Rhambastus Pic, 1939[3] Rhembastus is a genus of leaf beetles in the subfamily Eumolpinae, native to Africa.

Whilst the taxonomy of the genus is disputed, the genus has been suggested as a biological control agent for Bryophyllum delagoense in Australia.

[4] The genus was first identified by the German entomologist Edgar von Harold in 1877 from species in Madagascar, Nyassa and Port Natal.

In 1965, Brian J. Selman reduced the size of the genus by 45 species, transferring them to other genera such as Paraivongius, Massartia and Sarum.

He also suggested that a revision of the Eumolpinae of Madagascar would produce a complete generic separation of the Madagascan and African species.