Integrated modelling of the life cycle and aeroecology of wind-borne pests in temporally-variable spatially-heterogeneous environment

Integrating population ecology and aeroecology is important for understanding dispersal dynamics of pest insects that depend on aerial habitats. Sugarcane aphid (Melanaphis sacchari) is an economic pest of sorghum in Asia, Africa, Australia, and South America and recently invaded North America, affecting over 90% of the continent’s sorghum production. Long-distance, wind-aided dispersal together with the ability to overwinter in the southernmost sorghum-producing areas appear responsible for their geographic spread in North America. We developed a spatially-explicit, individual-based, stochastic model that integrates the life cycle and aeroecology of sugarcane aphids to forecast regional infestations of sorghum fields. We parameterized and calibrated the model to represent environmental conditions and sorghum phenologies of the southern to central Great Plains of the USA where sorghum is cultivated. We validated the model by comparing simulated spatial-temporal patterns of aphid infestations to georeferenced field data on infestations collected as part of an extensive field project. We assessed potential usefulness of the model by analysing regional patterns of aphid infestations on sorghum simulated under climatic conditions recorded in the southern to central Great Plains in 2017.