Metatrichia dhimurru, Winterton, Shaun L. & Woodley, Norman E., 2009

Winterton, Shaun L. & Woodley, Norman E., 2009, New species of Metatrichia Coquillett (Diptera: Scenopinidae) from Australia and Venezuela, Zootaxa 2094, pp. 42-51 : 43-44

Metatrichia dhimurru sp. nov.

urn:lsid:zoobank.org:act:EA45BFF4-5B5F-4807-B06A-0230039C0BA7 ( Figs. 1–3 , 8 A–B)

Type material. Holotype male, AUSTRALIA: Northern Territory: Arnhem Land [Gove Peninsula], 12º 25.779’S, 136º 49.616’E; S.L. Winterton; 18.viii.2007; 14m amsl; monsoon forest in sand dunes ( ANIC).

Diagnosis. Body uniform black colour, covered with white scale-like setae; legs black; wing hyaline; abdomen without ivory-white patches on tergites 5–8; gonostylus crescent-shaped.

Description. Body length 3.5 mm. Head. Glossy black; frons covered with silver-white setae; frons slightly protruding anteriorly, almost contiguous dorsally, face black, parafacia narrow, glabrous; mouthparts well developed, brown; antenna black-brown, overlain with silvery pubescence, admixed with short dark setae on scape and pedicel; ocellar tubercle slightly raised, overlain with silvery pubescence; postocular ridge very narrow, without macrosetae; occiput relatively flat with minute setae laterally; gena covered with short dark and pale setae. Thorax. Glossy black, scutum densely overlain with silver-white setae, setae scale-like anteriorly and laterally; small pale ridges on postpronotal and pteropleural calli; pleuron densely overlain with silver-white setae on anepisternum and katepisternum, setae scale-like on anepisternum; legs black with pale setae on coxae and femora; haltere brown with pale area ventrally; wing hyaline, venation brown. Abdomen. Black, slightly dorso-ventrally flattened; covered with black pubescence dorsally; densely overlain with white setae laterally and ventrally, admixed laterally with white, scale like-setae; postero-medial margins of tergites 6–7 slightly pale. Male genitalia ( Figs. 8 A–B). Epandrium band-like, with posteriorly directed margins ventrally, halves not completely covering gonocoxites ventrally, sclerotised along medial margins; cerci flaplike and directed ventrally over hypoproct; gonocoxite with medially directed triangular process along ventral surface; gonocoxal apodeme relatively narrow in lateral view; gonostylus crescent-shaped with setae along medial margin; hypandrium in two halves, posteriorly directed knob-like process medially; distiphallus short, broad with briefly narrowed apex, bifurcating arms of distiphallus divergent in ventral view; ventral apodeme of parameral sheath deflexed ventrally; ejaculatory apodeme large, spatulate.

Comments. Metatrichia dhimurru is known from a single male specimen collected in monsoon forest nestled between sand dunes on the Gove Peninsula, Northern Territory ( Australia). This species is very closely related to M. waterhousei based on male genitalia characters such as distiphallus and gonostylus shape, but clearly differs externally by the absence of ivory patches on the abdomen. Metatrichia dhimurru differs from M. papuana by the presence of scale-like setae on the head and thorax and hyaline wings; scalelike setae are absent and wings darker in the latter species ( Kelsey 1970).

Etymology. The specific epithet is named after the Dhimurru people of Arnhem Land (Northern Territory).

Figures

FIGURE 1. Metatrichia dhimurru sp. nov., male, Arnhem Land, Northern Territory (Body length = 3.5 mm) (Photo: S. L. Winterton).

FIGURE 2. Metatrichia dhimurru sp. nov.: Holotype male, dorsal. Body length = 3.5 mm.

FIGURE 3. Metatrichia dhimurru sp. nov.: Holotype male, lateral. Body length = 3.5 mm.

FIGURE 8. Metatrichia dhimurru sp. nov.: A, male genitalia, dorsal view; B, same, lateral view. Metatrichia venezuelensis sp. nov.: C. male genitalia, dorsal view; D, same, lateral view. Abbreviations: c, cercus; d, distiphallus; e, epandrium; ea, ejaculatory apodeme; ga, gonocoxal apodeme; gs, gonostylus; gx, gonocoxite; hy, hypandrium; va, ventral apodeme. Scale lines: 0.2 mm.