Hitchhiking Microplastics Through Mosquitoes as Unseen Vehicles of Terrestrial and Aerial Transfer: Experimental Evidence

BackgroundMicroplastic (MP) pollution is an emerging environmental concern that extends beyond aquatic systems into terrestrial food webs. The mosquito Anopheles stephensi, a major malaria vector in Asia and the Middle East, undergoes complete metamorphosis and offers a useful model to examine cross-stage MP transfer. However, the physiological consequences of such exposure remain poorly understood. MethodsFluorescent polystyrene microplastics (1 {micro}m) were administered at six concentrations (0-300 mg L-1) under controlled laboratory conditions. Larvae were reared on standard fish pellets, and adults were maintained on a 10% sucrose solution. Fluorescence microscopy tracked MP ingestion and transfer across life stages. Larval weight, developmental timing, and survival were analyzed using ANOVA and Chi-square tests. ResultsOntogenic transfer of microplastics was confirmed from larvae to pupae (100%) and adults (94%). Increasing MP concentrations accelerated development by 1-2 days but significantly reduced survival, with mortality rising from 12% in controls to 64% at 300 mg L-1. Body weight declined consistently in a dose-dependent manner (p < 0.001). ConclusionThis study provides the first experimental evidence of ontogenic MP transfer in An. stephensi. Microplastic exposure alters development and survival, potentially affecting mosquito population dynamics and vectorial capacity, highlighting the need to incorporate MP pollution into vector ecology models.