Ypsiloncyphon velatus, 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

Ypsiloncyphon velatus , n. sp.

( Figs. 90–98 )

Type material. Holotype ♂ WA: “ 15.38S, 126.15E, CALM site 28/3 4 km W of King Cascade W.A. 12–16 June 1988 T.A.Weir \ at light closed forest“. Paratypes: 11♂ with the same data (all ANIC).

Additional material assigned with doubt. Morph 1, NT: 1♂ “ 12.22S 133.01E 6km SW by S of Oenpelli. N.T. 6.vi.73 Upton & Feehan” ( ANIC). Morph 2, WA: 11♂ “Cadjeput Rockhole E of Woodstock Station 21°31'55''S, 119°08'57''E 29 September 1988 B.P.Hanich et al. \ BPH 29–11AI UV fluorescent light at night 6:00–8: 45 p. m.“ ( WAMP, Reg. Nos. 42897, 42899–42908).

Habitus. Elongate oval, BL /BW 1.9. BL is 1.6–1.8 mm in the typical morph, 1.7–1.9 mm in Morph 2, and 1.8 mm in Morph 1. Labrum, legs and antennae yellowish to light brown, antennae distally slightly infuscate, distal flagellar segments about twice as long as wide. Dorsal side dark brown to black, the semi-erect pilosity brownish. Punctation dense, granular punctures on head and pronotum, normal ones on elytra. Punctures on head finer than others, except on scutellum.

Male. Apodemes of T8 half as long as those of T9 ( Figs. 90, 91 ). The capulus occupies ~30% of the length of S9 and is long and slender, anterior end little enlarged. The length difference between the two blades is moderate, both with short slender ends. The wide basal portion of the shorter blade is longer than of the longer blade, which narrows earlier ( Figs. 94, 96, 98 ). Penis with narrow base, widening caudally and then again restricted. Basal half of trigonium almost parallel, medially constricted and apically again wider, with conical tip. Parameroids with narrow basal section, then medially expanded, caudally slightly divergent but even then veiling part of the trigonium ( Figs. 93, 95, 97 ). Tegmen and parameres ( Fig. 92 ) without modification, not distinctive.

Variation. S9 varies little between individuals but by the trigonium shape, three morphs can be distinguished. Each of the two larger samples is very uniform:

Typical morph (WA) ( Fig. 93 ): Penis narrow where parameroids and trigonium separate, caudally first widened and then again narrowed in a curve. Trigonium with moderate constriction near midlength, then again widened posteriorly, but less so than at base.

Morph 1 (NT) ( Fig. 97 ) differs by the very wide front end of the pala and the wide, almost rhomboid distal part of trigonium.

Morph 2 ( Fig. 95 ) is wider than the other at the point where parameroids and trigonium separate. The overall penis contour then continually narrows in an almost straight line to the tip. Trigonium at base relatively wider than in the others.

Female. Unknown.

Notes and etymology. There are certainly more habitats supporting Ypsiloncyphon species between the CALM-site and the Mitchell Plateau, and also towards Oenpelli, than those presently sampled, and intermediate morphs are expected to occur. It can presently not be decided if the (seemingly distinct) populations separated by the Great Sandy Desert belong to different biospecies or are alternatively conspecific local variants as I presently assume. The separation by the desert may be relatively recent. After all, Y. virgulifer n. sp. occurs both South and North of the desert. Additional evidence is also expected from the future discovery of females.

The Latin adjective velatus means “veiled, partly hidden,” an allusion to the trigonium which is distally partly concealed by the parameroids.

Figures

FIGURES 90 – 98. Morphs of Ypsiloncyphon velatus, n. sp.: 90, T 8; 91, T 9; 92, tegmen and parameres; 93, 95, 97, penis; 94, 96, 98, S 9. All to same scale. 93, 94, Morph 2 from Cadjeput Rockhole; 95, 96, holotype; 97, 98, Morph 1 from near Oenpelli.