The effects of Artificial Light at Night on the abundance of Aedes aegypti and Aedes albopictus (Diptera: Culicidae).

Sunlight is one of the most important factors synchronizing the circadian clock of organisms. Natural cycles of light and dark have shaped the rhythms of biological functions throughout the evolutionary time. However, Artificial Light at Night (ALAN) in urban areas has increased significantly in recent decades, interfering with the predictability of the cycling environment and affecting the behavioral and physiological rhythms of organisms living in urban environments. As two urban species, the mosquitoes Aedes aegypti and Ae. albopictus are considered the primary and secondary vectors of several medically important arboviruses, representing major public health issues. Both species are diurnal, with activity peaks at dusk and rest at night. Here we investigated whether ALAN is associated with the number of eggs and larvae of these species. We combined ovitrap collection data of the year 2021, provided by the Municipal Health Department of Rio de Janeiro, with predictive environmental and demographic variables. Among these variables were the intensity of ALAN, estimated as the frequency of pixels of different RGB classes in a night photograph of Rio de Janeiro taken in 2022; the Normalized Difference Vegetation Index (NDVI), the Normalized Difference Water Index (NDWI), the Land Surface Temperature (LST), and the human population density. Our results show that ALAN, in conjunction with higher temperature, is significantly associated with the number of larvae of Ae. aegypti hatched from eggs collected in ovitraps. On the other hand, the number of larvae of Ae. albopictus is explained by the proportion of vegetated area and by temperature.