Phytotelmata ecology influences coexistence of Aedes aegypti and Aedes albopictus in California

Water-holding ornamental bromeliads are a commonly utilized larval habitat for the invasive Aedes mosquitoes that are spreading across the United States. While they are unique habitats in many ways, bromeliads also serve as a model for cryptic and ecologically complex breeding sites for invasion ecology and vector control. While these plants have notoriety for contributing to vector populations, little is known about their role in mediating population dynamics between species, especially in areas like California which lack any bromeliad phytotelmata specialists. Recent studies have also shown that current larvicidal strategies are less effective in these plants when not addressed directly, making bromeliads a refuge both from competition with native species, and from vector control strategies. To gauge differences in use, bromeliads were placed in the field where all species were found. Oviposition and larval presence of the different species in these plants was compared to nearby conventional traps. Ecological effects were then studied by examining the influence of bromeliad microhabitats on larval development in Aedes aegypti and Aedes albopictus, in isolation and in competition with each other. These were compared to similarly sized habitats in artificial containers. Lab assays examining oviposition behavior in plants and containers were also carried out to verify field findings. Current targeting of more conventional habitats may be elevating the importance of the differences found, and concentrating their effects on vector populations in California, warranting further study to safeguard public health and inform control efforts.