Abstract: Plastic pollution remains one of the most ubiquitous and menacing ecological threats worldwide. While larger plastics cause concerns when ingested by animals, little is known about the effects of much smaller microplastics, which can be formed by the degradation of plastics by sunlight, abrasion, and tire wear. Microplastics of a few microns in size or less are challenging to remove from the environment and are easily ingested by animals, mainly invertebrates, yet their biological effects are unclear. Microplastics have also been found to alter the gut microbiota of honeybees, collembola, and other soil-dwelling invertebrates resulting in gut dysbiosis. Here we demonstrate the presence of microplastics in artificial containers that make up mosquito larval habitat. Using fluorescent microscopy, we also show the ingestion of 1 um polystyrene microplastic beads by Aedes aegypti and Aedes albopictus larvae. Results suggest there is little effect of ingestion of microplastics on adult emergence rates and adult survivorship of Ae. aegypti and Ae. albopictus. However, we did observe gut damage associated with the ingestion of microplastics. We also demonstrate that ingestion of microplastics results in dysbiosis of the bacterial microbiota but has little impact on the fugal microbiota composition in Ae. aegypti and Ae. albopictus. We discuss these results in the context of potential effects on mosquito fitness and vector competence of arboviruses.
