Molecular evidence of three Sclerotia species indicates that they form a natural group that is distinct from other genera.

Although Sclerotia species are no exception, they are united by distinctive internal features such as the eponymous three sclerites that surround the aedeagal sheath in the reproductive organ of the males, a unique feature within the subfamily.

These sclerites are attachement sites for muscles, but their exact function in reproduction is unclear, and the mating process has not yet been observed.

Sclerotia is furthermore characterised by parallel and longitudinal rows of punctures over most of the elytra (forewings).

[1] The larvae are known of three Sclerotia species; these are aquatic and swim on their backs just below the water surface.