The impact of microplastics on insect physiology and the indication of hormesis

Insects play an important role in the ecosystem. In recent years, the global population and species of insects have shown a dramatic decline. Microplastic pollution has attracted widespread attention. Therefore, this paper reviews the progress of research on the physiological effects of microplastics on insects in recent years. The data show that the effects of microplastics on insect physiology are dose-dependent, with multiple factors involved, including the different physicochemical properties of microplastics and the physiological characteristics of the insects. Microplastics can negatively affect the survival, reproduction, development, and gut microbiota of insects. High concentration and small size are normally associated with high toxicity. Available studies also show the existence of the threshold and hormesis response in the action of microplastics, i.e. low doses are beneficial to insects. These indicate that it is important not only to focus on the toxicity of high doses of microplastics, but also to have a comprehensive understanding of the effects of microplastics on insects from a hormesis perspective.