Leptocyphon, 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 : 476

Leptocyphon , n. gen.

Type species: Leptocyphon furcalonga , n. sp.

Diagnosis. Small, BL ca 3mm. Slender, flat ( Figs. 76–78 ). Pronotum transverse, short, little narrower than the elytra. Base sinuous, projecting towards scutellum, laterally straight, rear angles almost rectangular, blunt. Sides converging towards the rounded front corners between which the front margin is straight. Sides of elytra little curved, epipleura narrow. Head a little wider than long, no antennal groove. Eyes moderately projecting. Subgenal ridge joining a branch from the gular suture, together they meet the edge of the oral cavity ( Fig. 79 ). Only right mandible with small tooth, or both toothless, no spinules in molar area. Palpi straight, antennae and legs unmodified. Prosternal epipleura reaching to level of front coxa. Prosternum very small ( Fig. 80 ), prosternal process reduced, not reaching back beyond the coxae, extremely narrow. Receiving mesoventral groove indistinct, mesoventral process very narrow but complete ( Fig. 81 ). Male S8 large, Y-shaped, with long unpaired sclerite ( Figs. 83 , 90 ). No stylus. Female (known only of L. furcalonga ): bacula firmly connected to gonocoxites, not articulated, gonostyle wart-like ( Fig. 87 ); prehensor complex ( Fig. 88 ).

Notes. The two included species are very similar in habitus and body structure but differ strikingly in the shape of the male genitalia. I include them with hesitation in the same genus. When the female of the second species becomes known a decision will be easier. Both species occur in the extreme SW of Western Australia and were rarely collected.

Describing and naming a small slender Australian marsh beetle with blunt pronotal front angles is difficult. The available generic key ( Watts 2011) leads to Pseudomicrocara or Cyphon (in the former wide sense) which are separated by size (overlapping) and small spines in the molar area, which varies in Pseudomicrocara . Therefore, new taxa resembling Pseudomicrocara (s. l.) need to be compared to the type species, P. orientalis Armstrong, 1953 , see below. What the closest relatives of Leptocyphon may be is uncertain.

Etymology. The generic name refers to the thin prosternal and mesoventral processes and connects Gree k lept os, thin, with the classical name, Cyph on.

Figures

FIGURES 76 – 79. Leptocyphon furcalonga, n. gen., n. sp.: 76, 77, habitus dorsal and lateral; 78, forebody, oblique frontodorsal view; 79, cleared head, ventral. Not to scale.

FIGURES 80 – 88. Leptocyphon furcalonga, n. gen., n. sp.: 80, 81, ventral views of prothorax and mesoventrite; male: 82, T 8; 83, S 8; 84, T 9 and S 9, superimposed; 85, penis; 86, tegmen and parameres, with enlarged detail of paramere structure. Female: 87, cleared terminalia, with contours of sternites 6 and 7; apodemes of S 8 shown in black; 88, prehensor. 80 – 84 and 85, 86 and 88 to the same scales, respectively. aT 8, apodemes of T 8; ba, bacula of ovipositor; lc, laterocervicalia.

FIGURES 89 – 93. Leptocyphon quadricornutus, n. sp., male: 89, T 8, with enlarged detail; 90, S 8; 91, S 9; 92, tegmen and parameres; 93, penis. 89, 90 and 91 – 93 to the same scales, respectively.