Sigaloethina, Munari, 2004

Munari, L., 2004, Beach Flies (Diptera: Tethinidae: Tethininae) From Australia and Papua New Guinea, with Descriptions of Two New Genera and Ten New Species, Records of the Australian Museum 56 (1), pp. 29-56 : 46-47

Sigaloethina n.gen.

Type species. Sigaloethina phaia n.sp. ( Fig. 23).

Diagnosis. Dark flies having fairly to noticeably glossy cuticle; head higher than long; face depressed and partially membranous; lower face, above vibrissal angle, without tubercle (like Dasyrhicnoessa ); cephalic chaetotaxy typical of subfamily (though with setulae of frons and vittae a little impoverished in numbers); frons without discernible shining patch on both sides of ocellar triangle; arista of postpedicel bearing spaced, long hairs; eye densely micropubescent, very large, its longest diameter over 8× as long as genal height. Thorax entirely dark brown, glossy, slightly convex dorsally, with chaetotaxy typical of subfamily; disc of scutellum bare; thoracic cuticle covered with more or less faint grey microtomentum. Legs evenly setulose except for foreleg having coxa and femur with long setae; ctenidium of fore femur vestigial or even absent; mid femur of male with row of posteroventral, spine-like setae on entire length of femur; all legs with femora dark brown, remaining parts yellow to yellowish brown. Wing like those in Dasyrhicnoessa species , that is with vein R 2+3 slightly bisinuate; halter yellowish. Abdomen shining, black, with narrow, apicomarginal, pale brownish stripe on each tergite; tergites bearing several black setae and setulae. Male terminalia with lobe-shaped anterior surstylus ( Fig. 24) noticeably larger than posterior surstylus, latter straight and relatively narrow; anterior surstylus bearing characteristic triangular patch of microtrichia on outer surface; both surstyli bearing several tubercles on inner sides ( Fig. 25); cerci small; distiphallus ( Fig. 26) fairly complex, bearing membranous lobe medially; postabdomen of female with two spherical, smooth spermathecae.

Remarks. Sigaloethina is closely related to Dasyrhicnoessa differing from it particularly in having the body cuticle noticeably glossy, the frons lacking a discernible shining patch on both sides of the ocellar triangle, the setal vestiture of the frons slightly, even though distinctly, sparce, and for the peculiar morphology of the male terminalia. On the basis of the present knowledge, Sigaloethina might be regarded as the sister group of Dasyrhicnoessa .

Etymology. The generic epithet derives from the fusion of the ancient Greek word sigaloeis meaning glossy or shiny, with the generic name Tethina , and refers to the body of these flies having glossy cuticle. Gender feminine.