This is what Epler calls "cf. granarius" from his Water Beetle Manual. Examination of both the external features and the dissected genitalia confirms the identification. This species is highly variable and your specimen shows both long elytral plicae (the sublateral grooves on the elytral bases) relative to the pronotal plicae and evenly rounded elytral margins, both of which do not fit Larson's description of "Uvarus granarius" sensu stricto, which has elytral and pronotal plicae subequal in length and straight posthumeral elytral margins. Because of these differences, the species may in reality be a species composite (consisting of more than 1 species). I will place this in the species page for now until the species (and the genus) gets revised and new names are assigned. The genus overall is in a taxonomic mess anyway and therefore a new revision of the group is needed.

can't decide on which one from the images..something is strange about this one.