Ypsiloncyphon pusillus, Zwick, Peter, 2014

Zwick, Peter, 2014, Australian Marsh Beetles (Coleoptera: Scirtidae). 6. Genera Calvarium Pic, Papuacyphon Zwick, and Ypsiloncyphon Klausnitzer, Zootaxa 3846 (1), pp. 1-41 : 29-30

Ypsiloncyphon pusillus , n. sp.

( Figs. 99–102 )

Type material. Holotype ♂ WA: “ 14.51S 125.50E, 1 km S mining camp Mitchell Plateau 13 May 1983 WA I.D.Naumann, J.C. Cardale ex ethanol“ ( ANIC). Paratype ♂: “ 14.30S 125.47E WA, Mitchell Plateau, Boab Camp besides Crystal Creek 3 May 1992 P.J.Gulla, at light“ ( ANIC).

Habitus. Flat, relatively slender, BL 1.7–1.8 mm, BL /BW ~1.7. Body uniformly brown, appendages yellowish. Punctation fine and dense, pilosity semi-erect, fine, light brown with pale reflection.

Male. Apodemes of T8 barely longer than the caudally strongly rounded plate ( Fig. 99 ). T9 soft, narrower than T8, its sinuous apodemes about 1.8 times longer than those of T8 ( Fig. 100 ). Slender capulus of S9 almost 1/3 the length of the longer blade, the base is little enlarged, obliquely oval. Longer blade tapering to a long filiform apex, the shorter blade abruptly restricted to a terminal filament which is little longer than maximum width of the same blade ( Fig. 102 ). Penis little shorter than S9. Pala long and narrow, anterior plate distinct. Penis very wide where trigonium and parameroids originate. Basal third of trigonium wide, parallel, caudally strongly waisted, narrower than narrowest section of pala. Caudal third of trigonium again widened, elongate oval. Parameroids longer than trigonium, basally half as wide as trigonium, near midlength a bit wider, caudally narrower, rod-like. Parameroids do not conceal the trigonium, separate, all freely visible. The parameres are slender, caudally tapering rods, their narrow common base corresponds to the tegmen ( Fig. 101 ).

Female. Not known.

Note and etymology. In the long and narrow capulus and pala as well as the wide shorter blade of S9 with abruptly offset short apical filament the male genitalia resemble the morphs of Y. velatus n. sp. However, the extreme constriction of the trigonium and the narrow rod-like parameroids differ. The beetle is very small (the Latin adjective pusillus ) which its name describes.

Figures

FIGURES 99 – 102. Ypsiloncyphon pusillus, n. sp., male holotype: 99, T 8; 100, T 9; 101, penis lying over tegmen and parameres; 102, S 9. 99 & 100, and 101 & 102 to the same scales, respectively.