Oocyclus Sharp, 1882

Short, Andrew E. Z. & García, Mauricio, 2010, A review of the Oocyclus Sharp of Venezuela with description of twelve new species (Coleoptera: Hydrophilidae: Laccobiini), Zootaxa 2635, pp. 1-31 : 4-6

Oocyclus Sharp, 1882

Oocyclus Sharp, 1882: 61 (Type species: Oocyclus brevicornis Sharp, 1882 , by subsequent designation (Knisch 1924)). Beralitra d’Orchymont, 1919: 145 (Type species: Beralitra obscura d’Orchymont, 1919 , by original designation), syn. n.

Diagnosis. Round to elongate oval, slightly convex to nearly hemispherical. Antennae with eight segments. Elytra with systematic punctures, which may or may not be distinct or arranged in rows; often bearing short to long setae; margins not explanate to weakly explanate. Abdomen with five exposed ventrites which are pubescent throughout, although the density of pubescence may vary. Prosternum with or without a pair of spine-like setae or hairs. Process of the mesoventrite usually set with articulated spine-like setae or hairs. Anterolateral corners of pronotum broadly rounded to spinose. Eyes not protruding. Elytral suture raised or not. Males without a modified protarsus (diagnosis modified from Short & Perkins 2004).

As previously mentioned by Short and Perkins (2004), there still remains a substantial number of undescribed taxa in the genus, and the generic concept will continue to be modified to accommodate new character combinations.

Discussion. The genus Beralitra d’Orchymont, 1919 up to now consists of two southern Neotropical species, one each from Bolivia and Argentina ( Oliva 1996, Hansen 1999). Within the Oocyclus -group of genera, Beralitra is traditionally distinguished by possessing a raised elytral sutural interval, and explanate elytral margins ( Oliva 1996, Hansen 1991). When Beralitra was first described (and indeed, until very recently), only a handful of Oocyclus species were known and the distinction between genera was fairly distinct. As dozens of Oocyclus (and other Oocyclus -group species) were described in the last six years, the morphological differences between the genera have gradually shrunk as new morphological combinations and intermediates were discovered.

Here, several Oocyclus species are described (e.g. O. meridensis , O. galbus ) that possess the hitherto ‘diagnostic’ characters for Beralitra , as well as species that have weakly explanate margins, and/or weekly raised intervals. Consequently, as there are no longer any known synapomorphies that would separate Beralitra from Oocyclus , we place them in synonymy. We examined the type specimen of B. obscurus d’Orchymont, 1919 and unidentified Beralitra specimens from Paraguay. This nomenclatural act results in two new combinations: Oocyclus obscurus (d’Orchymont) and Oocyclus iguazu ( Oliva, 1996) .