Microplastics on the menu; exploring interactions between two mosquitoes species and microplastics

Microplastic pollution exposes organisms to severe alterations in their life history traits. Once ingested, microplastics can fragment further, facilitating their dispersal in ecosystems. However, the risk of ingestion and the capacity for fragmentation vary among organisms based on their ecology. In this study, we used two mosquito species with different larval ecologies: Anopheles gambiae, which filters particles at the surface, and Aedes albopictus, which grazes on biofilm on submerged surfaces. We exposed them to various concentrations, sizes, and densities of microplastics (polystyrene, which sinks, and polyethylene, which floats). We assessed the probability of ingestion, the quantities ingested, and the impacts on survival, sex ratio and individual size. We also investigated whether these larvae could physically or chemically alter the microplastics during digestion. The risk of microplastic ingestion primarily depends on particle size rather than larval ecology. Only the survival of An. gambiae adults exposed during larval development was affected by microplastics, and this was only at the highest concentration. Microplastics had no impact on other measured traits. No physical or chemical alteration of the microplastics was detected following ingestion.