Mesembrinella batesi Aldrich, 1922

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 : 112-113

Mesembrinella batesi Aldrich, 1922

( Figs 5, 57–58, 103, 147–148, 216, 259, 303, 347, 388, 432, 471, 488, 490)

Mesembrinella batesi Aldrich, 1922: 15 . Holotype female (NHMUK), examined. Type locality: Brazil, R. Amazons [= Amazon River ].

Mesembrinella batesi: Peris & Mariluis (1984: 260) ; Toma & Carvalho (1995: 137); Kosmann et al. (2013: 78); Wolff (2013: 121); Marinho et al. (2017: tab. 1); Cerretti et al. (2017: tab. 2).

Diagnosis. A large dark fly averaging 12 mm (11–13/5) in length. Postpronotal lobe 3x 3, stem vein bare; wing with strong infuscation along anterior margin between costa and R 4+5; subcostal sclerite with long, dark setae; abdomen with heavy white tomentum and dark, pit-like areas around setal bases ( Fig. 103).

Redescription. Male. Head. Frons narrow, 0.017 (0.01–0.02/5) of head width at narrowest, about equal to width of base of arista; fronto-orbital broad below, very slender above, frontal setae ascending about 30% of distance to vertex; frontal vitta as an orange triangle in lower 1/3, obliterated above; parafacial bright silvery, narrow above, broad below; gena orange with short, tan setae and a horizontal row of stout setae extending across gena and lower parafacial to vibrissa; pale tomentum extending from occiput into posterodorsal corner of gena; postgena with silvery tomentum with long golden setae; occiput with heavy yellow tomentum and with long, weak pale yellow setae; median occipital sclerite shiny, dark orange; pedicel and first flagellomere yellow-orange; palpus typical; ocellar triangle small, anterior ocellus slightly larger than posterior ocelli; eye with median facets about 2x size of lateral facets; facial ridge with short row of dark brown supravibrissal setae ascending about 1/6 of distance to antennal base.

Thorax. Dorsum orange-brown with four broad irregular pale tomentose stripes, pleural area orange; chaetotaxy: ac variable, usually 2:3 but sometimes 2:1 or 2:2, dc 2:3, ia 1, ph 1, ppn 3x 3, kat 1:1, 1 pair converging ap, 1 weak sa, 1 weak lat, 1 stout bas, 1 weak pb, 1 disc; subscutellum moderately developed; spiracles medium-sized, pale yellow. Legs yellow-orange; mid and hind tibiae and tarsi tan. Wing with strong macula along anterior edge between costa and R 4+5; subcostal sclerite with long dark cilia ( Fig. 490); basicosta dark orange; tegula pale orange; section IV 0.36 of section III; calypters with tan discs; upper calypter with dark rim and short pale setae, lower calypter with pale rim and long, pale setae.

Abdomen. T1+2–5 more or less shiny blue and covered with heavy whitish tomentum, with dark pit-like areas around setal sockets ( Fig. 103); T3 with two pairs of lateral marginal setae, T4 with weak row of setae on posterior margin; disc of T5 with dense, fine setae only. Terminalia in left lateral view with surstylus curved backward, cercus nearly straight with apical hook ( Fig. 57); in posterior view, cerci with narrow base, of rectangular shape with blunt, rounded tips ( Fig. 58); phallus in lateral view with epiphallus with broad base and tip sharply curved backward to a fine point ( Fig. 147); in dorsal view, hypophallic lobes broad and elongate, oval-shaped ( Fig. 148); T6, STS7+8, pre- and postgonite, ejaculatory sclerite, ST6 and hypandrium as in Fig. 216; ST1–5 as in Fig. 259, ST3–4 unusually narrow.

Female. Similar to male except frons 0.302 (0.29–0.31/5) of head width at narrowest. T6 of WV shape; T7 broad, continuous with anterior edge, recessed midway; T8 as separate sclerites ( Figs 303); ST6–8 and hypoproct as in Fig. 347; spermathecae filiform ( Fig. 388); ST1–5 as in Fig. 432.

