Oecetis ada sp. nov.

Figures 51–53, 74

Material examined. Holotype. Male, NT, Litchfield National Park, Ada Creek, at jump up, 24–25 Jun 1992, Wells and Webber (NTM).

Diagnosis. The patches of wing scales clearly place this species in the pechana -group, but, like O. gilva, it lacks a paramere in the very short phallus; and the pre-anal appendages are unusually long for a pechana -group species, being over 3 times longer than wide.

Description. Wings with short hair on veins, forewing with a patch of scales. Male anterior wing length, 6.6 mm. Abdominal segment IX narrow, lateral angles produced; segment X about as long as pre-anal appendages, slender in dorsal view. Genitalia, see figs 51–53. Pre-anal appendages elongate-ovoid. Inferior appendages stout at base, in ventral view tapered to rounded apices; in lateral view, with a triangular basi-dorsal lobe, and basi-dorsal pouch. Phallus about length of 1 abdominal segment, with a sharply returned, pointed apex; paramere absent.

Distribution. Known only from the holotype male from the north of the NT.

Etymology. Named for the type locality.

Remarks. Although this species lacks a paramere it clearly groups with pechana -group species on the basis of the general form of the phallus, wing venation and presence of scale patches.