Gambusia holbrooki (aka.: topminnow, mosquitofish, plague minnow) is a successful and aggressive invader of Australia’s waterways, and is now considered a serious pest. Large aquatic insect taxa native to south-eastern Australia have the potential to provide some measure of G. holbrooki control through predation. Such predators may be able to reduce the numbers of G. holbrooki present in wetlands and therefore reduce the impact of G. holbrooki on wetland ecosystems. Each of these species of aquatic insects was evaluated for their potential as a biological control for the G. holbrooki. Several taxa of Nepidae, Aeshnidae and Dytiscidae larvae were tested in a laboratory environment. Only the Aeshnidae nymphs (Adversaeshna brevistyla) were successful and persistent predators of G. holbrooki up to 30 mm in size. Adversaeshna brevistyla larvae were found to  eat G. holbrooki in aquaria, and may be a useful biological control agent in urban waterways.