Workpackage 4

This task will estimate determinants of the spatio-temporal dynamics of pest and natural enemy populations as functions of landscape structure and floristic composition in fields. It will focus on the most important pests in cereal, seed grape and apple crops and a few predators/parasitoids couples with these pests according to task 3 conclusions. It will mainly use population genetic concepts to investigate the effects of the environmental factors previously determined in tasks 1 and 2 on population dynamics. Subtask 4.1 will analyze population genetic structure in these biological systems. Subtask 4.2 will use mark-release-recapture experiments and additional spatio-temporal records of abundance within fields and their edges to better understand movements between crops and semi-natural habitats. Subtask 4.3 will develop mechanistic and Bayesian approaches to estimate population dynamics (notably dispersal and population size demographic parameters) for few important species that interact in selected agronomic systems. Overall, task 4, will provide qualitative and quantitative estimates of population demography, which will be used to parameterize population dynamic models in task 5.