Ecology of Cirsium vulgare and Silybum marianum in relation to biological control
E. Bruzzese, Keith Turnbull Research Institute, Co-operative Research Centre for Weed Management Systems, PO Box 48, Frankston, Victoria 3199, Australia.
Summary
Spear thistle (Cirsium vulgare) and variegated thistle (Silybum marianum) are two of the most widespread thistles which infest pastures in temperate southern Australia. A biological control program targeting these thistles was commenced in 1985. No specific ecological studies of these thistles and their predators in the area of origin aimed at the selection of insects for release in Australia, have been carried out. Insects have been released in Australia, based on data from biocontrol programs against these thistles elsewhere in the world. This paper reviews the literature on ecological studies of these thistles and the effects of their predators. Additional studies from Victoria are summarized. Progress towards the classical biological control of these weeds in Australia is outlined and conclusions are drawn on the chances of success using the agents currently available.
Plant Protection Quarterly (1996) 11 (Supplement 2) 245-249.