PROJECT OBJECTIVES: * To use standard bioassay techniques to establish the particular resistance I susceptibility profiles of Australian native and B-biotype B. tabaci. Insecticide tested, will be organophosphates, carbamates, pyretbroids, newer pyrethroids, cyclodienes, novel control agents. Evaluation the mechanisms of resistance to organophosphates, carbamates and pyrethroids in Bbiotype B. tabaci. * Assess the applicability of rapid biochemical resistance monitoring techniques to B. tabaci. * To investigate the relationship between B-biotype characteristics (silverleaf induction and B esterase bands) and insecticide resistance in B-biotype B. tabaci, will be investigated. * Assessment of the potential of B- type B. tabaci to interbreed with and thus spread insecticide resistance into native B. tabaci. * To investigate the relationship between "resistance status" and field control of resistant B. tabaci. * Resistance management strategies will be devised and tested in the field and the laboratory