Dynamic simulation modelling of locust outbreaks

Abstract

Much about the life history and biology of the Brown Locust, Locustana pardalina (Walker), is known and documented; little is known of how locust populations change and move, owing to their occurrence in sparsely inhabited regions of southern Africa. With a view to understanding the mechanisms driving population fluctuations, a model for simulating plague events was developed for the Mathworks Matlab™ interpreter. A previously developed model, applying rules that determine the transitions between the stages of the locust life-cycle, contingent on daily rainfall and temperature records, was enhanced by migration probability functions based on the distance between stations, wind speed, locust flight duration and wind heading. It was hypothesised that incorporating the phenomenon of wind-facilitated migration into the basic model would increase the accuracy of predictiors. The inclusion of migration tracking routines manifests itself in improvements in the simulation of outbreak events with respect to timing.