Influence of pyrethroid and neonicotinoid insecticides on post-metamorphic amphibians (literature review)

Abstract

Agricultural activity in the global world is accompanied by the use of a significant number of synthetic insecticides for the control of insect pests. Pyrethroid and neonicotinoid insecticides are among the widely used insecticides in many countries for the control of crop pests. They are a generation of synthetic insecticides that have replaced the more environmentally stable organophosphorus and organochlorine compounds. Pyrethroid and neonicotinoid insecticides were thought to have low toxicity to vertebrates, leading to their widespread use and increased production. However, many studies have emerged in recent decades that have shown that, under certain conditions, these substances can cause significant damage to the internal systems of amphibians. Recently, special studies have also revealed the toxic effects of pyrethroids and neonicotinoids on the post-metamorphic stages of amphibians, which had previously been ignored. It has also been noted that abnormalities in gastrointestinal tract functions occur, leading to abnormalities in the digestive system. Pyrethroid and neonicotinoid insecticides have been shown to affect the biochemical and histological parameters of amphibians. The possible genotoxicity of these insecticides resulted in producing erythrocytes with abnormal nuclei and an increased number of micronuclei in amphibian cells. Meanwhile, changes in the activity of antioxidant enzymes and increases in lipid peroxidation products could be used as biomarkers of oxidative stress in amphibians under the influence of pyrethroid and neonicotinoid insecticides. The available literature also indicates that these insecticides appear to affect the nervous system of amphibians and induce changes in their behaviour. At the same time, our data suggest that it is neuromolecular biomarkers that can be practised to determine the toxic effects of insecticides on non-target species. Such biomarkers can be used in the context of the low-dose influence of insecticides, which however requires additional research on amphibians.