Morellia (M.) insularis Pont, 2006

Pamplona, Denise, Nihei, Silvio S., Couri, Márcia S. & Pont, Adrian C., 2016, Taxonomy of Morellia Robineau-Desvoidy (Diptera: Muscidae): revision of the subgenera Morellia s. str. and Parapyrellia Townsend, Zootaxa 4163 (1), pp. 1-110 : 47-48

19. Morellia (M.) insularis Pont, 2006

(figs 1–2 in Pont 2006)

Morellia insularis Pont, 2006: 38 . Type locality: SEYCHELLES, Praslin, G'Anse. Holotype Ƌ, BMNH (seen).

Redescription (based on the original description). Colour. Ground-colour black. Fronto-orbital plate silvery-white pruinose on lower third, brownish above this and subshining at vertex; parafacial silvery-white, gena and lower occiput light grey; antenna black; palpus dark brown; thoracic spiracles dark brown; mesonotum with light grey dust, tinged with yellow behind, as follows: a median vitta beginning at neck and occupying the acrostichal space, narrowed slightly behind suture, broadening before scutellum to cover the prescutellar dorsocentral setae; a broad patch over postpronotal lobe and notopleuron; a small postsutural vitta between intra-alar and supra-alar setae; mesonotum thus appearing to have two broad black vittae from neck to scutellum; pleura thinly light grey dusted; scutellum in posterior view undusted except on ventral edge from base almost to apex and on a pair of lateral patches between sub-basal lateral and subapical discal setae; legs black; wing brownish costally and basally, otherwise without markings, veins yellow; basicosta and tegula dark brown; lower calypter brownish, with white margin and fringe, upper calypter white; haltere yellow; abdominal tergites covered with rather dense grey dust, without any shifting chequered patches, in dorsal and posterior views with the following areas black and undusted: all of syntergite 1+2; a median vitta and a hind-marginal band on tergites 3–5, these both narrow on tergite 5; sides of tergites 3–5 dusted, except on hind-margins, and sternites 2–5 dusted except around edges.

Male. Body length: 4.5–6.0 mm; wing length: 4.0– 5.5 mm.

Head. Frons at narrowest point slightly broader than diameter of anterior ocellus; eye virtually bare, with only the usual microscopic pubescence; upper inner facets enlarged as usual but not strikingly so; fronto-orbital plate very narrow, at lunule a plate not quite half width of postpedicel; frontal vitta linear, visible on half of frons only as a seam where the fronto-orbital plates touch; 12–15 pairs of moderate frontal setae, extending from lunule to anterior ocellus, those on upper two-thirds proclinate, only those on lower third inclinate; orbitals absent; postpedicel 2.5 times as long as broad; arista long-plumose, the longest combined plumosity equal to length of postpedicel; parafacial slender, at middle not quite half width of postpedicel, hardly narrowed below; vibrissal angle below level of profrons; setulae on facial ridges ascending half the distance from vibrissa to base of postpedicel; gena moderate, the depth below lowest eye-margin equal to width of postpedicel; peristomal setae short but quite dense; beard black; proboscis not elongated, prementum thinly dusted; palpus slim.

Thorax. Ground-setulae quite short and dense on mesonotum; acrostichals 0+1; dorsocentrals 2+5, the presutural and anterior two postsutural pairs short and fine; 1 postsutural intra-alar; prealar short, less than half length of 2nd notopleural seta; prosternum and proepisternal depression bare; anepisternum with fine setulae upcurved on upper-anterior corner; notopleuron with only a few setulae at the base of the setae, these sometimes absent; katepisternals 1+2; katepimeron usually with 1–3 setulae, rarely bare; meron haired below spiracle and on metakatepisternum, rarely bare; posterior spiracle with a few setae on posterior margin; katatergite and anatergite bare; scutellum setulose all over disc and lateral margins, and at ventral angle of lateral margins with fine setulose hairs, with strong sub-basal lateral, subapical discal and apical setae. Legs: without striking modifications; fore femur without anteroventral setae, with a complete posteroventral row; fore tibia in apical half with erect setulae on posterior to posteroventral surfaces, and 3–4 posteroventral setae; mid femur normal in shape, without preapical notches or tubercles, anteroventral surface with several short setae in basal two-fifths, and posteroventral surface with a row of moderate setae from base to just beyond middle, a strong anterior seta at middle, 0 anterior and 3 posterodorsal to posterior preapical setae; mid tibia without basal notches or tubercles, and without erect anterior setulae, without setae except for 4–5 posterior setae; hind femur with a few short posteroventral setae in basal third, with a complete anteroventral row, the setae short in basal half; hind tibia with a strong calcar, without further setae on this surface, anterodorsal surface with a row of short setae, 2–3 of them stronger, without posteroventrals, 3–4 short anteroventral setae, dorsal apical seta present and longer than tibial depth, an anterodorsal and a posterodorsal apical also present, shorter than the dorsal. Wing membrane entirely covered with microtrichia, without any bare patches; stem-vein with a few short setulae in basal part, before humeral cross-vein, on upper and lower surfaces, those on upper surface sometimes absent; vein R1 bare; vein R4+5 with a few setulae at base on upper and lower surfaces, not extending as far as cross-vein r-m; cell r4+5 at wing tip slightly shorter than cross-vein r-m.

Abdomen. Tergites without any striking setae; sternite 1 setulose.

Terminalia. See illustrations of sternite 5 and cercal plate in Pont (2006: figs 1–2).

Female. Body length: 4.0– 5.5 mm; wing length: 3.5–5.0 mm.

Similar to male but differing as follows: frons broad but at middle much less than an eye-width; frons parallelsided, only broadening just before lunule; fronto-orbital plate subshining black on upper two-thirds, silvery-white pruinose on lower third; parafacial, gena and lower occiput also silvery-white pruinose; frontal vitta matt black, frontal triangle subshining and reaching halfway from anterior ocellus to lunule; inner vertical seta long and strong, outer vertical hardly distint from the adjacent post-ocular setulae; fronto-orbital plate broadening slightly from vertex to lunule, and frontal vitta consequently narrowing; at middle, fronto-orbital plate one-third width of frontal vitta; 9–10 pairs of inclinate frontal setae, with a few interstitials; 2 pairs of short reclinate and 2 pairs of welldeveloped proclinate orbital setae; fronto-orbital plates with only a few setulae outside the setae; frontal vitta bare; parafacial slightly broader; the median dusted mesonotal vitta very constricted behind suture, actually or almost separated from the prescutellar patch; presutural and anterior postsutural dorsocentrals shorter and finer; fore tibia without any posterior or posteroventral setae; mid femur with the anteroventral and posteroventral setae shorter, the posteroventrals virtually absent; hind tibia with the anterodorsal row setulose, with 1–2 setae; vein R4+5 with the setulae usually reaching to cross-vein r-m but at most only 1 setula beyond this point; lower calypter yellowish, sometimes rather dirty outside; dusting on abdomen yellowish-grey, with some shifting chequered patches on tergites 4 and 5.

Material examined. SEYCHELLES: Praslin, G’Anse, 30.v.1906, P.R. Dupont, holotype Ƌ ( BMNH) . Same data as holotype, paratypes 4 ♀♀ ( BMNH) ; Praslin , 29.v.1906, P.R. Dupont col., 1 Ƌ ( BMNH) ; Mah , 11.xi.1977, David & Tsacas col., 1 Ƌ ( MNHN) ; Mah , La Mare aux Cochons, 7.xi.1977, David & Tsacas col., 2 ƋƋ ( MNHN) .

Distribution. AFROTROPICAL: Seychelles Islands.