Paracyphon avicularis, Zwick, Peter, 2015

Zwick, Peter, 2015, Australian Marsh Beetles (Coleoptera: Scirtidae). 8. The new genera Cygnocyphon, Eximiocyphon, Paracyphon, Leptocyphon, Tectocyphon, and additions to Contacyphon de Gozis, Nanocyphon Zwick and Eurycyphon Watts, Zootaxa 3981 (4), pp. 451-490 : 484-486

Paracyphon avicularis , n. gen., n. sp.

(Figs. 99–102)

Type and only species: Paracyphon avicularis , n. sp.

Type material. Holotype ♂: 38.17S 145.00E VIC Mt.Worth N.P. 300m Trevorrow's Mill 28.Jan.-10.Feb.1987 A.Newton & m.Thayer \ wet scler.for. FMHD 87 235 Flight interception trap ( ANIC; damaged). Paratype ♂: AUSTRALIA, SE NSW, Kosciusko N.P. Smiggins Hole, 1800m / at light 15.I.1981 leg Hangay & Vojnitz / No.126 ( HNHM).

Diagnosis. Small, BL less than 3.0 mm. Elongate oval, fairly flat. Pronotum narrower than base of elytra, transverse with rounded rear margin and slightly projecting front angles. Maxillary palpus straight, terminal segment of labial palpus obliquely inserted. Prosternal process with drop-shaped apex, receiving mesoventral groove elongate, U-shaped. Male S8 Y-shaped (Fig. 99). Tegmen and parameres are a thin simple sclerite loop without armature (Fig. 102). Penis (Fig. 101) with capsule-like pala. No trigonium, instead with two caudal processes articulating on paired condyli formed by the sclerotized periphery of the pala. Female unknown.

Description. Habitus. BL 2.3–2.5 mm, elongate oval, BL/BW ~1.8, little convex, highest point of body behind midlength. Head and pronotum reddish brown, a darker mark across rear half of pronotum. Scutellum yellowish. Anterior fourth of elytra dark brown except lighter humerus. Dark streaks along elytral margin and suture. Posterior portion of the elytra lighter brown. Mouthparts, legs and antennae yellowish, distal antennomeres slightly infuscated. Head, pronotum and scutellum with spaced very fine granular punctures, elytra with larger normal punctures about 1.5 to 2 diameters apart. The semi-erect pilosity is brownish.

Head short and transverse, eyes large, laterally protruding, in side view lower edge only ~1–2 facet diameters from subgenal ridge. The antenna is slender, pedicel and antennomere 3 are subequal, longer than wide. Antennomere 6 is longest, ca 4x longer than wide. Distal antennomeres are barely twice as long as wide. No antennal groove, no distinct supraantennal ridge. Mandibles not studied. The terminal segment of the maxillary palpus is little longer than the penultimate, narrowed to a blunt tip. Terminal segment of the labial palpus beanshaped, standing at an angle on the preceding segment.

Pronotal front edge straight, the blunt angles slightly projecting. Rear edge semicircularly curved, disc along midline almost twice as long as laterally. A pair of inconspicuous paramedian punctures on rear edge. Elytra irregularly punctate, no striae, no depressions. Legs unmodified.

Lower side. Head: the front end of the subgenal ridge connects to a branch from the gular suture and continues to the edge of the oral cavity. Prosternal process with relatively wide drop-shaped apex, receiving mesoventral groove U-shaped, long, reaching to between front of middle coxae. The mesoventral process is well developed, parallel, caudally finely incised, part of the metaventral process is exposed. The discrimen extends over most of the metaventrite. Abdominal sternites unmodified. Elytral epipleura narrow.

Male. Plate of T8 covered with microtrichia, rear edge gently arched, with microtrichial pecten and sparse long setae. The apodemes are straight, taper caudally and fade away in the plate. The area of the plate beween the apodeme and the angular fine sclerite connecting the apodemes is a bit paler than the rest (Fig. 99). S8 is large, Yshaped, with a short unpaired and long divergent caudal rods. The plate is reduced to two small caudolateral plaques with a few setae. T9 has straight apodemes that are neither connected nor continued onto the pale, soft, hairless plate (Fig. 100). S9 is short and broad, the anterolateral angles are distinct but the middle of the base is not. The plate is divided into two wide caudal lobes, each with some long setae (not shown).

The ribbon-like thin tegmen plus parameres form an oval loop with enlarged flap-like unarmed apices (Fig. 102). The penis has an oval capsule-like pala with wide, strong, sclerotized margin supporting a pair of caudal appendages but no trigonium (Fig. 101). Each appendage is composed of a slender strongly sclerotized hook and a superimposed barely sclerotized pale long flap. The base of each hook is an anteriorly pointed triangular sclerite, tips meeting medially. More laterally, each hook rests on a knob projecting from the sclerite ring of the pala. On the outside each hook bears a subbasal swelling. The apex resembles a bird's head, the beak directed sideways. The long flap is spatula-shaped, its rounded caudal end is wider than the base. The front ends of the flaps project into the oval space of the pala where they are connected, forming a triangular sclerite with median keel which in dorsoventral view appears like a slender spine. There are remains of strong muscles between the keel and the sclerotized ring of the pala.

Female. Unknown.

Note. Paracyphon avicularis is an isolated species that fits into no known genus, close relatives are not known. The overall body structure of P. avicularis agrees, among other, with Austrocyphon, Tasmanocyphon , and Nothocyphon, except for the puzzling contrast between the wide prosternal process and the long and narrow receiving mesoventral groove. However, the replacement of the trigonium by paired apparently movable appendages does not at all agree with these genera. Instead, it reminds one of conditions observed in the genera Contacyphon and Calvarium (s. str.) (Australian species: Zwick 2013b, 2014b) but P. avicularis belongs to neither of these genera. It does not exhibit the buttonhole configuration of the head sutures and also not the rhomboid mesoventral groove characteristic of Contacyphon whose males never have a developed S8. Species of Calvarium are (among other) distinguished by a deep antennal furrow. The movable appendages of the penis together rest on one single median condylus while here there are two separate condyli. The pair of small punctures at the pronotal rear edge do not suggest close affinities with Heterocyphon ; compare Leptocyphon furcalonga .

Etymology. The generic name combines the Greek suffix para, next to, besides, with the classical name, Cyphon . The Latin adjective avicularis , bird-like, related to birds, alludes to the shape of the male genital hooks.