Non-additive effects of leaf resources on mosquito competition and production in container habitats

Nutrient diversity is critical to fitness in many species, and may determine the coexistence of competitive species and the function of ecosystems. In this study, we examine the importance of leaf species and combinations of leaves, which commonly form the detritus base in aquatic container habitats. Specifically, we examined how leaf species affect competition between two container inhabiting mosquito larvae, Aedes aegypti and Aedes albopictus , that co-occur in many parts of the world. We tested the hypotheses that leaf species affects the outcome of interspecific competition between these mosquito species, and that combinations of leaf species affect both competition and the production of mosquito biomass, a measure of ecosystem function in container habitats. We find partial support for our first hypothesis that leaf species can impact competition, and strong support that combinations of leaves impact density dependent competitive interactions and ecosystem function synergistically. We conclude that in this container system combinations of leaves increase mosquito production non-additively, and leaf combination is more important than initial larval density or type of competition (inter-or intraspecific) in determining productivity.