Mesembrinella violacea Whitworth, 2019

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 : 96

Mesembrinella violacea Whitworth , sp. nov.

( Figs 51–52, 141–142, 213, 256, 299, 343, 428, 468, 488)

Diagnosis. A large blue-black fly, averaging 11.75 mm (11–13/4) in length. Postpronotal setae 2x 2; subcostal sclerite bare; outer ph absent; wing faintly yellowish, darker yellow near base of costa; abdomen blue-black; male frons narrow, 0.015 of head width at narrowest.

Description. Male. Head. Frons narrow, 0.015/3 of head width at narrowest, about half width of parafacial at level of lunule; fronto-orbital pale and slender, frontal setae ascending about 30% of distance to vertex; frontal vitta obliterated in upper 2/3, lower third of frontal vitta orange, of triangular shape; parafacial narrow, silvery when viewed from above, orange when viewed from below; gena pale orange with mix of long and short black setae, posteroventral corner with silvery tomentum and black setae extending from occiput; postgena orange with long orange setae; occiput mostly covered with silvery tomentum and fine, short golden setae; median occipital sclerite shiny dark reddish-brown; upper edge just below postoccipital setae without tomentum, shiny black with short black setae; antenna orange; palpus typical; eye with median facets about 3x size of lateral facets; ocellar triangle small, anterior ocellus about 1/3 larger than posterior ocelli; facial ridge with only small cluster of supravibrissal setae at base of facial ridge.

Thorax. Dorsum shiny orange-brown with three broad, irregular tomentose stripes extending from prescutum through to scutum; pleural area orange; chaetotaxy: ac 1:1, dc 2:3, ia 0, ph 0, ppn 2x 2, kat 2:1, meral setae typical, 1 pair crossed ap, sa absent, 1 weak lat, 1 stout bas, pb absent, 1 disc; subscutellum weakly developed; spiracles medium-sized, anterior spiracle pale yellow, posterior spiracle orange; legs: femora orange, tibiae and tarsi brown. Wing faintly yellowish, slightly darker yellow near base of costa; basicosta pale orange, tegula brown; section IV 0.13 of section III; discs of calypters reddish-brown; rim of upper calypter dark with short, dark reddish setae; rim of lower calypter pale with long, pale reddish setae.

Abdomen. T1+2 orange-brown; T3–5 dark shiny purple with whitish tomentum in anterior half; T1+2 with lateral cluster of long setae and lone marginal seta posterolaterally; T3 with pair of posterolateral setae; T4 and T5 each with row of stout marginal setae; disc of T5 with horizontal row of stout setae midway, rest of disc with dense, fine setae. Terminalia in lateral view with surstylus fairly broad and parallel sided, with slight backward bend distally, cercus with apical hook ( Fig. 51); in posterior view, base of cerci narrow, parallel-sided, rectangular and with pointed tips ( Fig. 52); phallus in lateral view with medium-sized epiphallus and large basiphallus ( Fig. 141); in dorsal view, hypophallic lobes narrow with coarse serrations ( Fig. 142); T6, STS7+8, pre- and postgonite, ejaculatory sclerite, ST6 and hypandrium as in Fig. 213; ST2–5 as in Fig. 256.

Female. Similar to male except frons 0.223 (0.21–0.24/3) of head width at narrowest. T6 of RV shape; T7 broad and continuous, weakened midway; T8 wide, weakened midway; epiproct divided ( Fig. 299); ST6–8 and hypoproct as in Fig. 343; ST2–5 as in Fig. 428.

Type material. HOLOTYPE ³* ( Costa Rica , Limon; INBIO; Fig. 468), labeled: Est. Hitoy Cerere, 100 m, / R. Cerere. Res. Biol. Hitoy / Cerere, Prov. Limon, / Costa Rica, 30 jul a 20 jun / 1992, F.A. Quesada / L-N 184200, 643300; COSTA RICA INBIO / CRI000 / 769913 ; HOLOTYPE / Huascaromusca / violacea / T.L. Whitworth.

ALLOTYPE ♀ ♦ ( TLW410 ): Costa Rica, Limón. Matina , 2.5 km sw de Colonia Puriscalefia 300 m, 15 Oct 1999, E. Rojas L_N_221700 604300 #56990 ( INBIO).

PARATYPES: Costa Rica, Alajuela. 1 ³♦* ( TLW265 ) , P.N. Volcau Teuorio Est. Pilou, 1.5 km s. C. Carmela , 700–800 m, 15.ix–9.x.2006, J.A. Azofiefa, Malaise Trap ( INBIO) . Cartago. 1 ♀ ♦ ( TLW332 ) , Turrialba Tres Equis, P.N. Barbilla Send Prinicipal a R. Barbilla, 400–500 m, 20–21.i.2002 ( INBIO) ; 1 ³♦ ( TLW400 ) , Chirripo, Turri- alba, Grano de Oro , 1120 m, 31.viii.1992, P. Campos ( INBIO) . Limón. 1 ♀ *, Est. Hitoy Cerere, R. Cere Res. Biol. Hitoy Cerere , Costa Rica, 100 m, vi.1992, L_N_184200 643300, G. Carballo ( INBIO) .

Distribution. Costa Rica.

Remarks. Four specimens ( TLW 265, TLW 332, TLW 400 and TLW 410) were barcoded. They formed a distinct group close to M. nigrocoerulea sp. nov. ( Fig. 488).

Etymology. The species name violacea is derived from the Latin violaceus (purple) and was chosen because of the distinctive dark purple abdomen in well-preserved specimens.