The role of biological control agents in an IWM program for Chrysanthemoides monilifera subsp. rotundata (bitou bush).

Bitou bush, Chrysanthemoides monilifera subspecies rotundata, is a native of South Africa, which was used extensively in Australia as a sand-stabilising plant and for revegetation of coastal areas mined for mineral sands. It has now become a serious environmental weed in eastern Australia, primarily of conservation areas, where it significantly reduces biodiversity. Since 1989, six species of insects have been released on bitou bush, four of which have established. These are having varied impacts on bitou bush with bitou tip moth, Comostolopsis germana, and bitou seed fly, Mesoclanis polana, being the most successful. An integrated weed management approach appears to be the best option for long-term sustainable control of bitou bush. This paper discusses the use of biological control agents in combination with other control options such as strategic herbicide applications, fire, physical removal and revegetation techniques.