Redesigning sugarcane for resistance to Australian canegrubs: a potential IPM component

Abstract

Current management options to minimize the impact of canegrubs (larvae of melolonthine scarabs) on Australian sugarcane are heavily dependent on the use of synthetic insecticides. In developing a successful integrated pest management (IPM) programme for canegrubs, control options must be broadened. Plant resistance offers the potential for an easily deliverable and environmentally acceptable management option. Previous anecdotal reports suggest that Australian cultivars vary in their resistance to canegrubs. Many sugarcane clones (Saccharum spp. complex hybrids) have been screened and our studies have shown that there is variability in resistance through the reduction of the amount of tops, roots and stubble and in their effects on canegrub development and survival. Proteinase inhibitors, lectins and avidin have been identified as having activity against Australian canegrubs and are being introduced into the sugarcane genome. Toxins from Bacillus thuringiensis have shown little potential and are not being used further. We present a rationale for using resistant plants as a control option and for the incorporation of plant resistance into the breeding programme. Projected research will screen more sugarcane clones for resistance, study the nature of inheritance, identify chemical mechanisms involved in antibiotic effects, screen further antimetabolites for possible incorporation into the genome, prove the potential resistance of genetically engineered plants and incorporate plant resistance into an IPM programme for canegrubs.