Nothocyphon, Zwick, Peter, 2015

Zwick, Peter, 2015, Australian Marsh Beetles (Coleoptera: Scirtidae). 7. Genus Nothocyphon, new genus, Zootaxa 3981 (3), pp. 301-359 : 304-305

Nothocyphon , new genus

Type species: Nothocyphon lindensis ( Blackburn, 1892) , new combination

Diagnosis. Small (BL 1.5−3.5mm) oval to elongate-oval relatively flat marsh beetles. The transverse head rests between the slightly projecting blunt angles of the pronotum and is in dorsal view concealed by the front margin of pronotum. Eyes projecting. Mandibles short, with one small tooth or without tooth. Terminal segment of maxillary palpus bottle-shaped, of labial palpus bean-shaped, inserted at an angle on the penultimate segment. Antennae filiform, base not modified. No antennal sulcus. Pronotum with wide base, sides curving down, rounded, converging towards front corners. Unmodified ambulatory legs with paired keels on tibiae. Scutellum an equilateral triangle. Elytra unmodified. Dorsal side of body irregularly punctate, finely pubescent.

Underside. The subgenal crest meets the gular suture and then the border of head capsule next to the mouthparts, there is no buttonhole configuration. Prosternal process slender, teardrop-shaped. Receiving mesoventral groove elongate, U- or V-shaped, anteriorly open. Mesoventral process parallel, the finely incised end meets the short metaventral process. Discrimen visible over most of metaventrite. Abdominal segments 3−7 exposed, unmodified, except female N. lanceolatus n. sp.

Male: T8 well developed, S8 large, Y-shaped. T9 with straight apodemes, plate membranous. S9 soft, base rarely visible, caudally setose, mostly bilobed. Tegmen with parameres, penis with parameroids; shapes variable but no essential modifications.

Female: Ovipositor long, unmodified. Prehensor present. Bursella without major sclerites or ornaments.

Description. The body contour at rest in dorsal view is oval to elongate oval, with the wide head concealed under the slightly projecting pronotal front margin (e.g., Figs. 62 , 165−168 ). In side view the body is relatively flat to slightly domed ( Figs. 172, 173 ). Head across eyes wider than long from front of frontoclypeus to edge of occiput ( Fig. 1 ). Eyes bulging. The frontoclypeus projects little between the antennae, the small labrum is rectangular, with rounded corners. The mandibles are largely concealed, the space between their condyli corresponds to about 40% of HCW. A single or no tooth on the mandibles; if present, the right tooth tends to be larger ( Figs. 1, 2, 5 ). Mola without spinous area. The terminal segment of the maxillary palpus is bottle-shaped, narrowed in its distal half ( Fig. 6 ). The bean-shaped terminal labial palpus segment inserts subterminally on the penultimate segment ( Figs. 3, 7 ). The angle between the two segments seems to increase with the degree of dehydration, for example during preparation for mounting. Antenna ( Figs. 4 , 25): scape large, unmodified. Pedicel thinner and shorter, first flagellar segment slender, length not much different from pedicel.

The head sits between the front angles of the pronotum which are blunt but marked. Pronotum at base little narrower than the elytra ( Figs. 165−171 ). It is much longer medially than along the downcurved sides. The rear edge is sinuous, the rear angles are obtuse, rounded. In side view, the pronotum is little arched along the median line, more strongly across its anterior part. The scutellum is an equilateral triangle between the elytral bases. Humeri distinct, the elytra are gently arched, without carinae or sutural stripe. Unmodified ambulatory legs, tibiae on outside with paired carinae. Fully winged beetles.

The dorsal body surface is covered with fine semi-erect pubescence and is irregularly punctate. Punctures on head, pronotum and scutellum are granular, raised, those on elytra are normal.

Most species are of uniform brown colour (e.g., Fig. 171 ) but several have patterned pronota and elytra (e.g., Figs. 62, 63 , 165−167 ) which is often not very apparent. Distinctness of patterns seems to vary with the degree of maturity of the specimen. Further, pigment on the elytra is often difficult to distinguish from dark shades caused by the folded wings which are seen by partial transparency. Pigment patterns alone do not permit species identifications.