Type material examined. HOLOTYPE ♀ ( Brazil; NHMUK; Fig. 471), labeled: Brazil: / R. Amazons. / H.W. Bates. / 66.53.; Amazon. / 66 53; Mesembrinella / batesi / Type Ald.

Additional material examined. Brazil, Rondônia. 1 ³, 2 ♀♀, 62 km SE Ariquemes , 22–31.x.1997, W.J. Han- son ( LACM) ; ♀ *, same data except 13–25.iv.1992 ( LACM) ; 2 ♀♀, same data except 8–20.xi.1994 ( LACM) ; 1 ³, 1 ♀ *, 1 ♀, 62 km SE Ariquemes, nr. Fzda. Rancho Grande , 6–15.xii.1990, D.A. Rider & J.E. Eger ( FSCA) ; 1 ♀ *, 1 ♀ ♦ ( TLW424 ) , 4 ♀♀, same data except 4–16.XI.1997, Fish Carrion Pitfall, J.E. Eger ( LACM) ; 1 ³♦ ( TLW421 ) , 1 ♀, same data except 3–15.xii.1996, MV & black lights, J.E. Eger ( LACM) ; 1 ♀, 160–350 m vic. Caucalandia , 10°32ʹS 62°48ʹW, 12–13.x.1991, pitfall trap baited with human feces, J.R. MacDonald ( MEM) . Ecuador, Napo. 1 ³♦ ( TLW228 ) , 1 ³, 1 ♀ ♦ ( TLW231 ) , 1 ♀, Misahualli nr. Tena , 6–19.x.2001, Mal. Tr., C. Brammer ( LACM) ; 1 ³*, 1 ³♦ ( TLW227 ) , 1 ♀ ♦ ( TLW229 ) , same data except 27.iv–2.v.2003 ( LACM) ; 1 ³, same data except Yasuni Res. Sta. , 0°40.566ʹS 076°23.851ʹW, 250 m, M.T. ( LACM) . Orellana. 1 ♀ ♦ ( TLW230 ) , RioTiputini , 0°38.2ʹS 76°8.9ʹW, 12–26.viii.1999, W.N. Mathis, A. Baptista, M. Kotrba ( LACM) . Pastaza. 1 ³, Limoncocha, 70 mi. SE, on Rio Cononaco, at Anglo air strip, 1°19ʹS– 76°6ʹW, 29.v.1976, Malaise trap, J. Cohen ( LACM) . Peru, Cusco. 1 ³, 2 ♀♀, Pilocapata, Villa Carmen Biológica Sta. , 12°53ʹS 71°24ʹW, i–iii.2013, E. Rodriguez ( FSCA) ; 1 ♀ ♦ ( TLW422 ) , same data except v.2014, multilure trap, M. Choque ( FSCA) ; 1 ³*, Estación Biológica Villa Carmen , clearing edge, 12°53ʹ39ʺS 71°24ʹ14ʺW, xi.2012, T. Forster ( USNM) ; 1 ♀ ♦ ( TLW423 ) , same data except 12.xii.2013, bait trap, dead fish, A.L. Norbom, B.D. Sutton ( FSCA) . Loreto. 1 ♀, 80 km NE Iquitos, Explorama Lodge, 11 km from Amazon R. on Rio Yanamono , 1–5.ix.1992, human dung trap, Castner & Skelley ( FSCA) ; 1 ³*, La Merced, Fundo Genova , 30.vii.2008, [no collector] ( CEUA) .

Distribution. Brazil, Ecuador, Peru. Marinho et al. (2017) also listed it from Colombia, Venezuela and Trinidad and Tobago.

Remarks. Eight specimens were barcoded, from Ecuador ( TLW 227–230), Peru ( TLW 422–423) and Brazil ( TLW 421 and TLW 424). An additional GenBank sequence from Brazil ( KR820711 ) was added to the analysis. All sequences clustered together, with some genetic variation likely based on geographical separation. The genetic distance between sequences from within Ecuador was less than 2%, whereas between sequences from Peru and Ecuador it was around 6% and between sequences from Brazil and Ecuador it was around 5% ( Fig. 488). This is a distinctive species and no significant morphological differences were found in specimens from different countries.