Microplastic ingestion alters the composition of Aedes mosquito species microbiota

Abstract: Plastic pollution remains one of the most ubiquitous and menacing ecological threats worldwide. Though larger plastics have been known to impact the biology of vertebrates, little is known about the effects of much smaller microplastics when ingested by invertebrates. Microplastics of few microns or less are formed by UV light and abrasion degrading larger pieces of plastic. Unfortunately, microplastics are difficult to remove from the environment and are easily ingested by animals, particularly invertebrates such as insects. In many insect groups the effect of ingestion of microplastics remains unclear. To date, no studies have examined the effects of microplastics on the microbiome and physiology of container inhabiting mosquitoes from the genus Aedes. The goal of this study was to examine if varying concentrations and sizes of microplastics will have an impact on the composition of the microbiota of Aedes mosquitoes and impact adult emergence rates. Fluorescent polystyrene beads of 1 and 0.03 µm diameter were fed to Aedes mosquitoes as larvae at varying concentrations, and 16s and ITS2 high through Illumina sequencing was used to identify changes in bacterial and fungal microbiome. Understanding the effects of microplastics on microbiota composition will be crucial for predicting and effectively mitigating the effects of microplastics exposure in mosquitoes and other insects. The results of this study are discussed in relation to the impact of microbiome changes on vector competence of arboviruses.