1. Department of Agriculture and Fisheries, GPO Box 267, Brisbane, Queensland 4001, Australia.
2. Department of Biology, Trinity Western University, Langley, British Columbia, Canada V2Y 1Y1.
3. Agricultural Environment and Resource Research Institute, Yunnan Academy of Agricultural Sciences, Kunming, Yunnan 650205, China.
4. Graham Centre, Charles Sturt University, Wagga Wagga, New South Wales 2678, Australia.