ECONOMICS OF INSECTICIDE RESISTANCE MANAGEMENT IN HELIOTHIS-ARMIGERA (LEPIDOPTERA, NOCTUIDAE) IN AUSTRALIA

An insecticide resistance management (IRM) strategy for Heliothis armigera (Hubner) has been used in Australia since 1983. An ex post evaluation is difficult because we are unsure what the outcome would have been had the IRM not been introduced. We compared the actual outcome with the projected outcome of various scenarios that captured the best available estimates concerning what would have happened without IRM or with alternative IRM strategies. We also compared two variants of the economic surplus method for evaluating the investment in IRM. Our analysis suggests that the economic benefits of the introduction of IRM have been substantial and that an IRM strategy should be designed to exploit insecticide susceptibility at an optimal rate. In Australia, the highest economic return was realized by the permitted use of three pyrethroid sprays per season. The low cost of implementing and maintaining the IRM in relation to its high rate of economic return indicated an excellent opportunity for increased investment in research into alternative IRM approaches. IRM is a social technology. The IRM in Australia is unusual because so many factors worked in its favor. The transfer of IRM technology to different socioeconomic situations might be more difficult.