Open Access

Erinn P. Fagan-Jeffries, Andrew D. Austin

• The genus Cotesia Cameron, 1891 is one of the most diverse of the Microgastrinae, a subfamily of wasps that are exclusively endoparasitic on lepidopteran larvae. Species of Cotesia are widely utilised as biological control agents across the world. In Australia, there are currently 10 confirmed native species as well as four species introduced for the management of lepidopteran pests. The genus is morphologically conserved and has not been studied in the Australasian region for many decades. In this study, we use both comparative morphology and sequence data from the COI gene to delineate species, and in so doing describe seven new species from Australia: C. lasallei sp. nov., C. medusae sp. nov., C. ocellata sp. nov., C. reidarum sp. nov., C. scripta sp. nov., C. tjapekki sp. nov. and C. wonboynensis sp. nov., raising the number of species of Cotesia formally recorded in Australia to 21. We also provide updated descriptions of the previously described native species, diagnoses for the introduced species and a key to all currently described species found on the continent and from Papua New Guinea. This study treats only a fraction of the likely diversity of Cotesia, but provides a solid framework for future work.