Prionocyphon neboissi, Zwick, 2016

Zwick, Peter, 2016, Australian Marsh Beetles (Coleoptera: Scirtidae). 9. The relations of Australasian Ypsiloncyphon species to their Asian congeners, additions, mainly to Petrocyphon and Prionocyphon, and a key to Australian genera of Scirtinae, Zootaxa 4085 (2), pp. 151-198 : 174-175

Prionocyphon neboissi , n. sp.

( Figs 42−44 , 54−60 , Table 2)

Type material. Holotype 1♂: Marysville, Vic. 11.11.1957 A.N. \ Helodidae det. A.Newton 1981 (T-22031; on card, in poor shape) (MV). 1♂ Paratype: 35.16S 149.06 ACT nr. light trap, Black Mtn. 15 July 1993 W.Dressler under bark (ANIC).

Habitus. BL 2.9 mm, BL/BW ~1.6. Slender, elongate oval, sides of anterior 2/3 of elytra almost parallel. Head, pronotum and scutellum with fairly large, deep punctures which are barely one diameter apart. Punctures on elytra still larger. Entire dorsal side yellowish brown, covered with yellowish shaggy hairs. Head strongly transverse, eyes bulging. Clypeus with projecting square lobes on either side of labrum. Antennal flagellum not serrate. Second flagellomere more than twice as long as wide at apex, the others shorter, about twice as long. Mandibles unmodified, maxillae and labium not studied. Subgenal ridge with distinct buttonhole, rest of underside of head and thorax not studied.

Male. Setation of abdominal sternites heterogenous ( Figs 42–44 ). Apodemes of T8 not longer than the transverse plate, indistinctly connected by a transverse sclerite. Caudal portion of plate covered by irregular microtrichia, the straight rear edge with sparse fringe of long setae ( Fig. 54 ). S8 missing. Apodemes of T9 longer, thin, distinctly curved, the colourless bare plate without defined shape ( Fig. 55 ). S9 large, the wide base with paired sclerotized stripes resembling apodemes. Caudal part with long pilosity, rear edge rounded ( Fig. 56 ).

Tegmen ( Fig. 57 ) large, the sclerotized front with wide U-shaped notch. The parameres are two large plates ending in triangular pointed lobes separated by narrow gap. Numerous minute sensilla (socketed setae) on outside near widest part, the slender tips with extremely fine pilosity or microtrichia; details not visible at 630×. The long and slender styles bear distally some fine microtrichia-like structures.

Penis ( Figs 58, 59 ) slender, the rounded pala only a little wider than the tongue-shaped caudal end which probably represents fused parameroids. A little beyond midlength originates the narrow, slender trigonium which resembles a fish bone. Its minimally thickened apex bears a few asperities and extends well beyond the penis tip. An additional structure of unclear homology ( Fig. 60 ) is ventrally loosely connected to the penis, consisting of a short straight rod which divides into two long struts which first lie close together but diverge caudally. Each strut ends in an inwardly curved tube with a colourless process at tip. On the side of the struts directed towards the penis is a membranous flange ending in transparent tongue-shaped lobes extending further caudad than curved horns. In the paratype a very thin clear endophallus is seen to attach to the forked region of said sclerite. The wide section of the endophallus contains a few strongly curved and sharply pointed seta-like structures (inset between Figs 58, 60 ).

Female. Unknown.

Note. There are no similar species.

Etymology. Named in memory of the collector of the holotype, the late Arturs Neboiss with whom I was in contact for a long time, because of our shared interest in Plecoptera. He was curator of the insect collection at the then National Museum of Victoria in 1972. He allowed me to work in the collection, and helped in various ways.

Figures

FIGURES 42 − 44. Prionocyphon neboissi n. sp., heterogenous pilosity on abdominal sternites. Figs. 42 and 43 to the same scale.

FIGURES 54 − 60. Prionocyphon neboissi n. sp., male. 54, T 8; 55, T 9; 56, S 9; 57, tegmen with parameres and styles; 58, penis, the accessory sclerite lies over it in oblique position (paratype); 59, 60, penis and accessory sclerite, beneath it an enlarged detail of the endophallus attaching to it (holotype). 54 − 56, 57 − 60 to the same scales, respectively.