Prionocyphon yarraensis Watts 2010
Creators: name: Zwick, Peter
Publisher: name: Zenodo
Year: 2016
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Coleoptera
Scirtidae
Prionocyphon
Prionocyphon yarraensis

description: Prionocyphon yarraensis Watts, 2010b
(Figs 81–86, Table 2)
Material studied. 1 ♂: 36.36S 149.23E NSW Brown Mountain 26 Dec. 1988 C. Reid beating bushes at lookout (ANIC).
The present specimen is 3.3 mm long, a little less than the holotype. Habitus and colouration agree with the description of the type.
Elongate, sides of elytra almost parallel, body fairly flat. Yellowish brown, antenna filiform, not serrate. Flagellomeres slender, 3 times longer than wide. Yellow pilosity long. Punctures on head and pronotum very fine, those on elytra large. Clypeus with large divergent lateral lobes. End of subgenal ridge raised, separated from raised edge of oral cavity by a distinct narrow gap (buttonhole). Pilosity of abdominal sternites S3–5 with many large sensilla, S6 and S7 only with straight socketed setae, setation on S7 twice as dense as on other sternites.
The genitalia of the present beetle broke during dissection, damaging the basal plate (bp) and destroying the original connection of the tegmen and penis to the basal plate. The penis (Fig. 84) and both halves of the tegmen (Fig. 85 shows one of them) lie flat in a slide and are seen in side view. A photograph of the holotype genitalia slide (courtesy C.H.S. Watts) shows the intact structures, in dorsal view, as drawn by Watts (2010b: fig. 42; reprinted and annotated in Fig. 86). In dorsal view, the basal plate is in the background and not seen at all while the curved tube of the pala appears like a single median structure. My description is based on both supplementary views, corresponding details are labelled in Figs 84–86.
Male. T8 (Fig. 81) with short straight incompletely connected apodemes, plate transverse, with rounded rear margin. A mixed band of microtrichia and small setae in front of rear margin. Setae along rear margin a bit larger than others. S8 absent. T9 with curved incompletely connected apodemes, plate membranous, bare, with no defined shape (Fig. 82). S9 with wide front margin, plate membranous except a wide U-shaped sclerite band which ends in the weak sclerotisation of the widely separate rounded caudal lobes which bear setae laterally and caudally (Fig. 83).
Tegmen H-shaped, two strong anterior rods (te1, te2), at a considerable distance from their front ends, connected by a transverse bar (tb) whose middle articulates with the pala (pa). Basal rods continuing caudally beyond this point and ending in an upcurved sclerotized (sl) and a hyaline lobe (hy). Parameres subterminally attached to rod and partly enveloping penis (Fig. 86). Large elongate main lobe (ml) with rounded apex, medially bearing a low ridge with a few small denticles (dr). On the outside attaches the stylus (sty), which in full view is a large hyaline lobe with a caudal fringe of long delicate hair-like processes (which are not shown in Fig. 86).
Pala (pa) a U-shaped tube (Fig. 84). Precise shape of basal plate (bp) and original articulation of pala and middle of transverse bar unclear. It is not visible in the holotype slide and not shown in Fig. 86. Trigonium (tr) a long curved tube containing a wide sperm duct (sd) with a well defined ventrobasal opening (sd-o). Sperm duct ending at trigonium tip, between the three apical tips. Ventrally from trigonium originates a slightly wider, laterally spinulose, long process with rounded apical lobe with senory pores, probably representing fused parameroids.
Note. The new record considerably expands the range of P. yarraensis which was only known from near Warburton, VIC. The connection between the penis and tegmen via a basal plate agrees with P. monteithi and P. warra, but P. yarraensis is an exceptional beetle without close relatives.
description: Published as part of 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, pp. 151-198 in Zootaxa 4085 (2) on pages 184-186, DOI: 10.11646/zootaxa.4085.2.1, http://zenodo.org/record/1052535