projections, smooth margins and wide ventroapical opening. Vesica well sclerotized, emerging pre-apically from phallic tube as a short branch that folds ventroposteriorly, culminating in flattened elongate lobes with microscopic membranous cuticular spines on dorsal surface.

Description. Male. Length 7.7 mm.

Head. Fronto-orbital, parafacial and postocular plates with golden pollinosity; occiput blackish with golden pollinosity, black bristles in dorsomedial and lateral areas and a few golden bristles in mediomedial area; frons 0.1x head width at level of ocellar triangle; frontal vitta blackish, with row of 14 frontal bristles; inner vertical bristle well developed, outer vertical bristle 0.3x as long as inner one; ocellar bristles 0.8x as long as uppermost frontals; reclinate fronto-orbital bristles 2.2x as long as uppermost frontal, proclinate bristles absent; gena and postgena blackish with golden pollinosity and black bristles; antenna dark brown, first flagellomere with pale golden pollinosity and 2.3x as long as pedicel; arista brown and long plumose on proximal 2/3; palpus dark brown.

Thorax. Grayish with golden pollinosity. Chaetotaxy: acrostichals 3+1, dorsocentrals 3 (first weaker) + 3, intraalars 2+2, supra-alars 2+3, postalars 2, postpronotals 3, notopleurals 4 (2 large primaries and 2 smaller subprimaries), katepisternals 3 with middle one weaker and inserted slightly below others, meropleurals 8–9, postalar wall setose, scutellum with 1 basal, 1 discal, 1 lateral, 1 subapical and 1 apical, and bristle; prosternum with few bristles along margins. Wing. Hyaline, tegula black, vein R 1 bare, vein R 4+5 setulose over 3/4 of distance to crossvein r-m, costal spine not differentiated, third costal sector without ventral setulae. Legs. Dark brown, fore femur with 2 rows of bristles on posterodorsal and 1 on posteroventral surface; fore tibia with 3 dorsal, 1 posterodorsal, 2 posteroventral and 1 posterior bristles; mid femur with 6 median anterodorsal bristles, 2 pre-apical posterior bristles, anteroventral and posteroventral rows of bristles and a ctenidium of flattened spines on distal posteroventral surface; mid tibia with 1 dorsal, 2 posterodorsal, 1 posterior, 1 posteroventral, 1 ventral, 1 anterior and 2 anterodorsal bristles; hind femur with 1 posterodorsal and 1 dorsal bristle, anteroventral and anterodorsal rows of long bristles and apical posteroventral and anterior rows of bristles; hind tibia with 2 anteroventral, 3 anterodorsal, 2 dorsal, 1 anterior and 2 posterodorsal bristles; fore and hind tarsi with weak ventral golden pollinosity.

Abdomen. Grayish with silvery pollinosity. T1+2 with 1 pair of lateral marginal bristles, T3 with 2 pairs of lateral marginal bristles, T4 with 4 pairs of lateral marginal and 1 pair of median marginal bristles, T5 with 20 strong marginal bristles. ST2–4 oblong with scattered setulae along posterolateral and posterior margins, ST5 with deep median cleft with margins almost parallel. Terminalia . Syntergosternite 7+8 dark brownish with golden pollinosity, scattered black setulae and 8 marginal bristles; epandrium dark brownish with golden pollinosity, short black setulae and 2 strong bristles dorsoapically; surstylus oblong, elongate dorsoventrally, with sparse marginal and black discal setulae. Cercus with a median expansion in lateral view and square, slightly curved apex; cerci parallel in posterior view. Pregonite broader than postgonite, with slightly curved, rounded apex; unicolorous. Postgonite slender, with slightly curved square apex; unicolorous. Distiphallus with obliquely cut apex, lateral, dorsal and ventral projections, smooth margins and wide ventroapical opening. Vesica well sclerotized, emerging pre-apically from phallic tube as a short branch that folds ventroposteriorly, culminating in flattened elongate lobes with microscopic membranous cuticular spines on dorsal surface.

Female. Unknown.

Etymology. The specific epithet is given in honor of Ariozano de Souza, father of the first author.

Remarks. The “ Xarcophaga group” was proposed informally by Lopes (1975c) for species with an enlarged apex of the distiphallus, i.e., a distal enlargement of the juxta. Dufek & Mulieri (2017) also pointed out that species in this group share a more elongate cercus compared to other Oxysarcodexia, a typically narrow cercal prong, a more elongate phallus, and juxta folded backwards posteriorly, which excludes O. nitida . The group is therefore composed by O. berthet, O. catica, O. favorabilis, O. fraterna, O. ibera, O. liliarum, O. mineirensis, O. nitida, O. notata, O. pallisteri, O. peruviana, O. vittata and O. xon (Figs 52, 64, 112, 126, 143, 164, 180, 196, 199, 208, 226, 279, 288) (Lopes 1975c; Soares & Mello-Patiu 2010; Souza & Paseto 2015; Souza & Buenaventura 2016; Dufek & Mulieri 2017), to which we here add O. ariozanoi sp. n. (Fig. 30) and O. maiae sp. n. (Fig. 167). We denote the group as “ xon group”, in reference to the type species of Xarcophaga and in agreement with Dufek & Mulieri (2017). A flower-like (e.g., Fig. 112) or inflorescence-like (e.g., Fig. 164) juxta is shared by O. ariozanoi sp. n., O. favorabilis, O. liliarum, O. maiae sp. n. and O. mineirensis .

Distribution. NEOTROPICAL. Brazil (Rio de Janeiro).

Biology. Unknown.

Type material. Holotype ♂: BRAZIL: RJ Tijuca Forest nr Rio; 7–30.ix.1993, T.Pape / NRM-DIPT 0014641 [MNRJ].