Austrocyphon

Zwick, Peter, 2013, Australian Marsh Beetles (Coleoptera: Scirtidae) 4. Two new genera, Austrocyphon and Tasmanocyphon, Zootaxa 3706 (1), pp. 1-74 : 6

The Austrocyphon -complex

In collections, almost all small Scirtidae with walking hind femora (as opposed to saltatorial legs) were originally sorted as Cyphon , in some wide sense.The preliminary generic key ( Watts 2011) had two couplets leading to small beetles more or less resembling the genus Cyphon in habitus.

Attempts to recognize the Austrocyphon -complex by habitus or general body structure failed, but male genitalia immediately identify the group. In my earlier comparison ( Zwick 2013b) of taxa with Cyphon coarctatus Paykull , the type species of Cyphon , Austrocyphon and Tasmanocyphon were together called the Cyphon doctusgroup . The new genera exhibit none of the characters that distinguish true Cyphon species ( Table 1 ).

The male genitalia of members of the Austrocyphon complex are distinguished by the following (see Fig. 7 ): the pala, or penis base, is surrounded by a narrow sclerite ring, the ends of which are connected by a transverse bridge supporting the trigonium; the parameroids inserting laterally at the same level extend backward beyond the trigonium. However, unlike most Scirtidae they are not separate lateral appendages but merge with each other dorsally from the trigonium. Together, they form a single common sclerite with transparent centre so that the trigonium stands in front of a window-like unsclerotized area, the foramen, and is surrounded or framed by the fused parameroids.

The above character expressions are regarded as apomorphic. For details of my reasoning see Zwick (2013b).

Females of only a few species were reliably associated, either from pairs taken in copula, or in the few species with characteristic colour patterns or surface structure that can be identified ad hoc. The genital tract of Austrocyphon females lacks prehensors or other specific sclerotized structures. Poorly delimited vague sclerotization of the oviduct close to its end inside the ovipositor or feeble vulvar sclerites are observed in a few. The delicate cuticular ornaments (for example, Fig. 9 ) on the wall of the large accessory gland ( Nyholm 1969, 2002) are not specific. Austrocyphon females lack distinctive characters of their own and can therefore not reliably be distinguished from many other so-called Australian Cyphon , for example of the Cyphon lindensis -group.

Figures

FIGURES 6 – 9. Austrocyphon genitalia. 6, 7, Austrocyphon ovensensis, male from VIC, Yarra Junction: 6, abdominal tip with everted genitalia in side view; 7, penis in ventral view; broken line indicates dorsal flange of frame. Not to scale. 8, 9, A. doctus (Lea), female: 8, segment 8 and ovipositor in dorsal view; not to scale. 9, wall of accessory gland of genitalia (cleared), diagrammatic combination of surface view and optical section through edge. C, centema; fo, foramen; gs, gonostyle; gx, gonoxocite; op, apodeme of ovipositor; P, pala; Pe, parameroid; S, sternite (with ordinal number); sp, spur; T, tergite (with ordinal number); Tn, tegmen; Tr, trigonium.