Ypsiloncyphon mutilatus, 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 : 26

Ypsiloncyphon mutilatus , n. sp.

( Figs. 84–89 )

Type material. Holotype ♂ paratypes, 1♂ 1♀: “ Papua New Guinea: Laloki [9°21'45"S 147°13'31"E], CSIRO Screw Worm Lab, Jan.-Mar.1987 S.Bakker ex flight intercept. trap” (all ANIC).

Additional material studied. 1♂ 2♀(all or part of genitalia lost) with the same data ( ANIC).

Habitus. Uniformly blackish brown, appendages yellowish. Shape of body and pilosity strongly sexually dimorphic. Male. BL 1.8mm, BL /BW ~1.6. Oval, stout, body strongly domed. Elytral punctation very dense and fine, a bit rough. The short decumbent whitish hairs in the usual arrangement, that is, directed obliquely posterolaterally near scutellum, essentially posteriorly elsewhere. Female. BL 1.8–2.2mm, BL /BW ~1.9. Elongate, parallel-sided, flat. Pilosity very long, decumbent, with faint silvery sheen. On the head, setae point essentially anteriorly, locally sinuous. The dense granular punctation on pronotum almost concealed by long thick hairs which are directed laterally, away from the middorsal line. Similarly, long hairs in anterior third of elytra are directed laterally, away from the suture. Further posteriorly there is a gradual transition to hairs of normal length and normal posterior direction in the caudal half of elytra. Pilosity of scutellum fairly long, pointing posteriorly.

Male. Apodemes of T8 hardly longer than the transverse, caudally rounded plate. T9 barely sclerotized, much narrower than T8, its apodemes more than twice as long ( Fig. 84 ). [S9 not available, lost during dissection]. Tegmen and parameres very slender and long, the unpaired base anteriorly pointed ( Fig. 85 ). Penis long, the pala occupies about 1/4 of total length. Between the bases of the parameroids the parallel base of the trigonium is visible. In front, it supports a tongue-shaped appendage. Trigonium nearly parallel over most of its length, tapering only in distal quarter. Parameroids much longer than trigonium, ending in long narrow apices ( Figs. 86, 87 ).

Female ( Figs. 88, 89 ). S7 with nipple-shaped prolongation which at rest is folded anteriorly, not exposed. Sclerites of S8 resembling a tuning fork, paired and unpaired branches of similar length. Vulvar sclerite large, very similar to Y. longus , except the bridge sclerite near midlength and the caudolateral lobes more spread out, with uneven surface instead of being smooth and cap-like, and sharply pointed. Dictyon large, with many cells, like in Y. longus .

Notes and etymology. The Latin adjective mutilatus describes the poor condition of several specimens, particularly the loss of male S9 during dissection. Males are nevertheless immediately recognized by parameroids much longer than the trigonium and the filament-like tip of the former. In all other species parameroids and trigonium differ less in length, the apices of parameroids are rounded. Forebody pilosity renders females unique.

Figures

FIGURES 84 – 89. Ypsiloncyphon mutilatus, n. sp. (paratypes). 84, male T 8 and T 9, superimposed; 85, tegmen and parameres; 86, penis in oblique view. 87, penis, dorsal view; 88, female terminal segments with vulvar sclerite; 89, vulvar sclerite. 84 – 87 to the same scale.