Exploring the resting habits of invasive Aedes albopictus mosquitoes in Southern France

Aedes albopictus, an invasive mosquito and vector of arboviruses such as dengue, chikungunya, and Zika, has rapidly expanded across mainland France. While its breeding and host-seeking behaviors are well studied, little is known about its adult resting habits in temperate urban environments. We conducted a field study in Murviel-lès-Montpellier, Southern France, using oviposition traps and aspiration from sentinel resting sites to assess adult mosquito dynamics. Between July and October 2023, 1293 capture sessions yielded 2237 adults and 172,014 eggs. We analyzed mosquito physiological status, vegetation structure (Plant Area Index), and microclimatic conditions. Resting site type, vegetation density, temperature, and humidity significantly influenced mosquito abundance and sex ratio. Underground cable chambers hosted mainly sexually immature adults, while sexually mature mosquitoes were more abundant in dense vegetation, especially cane of Provence thickets. Our results highlight how intrinsic (sex, physiological status) and extrinsic (microhabitat, weather) factors shape resting site selection, informing targeted vector surveillance and control in urban settings.