Lower face. The front end of the subgenal ridge joins a branch from the gular suture. Together they enter the head capsule border near the mandibular insertion ( Fig. 1 ). No buttonhole configuration. A very shallow ridge obliquely crosses the area between eye and mouthparts. The pronotal process is narrow, the tip resembling a teardrop bears fine hairs. The U- or bluntly V-shaped receiving groove of the mesoventrite is longer than it is wide in front, bordered by shallow ridges only along the sides, open in front. Mesoventral process parallel, its end finely incised, meeting the short metaventral process. Discrimen visible over most of metaventrite. Elytral epipleura narrow, smooth. Abdominal sternites 3−7 exposed, unmodified, except the usual row of microscopic piliferous granules along front edge of anterior sternites.

Males. T8: Apodemes straight, about as long as the plate, basally connected by a thin curved or angular sclerite along the antecosta (e.g., Figs. 21 , 34 ). Caudal edge with marginal setae and a microtrichial pecten ( Zwick 2013c). Distal half of plate covered with microtrichia; a band in front of the caudal edge remains usually bare. The area covered with microtrichia often has a tongue-shaped forward extension between which and the apodemes is often a paler, window-like area (e.g., Fig. 143 ). S8 is distinct, Y-shaped (e.g., Figs. 35 , 57 , 70 ). T9: Apodemes about as long as those of T8, antecosta between them weakly sclerotized. Plate soft, colourless and bare (e.g., Figs. 22 , 58 ). Thin sclerite rods resembling continuations of the apodemes may occur along the sides of the membranous plate. S9: The setose mostly bilobed caudal portion is often all that is seen, the plate is soft, usually there is no well defined base (e.g., Figs. 17 , 66 , 71 ). Penis with trigonium and parameroids, tegmen and parameres specifically distinct.

Females. Known from only a few species. Ovipositor (e.g., Figs. 15 , 39 ) slender, bacula very long, with subterminal recurrent branchlet. Gonocoxae long and slender, caudally very narrow, gonostyli small, tubular, with apical sensilla. The apodemes of T8 are shorter than the bacula but much longer than the sclerotized lateral rods of S8 which may anteriorly be connected in various ways. T8 with continuous fringe of delicate microtrichia along caudal edge. S8 is similar but caudal microtrichial fringe interrupted. Prehensor specific (e.g., Figs. 14, 16 , 28, 31, 40), bursella with small pores ( Libonatti & Ruta 2013), no large sclerites on surface.

Note. In order to be able to name the new species assignment to a genus is needed. The beetles redescribed or described in the present study share a generalized body structure and lack apomorphic character expressions seen in other genera. Some support for Nothocyphon can be derived from a recent molecular study of Australian marsh beetles ( Cooper et al. 2014).

Cooper et al. (2014) recognized an Austrocyphon -group, and three clades within it. One clade included the Austrocyphon species which grouped closely ( Cooper et al. 2014, their fig. 4).

The sister clade to Austrocyphon contained still undescribed species which were called Contacyphon spp., mostly of the lindensis- group. C. H. S. Watts has now identified several, from a draft of the present manuscript (Watts, personal communication). Specimens of N. lanceoloatus n. sp. form one cluster grouping with N. vandiemeni n. sp., N. multidentatus n. sp., and N. triangulum n. sp. Together they are sister group of N. ypsilon n. sp. This pattern generally agrees with the taxonomy proposed here.

However, Nothocyphon frater and its siblings formed the sister clade to the other two ( Cooper et al. 2014), as though it also deserved genus rank. Presently, I cannot take this step because I find nothing in body structure to justify generic separation of the frater -group from the rest.

The numerous species of Nothocyphon can reliably be distinguished by the male genitalia which, however, do not fundamentally differ from the Microcara - type ( Nyholm 1972). Similarities in the genitalia permit the provisional distinction of some groups but differences between groups are not striking, elevation to genus group rank is not appropriate. Numerous species stand by themselves, their closest relatives are unknown. Females are in most cases unknown, female genital character sets are only fragmentarily available.

Keys to males are provided. For females, users are referred to the figures of the few known ones. In view of the overall similarity between the included species, the following descriptions are essentially brief diagnoses based on terminalia. Where possible, male segments 8 and 9 are illustrated, but often without repetitive descriptive text.

