Manestella tristriata (Mann)

Winterton, Shaun L. & Lambkin, Christine L., 2012, New Australian stiletto flies: revision of Manestella Metz and description of Medomega gen. n. (Diptera, Therevidae, Agapophytinae), ZooKeys 240, pp. 1-119 : 15-16

Manestella tristriata (Mann) Figs 5152535455

Psilocephala tristriata Mann, 1933: 331 - Irwin and Lyneborg 1989: 358 [catalogue].

Manestella tristriata (Mann) - Metz et al. 2003: 13.

Type material.

Holotype male, AUSTRALIA: Victoria: Kiata [-36.363, 141.790], Oct. 1928, F. E. Wilson (NMV).

‘Allotype’. AUSTRALIA: Victoria: female, Kiata [-36.363, 141.790], Oct. 1928, F. E. Wilson (NMV).

Other material examined.

AUSTRALIA: Victoria: 5 males, 5 females, Little Desert National Park, Western Block, Elliots track, 61.5km WSW Nhill [-36.536, 141.028], 19-22.xi.2002, C. Lambkin, D. Yeates, N. Starick, J. Recsei (ANIC).

Diagnosis.

Wing mottled infuscate; male frontal setae shorter than scape setae; frons protruding in profile; multiple irregular rows of postocular setae adjacent to ocellar tubercle in male; femora dark brown; male abdomen with dense silver velutum; gonocoxites without ventromedial projection, velutum patch distinct.

Redescription.

Body length= 3.0-4.0 mm (male), 4.0-5.0 mm (female). Head. Frontal pubescence silver-grey with dark brown markings, profile raised as rounded tubercle around antennal base, narrow brown medial stripe and dark spot above antennal base (male), or brown medial stripe, spot laterally and crescent above antennal base (female); male with patch of short dark setae within dark spot above antenna, shorter than setae on scape, female with scattered short setae, longer dorsally; male frons width at narrowest point narrower than anterior ocellus but not contiguous; male with multiple irregular rows of black postocular setae; occipital pubescence grey, narrow triangular marking medially; genal setae pale; antennal scape almost equal length to flagellum, numerous large dark setae, flagellum brown with silver pubescence laterally and medially. Thorax. Scutal pubescence grey with dark brown pattern, scattered dark setae, denser anteriorly, two dark medial stripes anteriorly, joining posteriorly, lateral stripes broken to tessellate; scutal macrosetae long and dark; pleuron with silver-grey pubescence; katatergite setae uniformly pale; anepisternum with grey-brown marking dorsally; coxae dark or pale, overlain with silver-grey pubescence, setae mostly pale; femora dark grey-brown, apices yellow, short dark setae, admixed with longer pale setae; tibiae yellow, dark grey-brown apically; tarsi dark yellow with apices brown; wing mottled infuscate; vein M3 complete to wing margin;scutal chaetotaxy (pairs): np, 3; sa, 1; pa, 1; dc, 6; sc, 1. Abdomen. Male abdomen base colour darkish, obscured by extensive silver velutum on tergites 2-7, vestiture mostly elongate pale setae, denser laterally; terminalia brown; female abdominal markings with tergites dark brown dorsally, intersegmental membrane distinctly pale, well defined. Male genitalia. Gonocoxite without medial process; outer gonocoxal process relatively short, truncated, narrow distally; gonocoxite velutum extensive, distinct with prominent medial tuft.

Comments.

Manestella tristriata is the type for the genus, and was originally described by Mann (1933) as a species of the broadly defined ‘dump’ -genus Psilocephala Zetterstedt. Metz et al. (2003) erected Manestella based on this species. This species is differentiated from all other Manestella species based on the mottled wing, protruding frons, frontal setae smaller than scape setae, and the distinctive tufted velutum patch on the ventral surface of the gonocoxite.