Predicting Long-Distance Migration of Insect Pests in Eastern Australia

In eastern Australia several economically important insect species undertake long-distance migrations. These migrations can result m the sudden and unexpected arrival of significant numbers of insects in agricultural districts. The semi-arid inland of Queensland, New South Wales and South Australia is an important source area for migrations of several insect pests: the noctuids, 'Mythimna convecta' (McDonald et al. 1990), 'Helicoverpa punctigera' and 'H. armigera' (Gregg et al. 1993), and the Australian plague locust 'Chortoicetes terminifera' (Clark et al. 1969). This paper reports research aimed at forecasting migrations of Helicoverpa spp and C. terminifera. Accurate forecasts of long distance migration cannot be made unless the location, size and age structure of the source populations are known. These are difficult to determine for inland Australia where the remoteness, sparse human population, and low intensity land use mean that source populations, even if noticed, often go unreported.