Mesembrinella semihyalina Mello, 1967

Whitworth, Terry L. & Yusseff-Vanegas, Sohath, 2019, A revision of the genera and species of the Neotropical family Mesembrinellidae (Diptera: Oestroidea), Zootaxa 4659 (1), pp. 1-146 : 131-132

Mesembrinella semihyalina Mello, 1967

( Figs 87–88, 177–178, 231, 274, 318, 362, 403, 447, 488)

Mesembrinella semihyalina Mello, 1967: 73 . Holotype male (FIOC), not examined. Type locality: Parque Sooretama , Espirito Santo, Brazil.

Mesembrinella semihyalina: Toma & Carvalho (1995: 138) ; Kosmann et al. (2013: 78); Wolff (2013: 121); Marinho et al. (2017: tab. 1); Cerretti et al. (2017: tab. 2).

Diagnosis. A medium-sized fly averaging 12.2 mm (11–13/5) in length. Wing infuscated; supravibrissal setae brown; subcostal sclerite setose; wing with section IV 0.23 of section III; male phallus in dorsal view with weak serrations ( Fig. 178); legs entirely orange. Male frons about 0.06 of head width at narrowest; epandrium, cerci and surstyli as in Figs. 87–88. Female T6 of WU shape ( Fig. 318).

Redescription. Male. Head. Frons 0.063 (0.06–0.07/3) of head width at narrowest. Fronto-orbital and parafacial pale silvery when viewed from above, pale orange when viewed from below; frontal setae ascending halfway to vertex; frontal vitta dark orange, obliterated midway; gena pale orange with horizontal row of few dark setae anteriorly, otherwise with small dark setae; postgena pale yellow with fine yellow setae; occiput with pale yellow tomentum and yellow setae; median occipital sclerite shiny black; antenna orange, first flagellomere with pale tomentum, arista dark orange; palpus typical; eye with median facets 3x size of lateral facets; ocellar triangle medium-sized, anterior ocellus 2x size of posterior ocelli; short row of tan supravibrissal setae on facial ridge ascending, about 1/6 of distance to antennal base.

Thorax. Dorsum with alternating dark brown areas with yellowish tomentose stripes; pleura dark orange with whitish tomentum; spiracles small, pale orange; chaetotaxy: ac variable, 2:1or 2:2, sometimes one or more setae missing, dc 2:3, ia 1, ph 1, ppn 3x 3, kat 1:1, meral setae typical, 1 pair of parallel ap, sa and lat absent, 1 bas, 1 weak pb, 1 disc; subscutellum moderately developed; spiracles medium-sized, pale yellow; legs entirely orange. Wing faintly infuscated along distal 2/3 of costa through R 2+3 and along veins; basicosta and tegula pale orange; section IV 0.23 of section III; upper calypter with pale disc and dark rim with reddish setae; lower calypter with pale disc and rim, rim with long pale setae.

Abdomen. T1+2 dark orange; T3–T5 shiny blue with patchy white tomentum; rear margins of T4–5 with stout setae; disc of T5 with dense, medium-long, fine setae only. Terminalia in lateral view with surstylus broad, with gradual backward curve, cercus with apical hook ( Fig. 87); in posterior view, base of cerci broad, relatively short and stout, narrowing apically to chisel-like tip ( Fig. 88); phallus in lateral view with epiphallus short and stout with slight backward curve ( Fig. 177); in dorsal view, hypophallic lobes slightly rounded with shallow, moderate serrations ( Fig. 178). T6, STS7+8, pre- and postgonite, ejaculatory sclerite and ST6 as in Fig. 231; ST2–5 as in Fig. 274.

Female. Similar to male except frons 0.248 (0.23–0.26/5) of head width at narrowest. T6 of WU shape; T7 continuous; T8 narrowed midway; epiproct divided midway ( Fig. 318); ST6–8 and hypoproct as in Fig. 362; spermathecae filiform ( Fig. 403); ST1–5 as in Fig. 447.

Type material examined. PARATYPE: Brazil, Distrito Federal. 1 ³, Parque Sooretama (Cupido), E. Santo, L. Travis, H. Travis, II/III-948 ( CNC) .

Additional material examined. Brazil, Alagoas. 1 ♀ ♦ ( TLW392 ) , Murici , 26–30.vii.2012, S.S. Nihei, P.G. Dias, D.M. Alcantara, C.S. Costa ( NHMUK) ; 1 ³♦, same data except ( TLW392 ) ( NHMUK) . São Paulo. 1 ³*, 11.ii.1923, L.G. Saunders ( NHMUK) . Rio de Janeiro. 1 ³*, Angra dos Reis, E. de Rio ( CNC) ; 1 ♀, Angra do Reis , 29.v.1972, H.S. Lopes ( CNC) . Rondônia. 1 ♀ *, 3 ♀♀, Caucalândia, 10°32ʹS 62°48ʹW, 21.x.1991, 1 ♀ ♦ ( TLW432 ) , J. McDonald ( MEM) ; 1 ♀ *, 62 km, SW Ariquemes nr Fzda. Rancho Grande , 6–15.xii.1990, D.A. Rider, J.E. Eger ( FSCA) .

Distribution. Brazil.

Remarks. Bonatto (2001) argued that this species is a synonym of M. abaca [here considered a synonym of M. socors ], but M. semihyalina has a distinct, dark infuscation in cells r 1 and r 2+3, while M. socors has, at most, a faint yellowing in the r 1 cell along the costa. The known range of M. semihyalina is Brazil, whereas M. socors is known only from Central America. Two specimens of M. semihyalina ( TLW 392 and TLW 432) were barcoded; they clustered together, close to M. anomala and distant from M. socors (genetic distance 12%) ( Fig. 488), supporting the morphological differentiation between these two species.