Effective invertebrate pest management in dryland cropping in southern Australia: the challenge of marginality

Despite research efforts spanning many decades, invertebrate pest control in arable farming systems is still heavily reliant on broad-spectrum pesticides. Yet industry wants to implement Integrated Pest Management (IPM) principles. We suspect that the lack of implementation to date reflects the unpredictable nature of outbreaks of pests and unpredictable profit margins, creating an environment where growers prefer to follow a cautious chemical-based approach. Using southern Australia as a case study, we argue for a new approach where the concept of rigid management strategies is abandoned in favor of landscape changes, host plant resistance, ecological indicators, reliable predictors and emergency intervention strategies. This approach needs to be based on developing more stable crop environments that can limit fundamental niches available for exploitation by sporadic pest populations, and increasing crop resilience to resident herbivores. Fall-back strategies, including broad-spectrum chemical control, may still be required to protect productivity at times when outbreaks of pest populations take place. These are likely to be unavoidable, particularly given emerging climate challenges.Michael A. Nasha, Ary A. Hoffman