The species is known from a single malespecimencollected in 1959. The body is 5.5 mm. long and the wing is 6 mm.. It is distinguished from the similar species P. cinereofasciatus, P. formosanus, and P. nigroscutellatus by having dark brown to black postpronotal lobes with yellow margins.
Part of the label on the holotype says: "British N. Borneo, Tenompok", which is the type locality from which the name is derived. The latinsuffix "-ensis" means "pertaining to" or "originating in".