Leptocyphon furcalonga, 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 : 477-480

Leptocyphon furcalonga , n. sp.

( Figs. 76–87 )

Type material. 1 ♂ holotype, 6 ♂ paratypes: 20km NE Cervantes [30.5022S, 115.0681E], 20-23 Aug.1987 WA, C.Reid ex Acacia ( ANIC; the entirely cleared holotype was dissected and mounted in Euparal, on several pinned slides; 1 PT in PZ); 1 ♂ paratype: 33.48S 115.17E, Creek 8km N of Osmington, WA, 15.xi.69, E. Britton. 1♀ paratype: 33.39S 115.01E, 1km S of Yallingup WA 4 Oct.1981, I.D.Naumann, J.C.Cardale ex ethanol ( ANIC).

Habitus. BL 2.4–3.2 mm, BL/BW ~1.8. Body elongate, the almost parallel elytra widest a little behind midlength of elytra which are more than five times longer than the transverse pronotum. Most specimens dark brown to almost black, some ( Figs. 76–78 ) with ochre pronotum and elytra. The semi-erect pilosity is greyish. Elytra with very fine dense punctation. The punctures on head and especially pronotum are much larger, granular, almost pearl-shaped, barely one diameter apart.

Head ( Fig. 79 ) about 1.25 times wider across the eyes than long from occiput to front of frontoclypeus. Eyes distinctly projecting. Antenna long and slender, scape ovoid, without anterior edge, pedicel smaller than scape, ovoid. Antennomere 3 thinner than pedicel but as long as it, conical. Distal antennomeres about twice as long as wide at apex. Right mandible with a small tooth, left without tooth. Maxillary palpus unmodified, terminal segment apically narrowed, tip blunt. Terminal segment of labial palpus bean-shaped, inserted terminally on penultimate segment.

The pronotum is transverse, twice as wide at base as its length along midline. The rear margin projects towards the scutellum, the rear angles are about rectangular, the curved sides converge towards the blunt front angles which do not project. The notum is a little domed, side margin in lateral view straight. A pair of small paramedian pits at the rear pronotal margin. In the whole mount of a cleared specimen they resemble minute punctures. Legs ambulatory, unmodified.

Underside: The subgenal ridge runs on the lower face of the head, far from the eye. In front it meets a short branch coming from the end of the gular suture, together they enter the side edge of the oral cavity ( Fig. 79 ). The short and thin, blade-like prosternal process projects barely back beyond the coxae, its tip is insignificantly widened, with single hairs ( Fig. 80 ). The mesoventral groove is poorly circumscribed and shallow. It is an anteriorly open small triangle ( Fig. 81 ), no vertical carinae in front of it on vertical front of mesoventrite. Mesoventral process narrower than an antennomere but separating the coxae completely. Its finely incised end meets the front of the metaventrite, the metaventral process is barely developed. The discrimen extends over ¾ of the metaventrite. Abdominal sternites unmodified.

Male. T8 with pentagonal plate, apodemes short, straight, basally connected by fine rods delimiting a deep backward incision into the plate. Most of the plate is rough, densely covered with microtrichia, the interspersed true setae are barely noticeable. Microtrichia and socketed setae along the caudal margin are of similar length. S8 large, sclerite Y-shaped, with very long unpaired branch, the weakly sclerotized plate reduced to lateral plaques with few setae ( Figs. 82, 83 ). Apodemes of T9 well developed, basally connected by an angular sclerite. The plate is membranous, bare and short. S9 is short, two indistinct sclerotized stripes support the semicircular plate which is caudally pilose ( Fig. 84 ).

The slender penis is very long ( Fig. 85 ). The calyx-shaped pala supports long flat rod-like parameroids. They are narrow, apparent width varies with position. Their apices are short, cap-like, with sensory pores. The trigonium is much longer than the parameroids, very slender in its basal half, then gently widened and deeply divided into two narrow parallel branches. Each branch bears apically a fine membranous process or flagellum.

Base of tegmen ( Fig. 86 ) spade-shaped, with strongly sclerotized frame and membranous centre. From the membranous centre rises a pair of long paramedian weakly sclerotized blades with sensory pores in distal half and a few sensory pegs near the rounded tip. From the sclerotized sides of the tegmen originate very long soft processes tapering to a long acute tip. There is a dense rough pelt of pointed scales (detail in Fig. 86 ), except basolaterally.

In specimens with everted genitalia, the fork of the penis is directed dorsad, the median paramere blades are wrapped around the dorsal part of the penis. The pelted acute processes diverge widely.

Female ( Figs. 87, 88 ). S7 with slightly angular apex, other sternites unmodified. Ovipositor modified, the bacula are via a plate rigidly connected with the gonocoxites, the usual articulation is missing. The gonocoxites are slender triangles with sclerotised barb-like basolateral angles. A deep notch separates them from an elongate weak sclerite from which the long bacula extend forward. The stylites are wart-like, with one sensillum near the base and another at the tip. T8 large, soft, shape not recognizable, apodemes long. S8 is a triangular cone with microtrichia to which two short anteriorly widely separate apodemes (black in Fig. 87 ) attach. Prehensor ( Fig. 88 ) composed of a transverse sclerite bar which is laterally connected to cuticular folds densely covered with microtrichia. The bar has a short median extension. Two narrowly separated triangular plates with strong teeth along the sides and finer ones along the wide caudal edge lie on the opposite side of the gonoduct. Bursella not observed.

Notes.The minute pronotal pits suggested this might be an exceptionally small species of Heterocyphon . However, there are profound differences, e.g., several mandibular teeth in Heterocyphon ( Watts 2009) . Heterocyphon species (also the single western species, H. occidentalis Watts which I examined in ANIC) have a large lanceolate prosternal process, the long tip resting in an elongate U-shaped mesoventral groove. In side view the prosternal process appears bent because there is a stepwise decrease from the thick front part to the flat pilose posterior portion.

Paired punctures (also called "small depressed areas" ( Armstrong 1953), "pits, indentations" ( Watts 2009), or "Porenpunkt" (Klausnitzer 2013) at the base of the pronotum mark the point where the posterior and lateral carinae of the pronotum meet with the medial edge of the pronotal hypomeron on the underside. This detail is variably expressed in Heterocyphon ( Watts 2009) . It received not much attention in the past but was also mentioned in the Australian Peneveronatus ( Watts 2009) and in the northern hemisphere genera Nyholmia Klausnitzer, Exneria Klausnitzer, and Yoshitomia Klausnitzer (Klausnitzer 2013).

The female of L. furcalonga lacks hair patches on S4 described in females of Heterocyphon which (from fig.

16 in Watts 2009) have articulated gonocoxites with an obliquely inserted subterminal stylite. There is no information on prehensors in Heterocyphon .The rigid connection of the bacula to the sharply pointed gonocoxites with a miniature gonostyle suggests that eggs are laid into some substrate.

Etymology. The name is a noun in apposition composed of two Latin words meaning "the long fork", describing the shape of the trigonium.

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.