Predicting the distribution and population structure of Aedes aegypti in response to microgeographic variation on the Caribbean nation of St. Kitts and Nevis

Understanding how biotic, abiotic, and anthropogenic variables affect larval and adult mosquito habitat is crucial for predicting vector borne disease transmission. Fine-scale heterogeneity in the quality and quantity of mosquito habitats can depend on vegetation refugia for adults, detritus inputs and moisture for larval habitats, and competitor or biocontrol species that determine larval survival. Here, we surveyed larval and adult mosquitoes on the Caribbean nation of St. Kitts and Nevis in Sep-Oct2019, to determine the relative abundance and distribution of the arbovirus vector Aedes aegypti in relation to human land use and other biotic and abiotic variables. Ae. aegypti is of public health interest as it locally vectors Dengue virus. Findings showed widespread distribution of Ae. aegpyti across habitat types (urban, agriculture, secondary forest, rainforest, and mangrove). For future work, we propose a combination of field trapping and genetic assays (using ddRAD sequencing) to test how mosquito population structure covaries with microgeographic variables, such as temperature, moisture, vegetation, and human land use metrics. We predict that population structuring will depend most strongly on barriers to movement, habitat suitability (which determines adult and larval abundance), and human mediated dispersal. Understanding patterns of gene flow in this system can inform vector control efforts and help model the dynamics of Ae. aegypti subpopulations in heterogeneous landscapes.