Locust swarms pose a major threat to agriculture, notably in northern
Africa, the Middle East, and Australia. In the early stages of
aggregation, juvenile locusts form hopper bands. These are coordinated
groups that march in columnar structures that are often kilometers
long and may contain millions of individuals. In later stages locusts
swarms become airborne and can decimate crops over hundreds of
kilometers potentially leading to famine and widespread ecological
disruption.
In this talk I will describe two strategies for modeling locust
swarms. Agent-based models (ABMs) yield ordinary differential
equations for groups of interacting individuals and are easy to
implement but challenging to analyze. Homogenizing these models
replaces the individuals with population densities that are governed
by partial differential equations (PDEs) which are more difficult to
simulate but which can be analyzed via dynamical system methods. I
will then discuss the challenges of informing models with experimental
observations and report on an ongoing study that uses motion tracking
of tens of thousands of locusts in the field to shed light on how
behavior is influenced by social interactions.
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