Male. Body length 6.9–8.0 mm. Ratio frons width/head width at vertex level 0.34–0.35.

Coloration (Fig. 4–5): Fronto-orbital plate and parafacial deeply golden. Occiput black with white pruinosity; most occipital setulae white. Frons brownish and broad. Scape dark brown and without pruinosity; first flagellomere dark brown with white pruinosity; arista brown. Palpus yellow, covered by dark setulae; proboscis dark brown. Gena with golden pruinosity. Thorax dark-brown colored, nearly black, with four distinct stripes and white pruinosity. Scutellum dark brown, nearly black, but brown on apex, with white pruinosity. Wing hyaline; calypters white; haltere yellow. Legs dark-brown, nearly black, with white pruinosity on fore coxa ventrally. Abdomen blackish, T1+2 with white pruinosity, more conspicuous on ventral side, T3 with white pruinosity, T5 with strong golden pruinosity and brown apex. Head (Fig. 5–7): Eyes slightly haired. Seven frontal setae, three of which inserted below the level of antennal insertion. Frons width about 1/7 of the head width. Two reclinate fronto-orbital setae at the upper portion. Fronto-orbital plate densely covered by delicate fine setulae mostly on upper half. Ocellar setae proclinate and as strong as reclinate fronto-orbital setae. Several fine and long postocellar setulae, no developed seta. Inner vertical setae strong, slightly convergent and reclinate; the outer vertical setae weak, divergent, less than half the length of the inner. First flagellomere elongated, about 5× its width, almost reaching the lower facial margin. Arista bare, about the same length as antenna, and narrowing abruptly on the upper half. Parafacial bare. Facial ridge with setulae from vibrissa almost until the level of insertion of arista. Vibrissae long and cruciate. Gena about 1/6 of the eye height. Thorax: Acrostichals 3+3; dorsocentrals 3+4; supraalars 1+3, the first postsutural one strong (stronger than the first post-dorsocentral seta); intra-alars 2+3, the first presutural seta beside the postpronotal lobe and the second presutural seta very close to the suture. One developed seta between the first presutural intra-alar and first presutural supra-alar. Intra-postalar seta present. Postpronotals 4. Notopleurals 2. Prosternum setulose. Proepisternum bare. Katepisternals 2+2, the lower ones weaker. Posterior spiracle rounded and covered by a flap-shaped tuft of setulae. Scutellum with one pair of basal and subapical setae longer and stronger than lateral and discal pair of setae, and one apical cruciate pair, the latter longer than discal but shorter than lateral pair. Wings: Cell R4+5 open, the distance between apex of R4+5 and M as long as r-m crossvein. Base of R4+5 setulose dorsally and ventrally; remaining veins bare. Legs: Tarsal claws as long as or slightly longer than last tarsomere. Fore femur with posterodorsal and posteroventral rows of setae, the posterior face welldeveloped setae forming an irregular row; fore tibia with anterodorsal row of setae on the mid third, two strong posterior setae on the mid third; tarsal pulvilli as long as the claws. Mid femur with weak anteroventral row of setae and strong posteroventral row, about 3–4 strong median setae on anterior face, and three preapical oblique posterodorsal setae; mid tibia with one strong median anterodorsal seta, one submedian ventral seta, and two posterior setae on the mid third. Hind femur with anterodorsal and anteroventral rows of setae, a posteroventral row of setae, with long setae on the basal half, and two preapical oblique posterodorsal setae; hind tibia with an anterodorsal row of setae of subequal size, but one long submedian seta, 3–4 anteroventral setae, the basal ones weaker, and two posterodorsal setae on the mid third. Abdomen: T1+2 excavated until the posterior margin, with a pair of lateral marginal setae; T3 with a pair of median marginal setae and two pairs of lateral marginal setae; T4 with a row of marginal setae reaching the ventral margin; T5 with a row of marginal setae, with irregular discal setae, and covered by setulae more separated from each other than on previous tergites. Male terminalia (Fig. 8–11): Sternite 5 as in Fig. 8. Cerci slightly broadened at base, tapering toward the apex in posterior view (Fig. 9), the tip elongated and narrow and slightly curved inwards, ending beyond the apex of surstyli. Surstyli, in lateral view (Fig. 10), broad and the apex round but the middle narrow; in posterior view (Fig. 9) with a median projection on the inner surface. Pregonite (Fig. 11) narrowing towards the apex and covered by few cilia; postgonite connected to hypandrium. Epiphallus slightly broadened at base, but uniformly narrowed until the apex. Distiphallus composed by a broad dorsal sclerite, with an elongated and narrow membrane (Fig. 11).

Female. Body length 6.9–7.0 mm. Ratio frons/head width at the vertex level: 0.36–0.38. Differs from male as follows: two proclinate fronto-orbital setae; five frontal setae, three of which are below the insertion of antenna; aristas slightly broader; palpus orangish and conspicuously broadened, with dark setulae restricted to base; tarsal claws shorter than last tarsomere.

Third instar (Fig. 12–13). Length 9.0 mm. General color whitish gray; cephalopharyngeal skeleton (Fig. 12) characterized by a conspicuous mandible and hypopharynx; tentorial phragma heavily sclerotized; dorsal and ventral cornus expanded, less sclerotized. Posterior spiracles (Fig. 13) heavily sclerotized with four very sinuous openings, two of which are shorter and adjacent to the others which are separated by thin prolongations of the wall of the spiracle.

Type material examined. Holotype male, BRAZIL, Rio de Janeiro, Nova Friburgo (22° 17′S-42°29′W), 29.vi-02.vii.2002, H. R. Gil-Santana leg.(MZSP). Paratypes: same data, 2 males and 3 females (MZSP), 1 male and 2 females (MNRJ), with same data, also two third instars.

Etymology. The new species is named in homage to Dr. Rubens Pinto de Mello for his great contributions to the study and teaching of entomology in Brazil, particularly those on Diptera.

Remarks. Lespesia melloi sp. nov. resembles L. lata (Wiedemann, 1830) and L. lanei Guimarães, 1983 by its fronto-orbital plate and parafacial strongly golden pruinose, but differs from the former by the bare eyes and two lateral scutellar setae (eyes densely setulose and three lateral scutellars in L. lata). Nevertheless, the new species is morphologically very similar to L. lanei, and it runs to couplet 5 of the key provided by Guimarães (1982: 12) along with L. lanei. And when compared with the type-series of L. lanei deposited at the MZSP, L. melloi sp. nov. can be distinguished by the following features: