_Natural host._--_Robshelfordia longiuscula_ or _Robshelfordia circumducta_, Australia Capital Territory (Riek, 1955). =Rhipidioides mollis= Riek _Natural host._--_Robshelfordia longiuscula_ or _Robshelfordia circumducta_, Australia Capital Territory (Riek, 1955). =Rhipidioides rubricatus= Riek _Natural host._--_Choristima_ sp. and _Choristimodes_ sp., Australia Capital Territory (Riek, 1955). =Riekella australis= (Riek) _Synonymy._--_Nephrites australis_ Riek [Selander, 1957]. _Natural host._--_Cutilia_ sp., Australia Capital Territory (Riek, 1955): Two females emerged from one host. =Riekella nitidioides= Selander _Synonymy._--_Nephrites nitidus_ of Riek not Shuckard [Selander, 1957]. _Natural host._--_Platyzosteria_ sp., Tasmania (Riek, 1955). =Riekella= sp. _Synonymy._--_Nephrites_ sp. [Selander, 1957]. _Natural host._--_Platyzosteria castanea_, Australia Capital Territory (Riek, 1955). _Biology of Australian Ripidiini._--The Australian species of Ripidiini are parasites of apparently endemic, ground-dwelling species of cockroaches. There is some correlation between host subfamily and parasite genus: _Riekella_ spp. [= _Nephrites_] have only been bred from Blattinae. _Rhipidioides_ spp. occur only in the closely related Ectobiinae and Pseudomopinae. _Neonephrites_ and _Neorhipidius_ also occur in the Pseudomopinae. _Paranephrites_ occurs in the Panchlorinae. There is some evidence that the parasitized cockroaches migrate onto trees when the larval parasite is mature, as pupae have only been found on the trunks of eucalyptus trees. In all species the larva leaves the host dorsally through an intersegmental membrane. The host continues to live for a few days after the parasite emerges. The larva attaches itself to bark on the tree trunk by a few strands of silk before pupating. The larviform, wingless female remains near the pupal skin and is sought out by the winged male. The eggs are laid in a mass around the pupal skin (Riek, 1955). =Ripidius[5] boissyi= Abeille Balduf (1935) lists _Ripidius boissyi_ as parasitic on nymphs of _Ectobius pallidus_ giving Abeille de Perrin (1909) as a source for this information. However, Abeille de Perrin simply presumed that _R. boissyi_ parasitized _E. pallidus_ because he collected this cockroach in the same habitat as the beetle. Abeille de Perrin suggested that the species of the genus _Ripidius_ lived in the bodies of cockroaches, but there are no rearing records, as far as we know, of _R. boissyi_ from cockroach hosts. =Ripidius denisi= Chobaut Chobaut (1919), in France, collected both _R. denisi_ and _Ectobius pallidus_ when beating an oak tree. Because of the known association of other species of _Ripidius_ with cockroaches, he presumed that this beetle was parasitic on _E. pallidus_, a cockroach common in this beetle's habitat. =Ripidius pectinicornis= Thunberg _Synonymy._--_Symbius blattarum_ Sundevall [Leng, 1920].