Mesembrinella decrepita Séguy, 1925

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 : 79

Mesembrinella decrepita Séguy, 1925

( Figs 39–40, 129–130, 207, 250, 293, 337, 379, 422, 488)

Mesembrinella decrepita Séguy, 1925: 195 . Holotype male (MNHN), not examined. Type locality: Colombia.

Huascaromusca decrepita: Peris & Mariluis (1984: 255) ; Kosmann et al. (2013: 77); Wolff & Kosmann (2016: 867); Marinho et al. (2017: tab. 1); Velásquez et al. (2017: 108).

Mesembrinella decrepita: Cerretti et al. (2017 : tab. 2).

Diagnosis. A medium-sized blue-black fly averaging 9.6 mm (9–10/5) in length. Postpronotal lobe with 3x 3 setae; subcostal sclerite bare; femora pale orange. Male frons about 0.074 of head width at narrowest; terminalia distinctive, with broad cerci in posterior view ( Fig. 39). Female T6 distinctive, with broad division midway and of OV shape; T7 and T8 narrowed midway ( Fig. 293).

Redescription. Male. Frons broad, 0.074 (0.07–0.08/5) of head width at narrowest, almost as broad as width of first flagellomere; fronto-orbital dark with silvery tomentum; frontal setae ascending about 60% of distance to vertex; frontal vitta: upper 2/3 black, lower 1/3 orange; parafacial orange with pale tomentum; gena orange with horizontal row of stout dark setae and scattered smaller dark setae; postgena orange with long pale setae; occiput dark with pale tomentum and pale setae; median occipital sclerite shiny black; antenna orange; arista tan; palpus typical; eye with median facets slightly larger than lateral facets; ocellar triangle medium-sized, anterior ocellus about 2x size of posterior ocelli; supravibrissal setae on facial ridge ascending about 1/5 of distance to antennal base.

Thorax. Dorsum and pleural areas blue-black with whitish tomentum; chaetotaxy: ac variable, most commonly 1:1, then 2:1, then 0:1, sometimes a seta missing on one side, dc 2:3, ia 0, ph 1, ppn 3x 3, kat 2:1, meral setae typical, 1 pair crossed ap, 0 sa or lat, 1 stout bas, 1 weak pb, 1 disc; subscutellum moderately developed; spiracles orange, mediumsized. Wing hyaline, with section IV 0.17 of section III; subcostal sclerite bare; basicosta and tegula orange; calypters brown with brown rims; rim of upper calypter with short dark setae, rim of lower calypter with long pale setae.

Abdomen. T1+2–T3 shiny blue with whitish tomentum, T4–5 shiny blue with little tomentum; T1+2–3 with pair of lateral marginal setae; T4–5 each with row of marginal setae, the row on T5 weaker; disc of T5 with middorsal horizontal row of stout setae, rest of disc with sparse, fine setae. Terminalia. In lateral view surstylus slender, curving slightly forward, cercus with apical hook ( Fig. 39); in posterior view, base of cerci broad, tapering to divergent tips ( Fig. 40); phallus in lateral view with epiphallus curved backward, basiphallus extended anteroventrally ( Fig. 129); in dorsal view, hypophallic lobes very narrow ( Fig. 130); T6, STS7+8, pre- and postgonite, ejaculatory sclerite and ST6 as in Fig. 207; sternites as in Fig. 250.

Female. Similar to male except frons 0.245 (0.23–0.25/4) of head width at narrowest. T6 of RV shape, broadly divided midway, T7 continuous, weakened and translucent midway, T8 broad with suture midway ( Fig. 293). ST6–8 and hypoproct as in Fig. 337; spermathecae filiform ( Fig. 379); ST1–5 as in Fig. 422.

Material examined. Venezuela, Distrito Federal. 1 ³*, 1 ♀ ♦* ( TLW378 ) , 7 ³³, Parque Nac. Avila , 1800 m, 28.ii.1971, G. & M. Wood ( CNC) . Lara. 1 ³♦ ( TLW258 ) , 1 ♀ ♦ ( TLW257 ) , 8 km. S Sanare, Yacambu Natl. Park 1600 m, 27.xii.1985, P. Kovarik & R. Jones ( TAMU) . Merida. 1 ³*, 10 km E. Tobay, 2000 m, 28.iv.1981, H. Townes ( CNC) . Yaracuy. 1 ³, Corceorote Sector El Candelo , 1650 m, 10°36ʹ888ʺN–68°82ʹ628ʺW, 17–20.x.2001, T. Interceptacion, R. Briceño, A. Chacán, J. Clavijo, F. Díaz, R. Paz, E. Arcaya & L. Joly ( MJMO) ; 1 ³♦ ( TLW259 ) , 1 ♀, Edo. Lara, P.N. Yacambu , “El Blanquito”, 9°63N, 69°53W, 29.i.2007, A. Martínez ( MJMO) .

Distribution. Venezuela. Bonatto (2001) also listed it from Colombia. The listing of this species from Mexico in Marinho et al. (2017: tab. 1) was an error (M. Marinho, pers. comm.).

Remarks. The only specimens examined during this study were from Venezuela. Four specimens ( TLW 252– 259, TLW 378) were barcoded, and they clustered together ( Fig. 488).