Austrocyphon submersus, Zwick, Peter, 2013

Zwick, Peter, 2013, Australian Marsh Beetles (Coleoptera: Scirtidae) 4. Two new genera, Austrocyphon and Tasmanocyphon, Zootaxa 3706 (1), pp. 1-74 : 65-66

Austrocyphon submersus , sp. n.

( Figs. 218–220 )

Type material. Holotype ♂: Mossman Gorge, N.Q., under stones in river, 22.x.66, E.B.Britton (teneral specimen; QLD; ANIC).

Habitus. BL 2.0 mm, BL/BW ~1.6. Specimen in poor condition, elytra twisted and curled, shape and dimensions difficult to assess. Dark greyish-brown. Punctation unusually fine and dense. Pilosity strikingly dense, a greyish pelt.

Male. T8 narrow, apodemes little longer than plate, caudal margin medially shallowly excised. There is no pecten, but microtrichia on the plate project over the edge and form a fringe. Medially some additional setae present. S8 a Y-shaped small bare sclerite.

T9 longer than T8, apodemes slender, as long as the plate. Plate with large, almost circular notch surrounded by two pairs of slender, regularly curved sharply tipped processes.

S9 only partly visible, the caudally bilobed, pilose portion is distinct, the tongue-shaped anterior portion is almost transparent, its connection with the setose portion not recognized.

U-shaped base of parameres forking into two very slender, caudally acutely pointed parameres which seem to bear membranous flaps or flanges before the long acute tips.

Penis much longer than segment 9 and parameres, pala long, medially constricted (possibly an artifact during flattening of the bent base in the preparation), fused parameroids and trigonium even longer, narrower than pala. Sides of parameroids with trichoid-like fine cuticular stuctures. There is no distinct foramen. Trigonium very long and slender, gently narrowing to a long, downcurved hook. Basally from it are a few fine cuticular asperities.

Notes. The genitalia of the teneral specimen could not be satisfactorily dissected. There is no similar species. The penis structure agrees well with Austrocyphon . However, the only adult male Scirtidae I have seen under water were occasional specimens of the genus Hydrocyphon Redtenbacher in the Northern Hemisphere. This caused me to check the head structure. Unlike Hydrocyphon the present specimen has slender terminal palpus segments and fully developed mouthparts, including mandibles with sharp incisivus, the right one additionally with a large, the left with a small tooth. The unusual little beetle belongs definitely in Austrocyphon . Whether it regularly lives under water is unknown.

Etymology. The specific name is a Latin adjective stating that the beetle was under water when it was collected.

Figures

FIGURES 218 – 220. Austrocyphon submersus sp. n., male. 218, T 8 and S 8; 219, superimposed T 9, tegmen with parameres, and S 9, ventral view; 220, penis. P, paramere; S 9, sternite 9; T, tegmen; T 9, tergite 9. All to the same scale.