Environmental heterogeneity drives tsetse fly population dynamics

A spatially and temporally heterogeneous environment may lead to unexpected population dynamics, and knowledge still is needed on which of the local environment properties favour population maintenance at larger scale. As regards pathogen vectors, such as tsetse flies transmitting human and animal African trypanosomosis, such a knowledge is crucial for proposing relevant management strategy. We developed an original mechanistic spatio-temporal model of tsetse fly population dynamics, accounting for combined effects of spatial complexity, density-dependence, and temperature on the age-structured population, and parametrized with field and laboratory data. We confirmed the strong impact of temperature and adult mortality on tsetse populations. We showed that patches with the lowest mean temperatures and lowest variations act as refuges when adult mortality is homogeneously increased. Our results highlighted the importance of baseline data collection to characterize the targeted ecosystem before any control measure is implemented to maximize its efficiency.