Where do all the aphids go? A series of thought experiments within the context of area-wide pest management

Aphids are economically important wind-borne crop pests worldwide. Forecasting invasions poses the challenge of modelling both the terrestrial and aerial portions of their life cycle in temporally-variable, spatially-heterogeneous environments. Within the context of area-wide pest management, modelling migrations is particularly problematic. We present a series of thought experiments, using sugarcane aphids (Melanaphis sacchari) as a test case, in which we ponder the relative importance of accurate forecasting of magnitudes of migrations and initial infestations versus accurate forecasting of timing of initial infestations. Our results indicate the latter is more important. Within the context of area-wide pest management programs, this suggests improvement in forecasting models for windborne pests most likely will come from increased emphasis on the aeroecological portion of the pest life cycle.