Cycreon Orchymont, 1919

Shatrovskiy, Alexander, 2017, A new species of Cycreon d’Orchymont, 1919 from Singapore (Coleoptera: Hydrophilidae: Megasternini), Zootaxa 4317 (3), pp. 588-592 : 588-589

publication ID	https://doi.org/ 10.11646/zootaxa.4317.3.11
publication LSID	lsid:zoobank.org:pub:A2Da6E4B-0Ed3-4518-93Ea-970925711331
DOI	https://doi.org/10.5281/zenodo.6027998
persistent identifier	https://treatment.plazi.org/id/D9616011-B17C-FFDC-FF4C-FBD06B8AFEE4
treatment provided by	Plazi
scientific name	Cycreon Orchymont, 1919
status

Treatment

Cycreon Orchymont, 1919 View in CoL ( Figs. 1–27 View FIGURES 1 – 4 View FIGURES 5 – 12 View FIGURES 13 – 21 View FIGURES 22 – 25 View FIGURES 26 – 27 )

Type species. Cycreon sculpturatus Orchymont, 1919 (by original designation).

Differential diagnosis (following Hansen (1989, 1991), Short & Fikáček (2011, 2013)). The genus belongs to the tribe Megasternini and can be thus distinguished from other Sphaeridiinae by the following characters: head narrowed in front of eyes such that the antennal bases are exposed; clypeus weakly convex in lateral view, its lateral portions without angulate lateral projections; labrum membranous, partly retracted under clypeus; antennal clubs compact; lateral margins of mentum converging anteriorly, without fringe of setae; prothorax with antennal grooves ( Fig. 7 View FIGURES 5 – 12 ); mesoventrite fused with mesanepisterna, i.e. anapleural sutures completely absent; mesoventrite with grooves for reception of procoxae; elytral epipleura are not visible adjacent to abdomen; abdominal ventrite 1 much longer than ventrite 2; maxilla with sucking disc on males ( Fig. 14 View FIGURES 13 – 21 ).

Cycreon is distinguished from the remaining genera of Megasternini by the following combination of characters: antennal grooves of prosternum very small, looking like shallow concavities, defined laterally by a very obsolete ridge situated very close to the notosternal suture ( Fig. 7 View FIGURES 5 – 12 ); mesoventrite very narrow, linearly raised medially ( Figs. 2, 4 View FIGURES 1 – 4 ); abdominal ventrite 1 not carinate medially; male sternite 9 tongue-like ( Fig. 22 View FIGURES 22 – 25 ).

Redescription. 2.6–3.3 mm. Oval, flattened. Body unicolour reddish to yellowish. Upper surface shining, delicately punctate. Ventral surface finely pubescent (except mentum, medial parts of meso- and metaventrite). Clypeus distinctly defined from the frons by lateral branches of epicranial suture, excised on the middle of front edge, finely edged ( Figs. 9 View FIGURES 5 – 12 , 13 View FIGURES 13 – 21 ). Eyes rather convex, rather projecting. Mentum impressed and emarginate anteriorly. Antennae 9-segmented, pedicel much shorter than scape, cupule rather large, club compact, widened distally almost to apex, which appears truncate. Mandibles with two teeth on the apex. Male maxilla with sucking disc. Pronotum almost 2× as wide as long, with rounded anterior and especially posterior corners, lateral margins and angles finely edged ( Figs. 6 View FIGURES 5 – 12 , 16 View FIGURES 13 – 21 ). Surface of pronotum with reduced medial fovea in front of the base. Elytra with 10 moderately strong punctate striae (10th reduced to interrupted row of punctures), interstices flat; humeral tubercles slightly elevated; epipleura evenly narrowed to the level of abdomen. Prosternum bulging in middle, not carinate, with minute antennal grooves ( Fig. 7 View FIGURES 5 – 12 ). Mesoventrite bulging posteromedially, without abruptly raised tablet, simply tectiform, with glabrous median carina, produced into a fine spine posteriorly. Metaventrite with raised, pentagonal and glabrous field; without anterolateral arcuate ridges. Metepisterna rather wide, parallelsided. Legs relatively long: pro- and mesofemora visible protruded for edges of pronotum and elytra. Surface of legs shining, not pubescent. Tarsi densely covered by setae. Tarsomere 1 of middle and hind tarsi longer than tarsomere 2. Ventrite 1 not carinate. Male sternite 9 tongue-like ( Fig. 22 View FIGURES 22 – 25 ).