Abstract: Notes on the biology of three Australian dermestid beetles (Coleoptera: Dermestidae) are provided here. Predation upon the egg-case (and its contents) of the common Australian praying mantis, Archimantis latistyla (Serv.)(Mantidae: Mantodea) by the introduced Dermestes maculatus DeGeer is recorded and discussed. Thaumoglossa nigricans Macleay is also recorded from a mantid egg-case. Some adult food plants of the introduced Anthrenus verbasci L. are recorded from the plant families Asteraceae, Brassicaceae and Myrtaceae.