Networks of habitat patches in tsetse fly control: implications of metapopulation structure on assessing local extinction probability

The tsetse fly complex (Glossina spp.) is widely recognized as a key contributor to the African continent’s continuing struggle to emerge from deep economic, social and political problems. Control efforts for the fly have resulted in both successes and failures and good decision-making tools are imperative in tsetse control programs. Because of the cost and complexity of these efforts, informed evaluations guided by mathematical models have been critical in making decisions for tsetse control. Most of these assessments have relied upon a small cadre of mathematical models. Most of these models, however, have not adequately addressed the complex spatial context in which tsetse flies are found. In this paper I use spatial network structure combined with classic metapopulation modeling in order to explore how extinction probabilities differ from simpler formulations that do not take into account spatial structure. The model shows how that as network connectivity increases, metapopulation persistence also increases, and the probability of extinction decreases. The implications that these model findings have for tsetse control and program management are discussed, especially as they relate to Sterile Insect Technique (SIT).