Periodic Reporting for period 2 - MOVE (Modelling to Optimize Vector Elimination: Destabilising mosquito populations) Reporting period: 2021-08-01 to 2023-01-31 Summary of the context and overall objectives of the project Vector control is the ubiquitous strategy against many of the most important vector-borne diseases such as malaria and dengue. Its sustainability and eventual success relies on our ability to understand how vector population dynamics and behaviour respond to those control interventions and human-mediated environmental changes. The project MOVE was designed to investigate the role of ecological dynamics in regulating mosquito populations occurring across three ecological scales; within-population, between-populations and within community, and how interventions could harness these processes to accelerate vector elimination. We will do this by developing and applying contemporary ecological models to a range of unique longitudinal entomological surveillance data sets, collected over decades as part of malaria surveillance and control programmes by our partners working in several African countries. Work performed from the beginning of the project to the end of the period covered by the report and main results achieved so far We have the team in place and collated a range of unique longitudinal entomological and genomic data sets collected over decades as part of malaria surveillance and control programmes by our partners working in several African countries. Preliminary within-population simulation models have highlighted important trade-offs between density-dependence and allee effects in mosquito populations. These suggest that if we can identify a threshold when the Allee effects become active, it is possible to accelerate elimination of mosquito populations even when density-dependence is present. Between populations, preliminary results from genetic data indicate that there is population structuring in malaria mosquito population but whether this is a consequence of interventions or ecology requires further investigations. This ongoing work has been presented at various meetings and conferences. Progress beyond the state of the art and expected potential impact (including the socio-economic impact and the wider societal implications of the project so far) We expect that by the end of the project we will a deep understanding of how vector populations are regulated at different ecological scales and how vector control interventions impact those populations. We also expect to have a general framework to assess other vector populations. Specifically for improving vector control, examples of expected results within populations are the identification of thresholds for tipping into extinction vs rebound of vector populations, between populations we expect to determine how populations are structured over space and predict the optimal distribution of effort through space and time, and between species we expect to determine if a reduction the target species leads to higher or lower community disease transmission capacity. Broadly, we expect to identify unanticipated negative and positive effects of mosquito population suppression arising from a broad range of interventions.