Effects of larval competition on adult immune traits in Aedes aegypti and Aedes albopictus (Diptera: Culicidae)

Globally, the yellow fever mosquito, Aedes aegypti, and the Asian tiger mosquito, Aedes albopictus (Diptera: Culicidae), are the primary vectors of Dengue virus (DENV). When the ranges of Ae. albopictus and Ae. aegypti overlap, they co-occur in larval habitats, resulting in competition for food resources. The interactions between these species within their larval habitats can alter the innate immune traits of the emerging adult females. In this project, we conducted laboratory experiments to determine the effects of intraspecific and interspecific larval competition on the innate immune traits in Ae. aegypti and Ae. albopictus. Specifically, we measured: the thickness of the basal lamina of the midgut using transmission electron microscopy (TEM), the type and abundance of hemocytes using perfusion and high injection techniques, gene expression in the Toll, IMD, and RNAi Pathways, and antimicrobial peptides, and the thickness of the basal lamina lining the salivary glands using TEM. Previous results have shown that adults which were nutritionally stressed as larvae have modified immune functions including a reduction in hemocyte abundance and a reduction in some immune-related genes. Gaining an understanding of the effects of intraspecific and interspecific larval competition on the immune status of the two main vectors of DENV can improve our understanding of the role of environmental factors in the spatial and temporal  heterogeneity in DENV  transmission and contribute to the design  of novel vector  control strategies.