Behavioural Epidemiology and Evolution of Plant Pathogens – BEEP

Behavioural epidemiology studies the interaction between human behaviour and the spread of infectious diseases. Plant pathogens and their insect vectors are among the main threats to global food security. The methods used to control plant pathogens and their vectors must be ecologically-friendly and sustainable. To date, the few models that couple grower behaviour with plant disease epidemics do not address pathogen evolution. However, grower decisions impose new selection pressures on pathogens, which evolve and adapt to control methods. Grower decisions may concern several control methods including the use of disease-resistant varieties, roguing (i.e., removing) infected hosts, and the use of biocontrol agents against pathogens or their insect vectors. Our biological models include the Citrus greening disease (caused by vector-borne bacteria), and nematodes of potato and tomato. The objective of this project is to develop a theory of behavioural epidemiology specific to plant health, with an evolutionary perspective. More specifically, we will explore the key mechanisms allowing the adoption (or not) of control methods in sufficient proportion to maintain disease incidence under an acceptable level, taking pathogen evolution into account. Such control methods are often expensive, and we aim at assessing to what extent subsidising them would stabilise their use in order to maximise plant health in the long-run. The consortium gathered around this project brings together expertise in plant disease epidemiology, mathematics, computer sciences, and economics. The interdisciplinary nature of the project will lead to original research in the field of plant disease epidemiology and evolution. From an applied perspective, this project will help design policies to control plant diseases that consider the dynamic behaviour of growers as well as pathogen evolution. This research aims to develop plant protection methods respectful of people and their environment.