Abstract Budginmaya eulae gen. et sp. nov. is described from the nest of a Camponotus terebrans (Lowne) ant from Western Australia. The species shows adaptations for subterranean life, including reduction in the tegmina, wings and eyes and increased hairiness around the head, body, tegmina and legs. This is the first record of an Australian planthopper (Fulgoromorpha) cohabiting with ants and the first record of an inquiline species in the family Flatidae. Furthermore, this flatid is most likely a short-range endemic species currently restricted to Bandalup Hill