Hydrobiosella letti Korboot

Figures 17, 36, 37

Hydrobiosella letti Korboot, 1964: 36, figs 40-57. – Neboiss, 1987: 132, figs 7, 8. – Neboiss, 1986: 101.

Holotype. Male (not seen): New South Wales, Lett R. near Lithgow, 25 Sep 1962, K. Korboot, T-6182 (QM).

Other material examined. Queensland, 1 male (CT-655), Morans Ck above Morans Falls, Lamington Nat. Pk, 28.23°S 153.13°E, 16 Nov 2011, J. Mynott & M. Shackleton .

Diagnosis. Hydrobiosella letti can be distinguished from other species in the group, especially H. bos, by the basal segment of the inferior appendages not angled dorso-mesally and harpago sub-triangular in lateral view.

Description. (Revised after Korboot, 1964; Neboiss, 1987). Wings (Fig. 17), length of forewing: male 4.5 mm.

Male. Segment IX robust, in lateral view, length about 1.4 times width, projecting and tapered basally (Fig. 37). Segment X broad-based, tapered distally (Figs 36, 37), in dorsal view, ‘tongue-shaped’, length about 1.8-1.9 times width, broadly rounded apex (Fig. 36); in lateral view, straight, with slightly bulbous apex (Fig. 37). Phallus generally tube-like; with a pair of long, slightly curved, ‘parameres’ arising from the phallus near base (Figs 36, 37). Inferior appendages in lateral view, with basal segment sub-pentangular, length about 1.4 times maximum width, harpago shorter, length about 0.7 times length basal segment, more slender, length about 2.6 times maximum width, sub-triangular, tapered to broadly rounded apex (Fig. 37).

Female. Unknown.

Remarks. A single male specimen of Hydrobiosella letti is known from the type locality in central-eastern New South Wales (latitude 33°24'S). Korboot’s (1963, fig. 45) and Neboiss’s (1987, figs 7, 8) figures have been redrawn to allow direct comparisons and to accompany the description that is revised in light of new interpretations of Hydrobiosella genitalic and wing structures. Neboiss (1987) commented on the condition of the type specimen and errors in Korboot’s original description and that the vial containing the remaining body parts had two locality labels: Lett River via Lithgow and Montville, Queensland. The recently collected male specimen from Lamington National Park in south-eastern Queensland is here referred to H.letti, although there are several minute differences in the genitalia (latitude 28°14'S).