Ecology and management of migratory 'Helicoverpa punctigera' in Australia

Introduction: The native budworm, 'Helicoverpa punctigera' (Wallengren), is a serious pest of cotton and many other field crops in Australia. Daisies and native legumes are important sources of 'H. punctigera' moths in the semi-arid regions of inland Australia. Early studies on the ecology of 'H. punctigera' in inland Australia in the mid-1980's to mid-90's suggested that moths emerging in early spring from the inland migrate on strong north-westerly winds that accompany the passage of cold fronts, towards the cropping areas in the south and east of the continent. This spring migration has been considered to be the key ecological reason why this species has not developed resistance to insecticides. However, recent resistance monitoring in transgenic cotton demonstrated temporary increases in the frequency of alleles conferring resistance to the Cry2Ab toxin in 'H. punctigera'. Methods: Since 2009 we continued the long-term monitoring of 'H. punctigera' populations in south-western Queensland, and recently, in inland South Australia, through a network of pheromone traps and host plant and larval surveys, to determine whether the spring migration system in 'H. punctigera' has changed and what factors might have contributed to this change. Results/Conclusion: An overview of the population dynamics of 'H. punctigera' in inland Australia will be presented. Our pheromone trapping data for non-cropping regions in inland Australia contribute to a forecasting system for 'H. punctigera' migration to south-eastern Australia during spring, which is initiated by CESAR Australia in collaboration with other organisations providing data for cropping regions in eastern Australia.