Figures

FIGURES 62 – 68. Nothocyphon auritus - group. N. auritus. Male: 62, 63, variants of pattern of dorsal side; not to scale; 64, T 8 and T 9, superimposed; 65, S 8; 66, S 9; 67, penis, tegmen and parameres, superimposed. Female: 68, prehensor. 64 − 66 and 67, 68 to the same scales, respectively. Abbreviations: pd, parameroid, pe, paramere.

FIGURES 165 – 173. Habitus of Nothocyphon spp.: 165, N. lindensis; 166, N. taurus; 167, N. taeniatus; 168, N. denticulatus; 169, N. donnabuangi; 170, N. imitator; 171, N. frater; 172, N. frater, lateral; 173, N. taurus, lateral. To similar sizes, not to scale.

FIGURES 1 – 7. Head structures of Nothocyphon spp. N. lindensis: 1, head capsule with right mandible, ventral; 2, left mandible; 3, labial palpus. — N. frater: 4, antenna; 5, left mandible, ventral; 6, maxillary palpus; 7, labium. Not to scale.

FIGURES 17 – 24. Nothocyphon lindensis - group, N. taurus (17 − 20) and N. banksiae (21 − 24). 17, dorsal view of male terminalia as extracted from abdomen, superimposed components seen by transparency; semi-diagrammatic, setae of S 8 and microtrichia on T 8 not shown; 18, tips of penis and parameres of another specimen, ventral view; 19, T 9 and S 9 superimposed, caudal edge of T 9 and base of S 9 are transparent, the hollow spine lies between them; 20, prehensor; 21, T 8 and the (inverted) S 8; 22, T 9; 23, S 9; 24, dorsal view of penis and superimposed tegmen and parameres. 18 − 20 and 21 − 23 to the same scales, respectively. Abbreviations: aT 9, apodeme of T 9; hs, hollow spine; pd, parameroid; pe, paramere; tr, trigonium.

FIGURES 32 – 37. Nothocyphon lanceolatus - group, N. lanceolatus, male. 32, lateral view of everted terminalia; 33, same, dorsal view (paratype from Cradle Mtn); 34, T 8; 35, S 8; 36, penis and parameres of paratype from Hartz Mts NP; 37, same, specimen from Gordon R. 33, 36, 37 to the same, others not to scale. Abbreviations: pa, pala; pe, paramere; pd, parameroid; sp, spur of paramere; te, tegmen; tr, trigonium; S, sternites, T, tergites, with number of segment.

FIGURES 137 – 148. Nothocyphon spp., males. N. esau: 137 − 139, T 8, S 8, T 9 (from top), 140, penis and right half of paramere in ventral view, superimposed (holotype); 141, 142, trigonium of the two paratypes. — N. horridus: 143, T 8; 143, S 8; 145, T 9; 146, 147, the parameres; 148, penis. 137 − 139, 140 − 142, 143 − 146 and 147, 148 to the same scales, respectively. Abbreviations: pd, parameroid; pe, paramere; pel, lobe of paramere.

FIGURES 57 – 61. Nothocyphon auritus - group, N. vandiemeni. Male: 57, T 8 and S 8; 58, T 9 and S 9; 59, penis, tegmen and parameres, superimposed; 60, tegmen with parameres. Female: 61, prehensor. 57, 58 and 59 − 61 to the same scales, respectively.

FIGURES 69 – 76. Nothocyphon auritus - group, N. wattsi. Male: 69, T 8, with enlarged inset of grouped microtrichia; 70, S 8; 71, T 9 and S 9, superimposed; 72, penis, tegmen and parameres superimposed, dorsal view; 73, left half of same in ventral view; 74, oblique ventrolateral view of penis apex; 75, armed section of vas deferens. Female: 76, prehensor. 69 − 71 and 72, 73 to the same scales, respectively. 75 not to scale.

FIGURES 14 – 16. Nothocyphon lindensis - group, females. N. lindensis, prehensor: 14 a, dorsoventral; 14 b, lateral. — N. ypsilon: 15, dorso-ventral view of the cleared abdomen; 16, prehensor. 14, 16 to similar size, not to scale.

FIGURES 38 – 40. Nothocyphon lanceolatus - group, N. lanceolatus, presumed female. 38, S 7 with patches of porous cuticle and associated hair brushes; 39, segment 8 and ovipositor (diagrammatic); 40, prehensor, dorsoventral.