Linking abiotic conditions to mosquito assemblage structure in bromeliads

Bromeliads provide a unique habitat for many insect species, including immature forms of mosquitoes. This study investigates the effect of abiotic factors, specifically temperature, rainfall, water volume, and physicochemical parameters, on the occurrence and abundance of mosquitoes developing in bromeliads within the Brazilian Atlantic Forest. Larval samples and abiotic parameters were collected from nine bromeliads between 2015 and 2017 in a forest remnant in São Paulo, Brazil. Relationships between variables were tested using generalized linear mixed-effects models and structural equation modeling (Piecewise SEM). Results indicate that rainfall and temperature influence the water volume of bromeliad tanks, which in turn affect physicochemical parameters, particularly pH. These variations affect the richness, abundance, and occurrence of mosquito species, including the vector of malaria parasites, Anopheles cruzii Dyar & Knab, 1908. Piecewise SEM analysis indicated that the data were satisfactorily fitted for the models tested: species richness (Fisher's C = 13.5, df = 12, p = 0.33, R² = 0.13), total abundance (Fisher's C = 10, df = 8, p = 0.26, R² = 0.63), and An. cruzii presence (Fisher's C = 4.6, df = 8, p = 0.8, R² = 0.32). The study highlights a cascade effect where abiotic factors alter the microhabitat conditions, thereby affecting mosquito populations. Understanding these interactions is crucial for predicting the impacts of climate change on mosquito-borne diseases in tropical regions.