Biocontrol approaches to cane toad controlAJ Robinson*, A Hyatt#, J Pallister#, N Hamilton* & DT Halliday*
*CSIRO Sustainable Ecosystems, GPO Box 284, Canberra, ACT 2601 and #CSIRO Livestock Industries, Australian Animal Health Laboratory, Private Bag 24, Geelong, Victoria 3220.
Cane toads (Bufo marinus) were introduced into Australia in 1935 to control native beetles that were damaging sugar cane crops. At the time, many other countries were importing the toads for insect control. In Australia they become a pest in their own right mainly due to their toxicity to native predators but also as competitors for food and refuge sites. A means for their control has been on the agenda for a number of decades but to date no effective methods have been found. The most effective means of control would be a biocontrol agent similar to the viruses that were introduced into Australia to control rabbits. Between 1986 and 1996 a determined effort was made to identify cane toad-specific biocontrol agents both in Australia and overseas but no suitable agent was discovered. It is now considered unlikely that such off-the-shelf agents will be found and as a consequence other approaches are being explored. One such approach being carried out at CSIRO is to engineer a virus to interfere with metamorphosis. All amphibians express new proteins during metamorphosis and these are potential “vaccine” antigens or RNAi targets for delivery to tadpoles. The challenge is to ensure that the antigens or RNAi molecules are effective and cane toad specific. Progress toward these goals will be presented.