The papers submitted in support of my application for a Doctor of Science represent the outcome of a major research program begun in 1972. They contain a critical review of the Australian parasitic wasp fauna of the superfamily Chalcidoidea and are centred around the voluminous and confused research of A. A. Girault between the years 1911-1940. The research submitted is a significant contribution to the taxonomy of the Chalcidoidea not only within Australia but also internationally and has been supported by substantial grants from the Australian Biological Resources Study and the US/Australia Co-operative Science Program. The work has bearing on applied as well as pure science. Boucek (1988), whose revision of the Australasian Chalcidoidea was founded on my critical review of Girault's work states, The Australian fauna of chalcids ... is fascinating, strange and in many respects beautiful, but this was not why the present work was done. The main reason was a more practical one-to get rid of taxonomic and nomenclatura] chaos and, thereby facilitate studies of all kinds. An improvement of taxonomic knowledge is greatly needed especially for projects connected with control of injurious insects and also open those groups for studies of a wide spectrum of biological aspects, including fauna! studies, studies of host-parasite relations, ecological, ethological (behaviour) studies and so on. The papers may be grouped as follows: I) Critical review of Girault's work including Girault's Privately printed papers; 2) Taxonomy and biology of Melittobia (Eulophidae); and 3) Review of Girault's Australian encyrtid genera. Of these Girault's Privately Printed Papers and the Review of Girault's Australian encyrtid genera are under joint authorship. My contribution to these papers is outlined under the discussion of each. The three papers on the taxonomy and biology of Melittobia are published versions of my MSc thesis successfully submitted to the University of Queensland in 1982.