The global assessment of the impact of systemic pesticides on biodiversity and ecosystems focuses on neonicotinoids and fipronil, two widely used insecticides. Neonicotinoids, first introduced in the 1990s, have become the most commonly used class of insecticides worldwide, with imidacloprid being the most widely produced. Fipronil, a phenyl-pyrazole insecticide, is also widely used and shares similar toxicological and physicochemical properties with neonicotinoids. Together, they account for approximately one-third of the global insecticide market. These pesticides are systemic, meaning they are absorbed by plants and translocated to all parts, making them effective against herbivorous insects. However, their persistence in the environment and potential for accumulation in various compartments (soil, water, air) raise concerns about their impact on non-target organisms, including insect predators and vertebrates. Neonicotinoids and fipronil act by disrupting neural transmission in invertebrates, with neonicotinoids mimicking neurotransmitters and fipronil inhibiting neuronal receptors. This leads to continuous neuronal stimulation and ultimately to the death of target invertebrates. They can also have lethal and sublethal effects on non-target organisms, and their synergistic effects with other stressors have been documented. Metabolic pathways of these pesticides can produce toxic metabolites, which may contribute to prolonged toxicity. Despite their systemic properties and assumed lower risks to fish and other vertebrates, their widespread use and persistence in the environment suggest significant risks to biodiversity and ecosystems. The global use of neonicotinoids and fipronil has increased significantly since their introduction in the early 1990s, with neonicotinoids being the most widely used insecticides in agriculture. Their use is widespread in various crops, including corn, soybeans, and cotton, and is often applied as seed treatments. However, resistance to these pesticides has been observed in several pest species, including the greenhouse whitefly, whitefly, and Colorado potato beetle. This resistance is a growing concern, as it may limit the effectiveness of these pesticides in the future. The use of neonicotinoids and fipronil extends beyond agriculture, including urban pest control, veterinary applications, and fish farming. Their systemic nature and widespread application have led to their presence in various environmental compartments, raising concerns about their impact on non-target organisms and ecosystems. Despite their benefits in pest control, the potential risks associated with their use, including resistance development and environmental toxicity, necessitate a careful evaluation of their impact on biodiversity and ecosystems. The global assessment of these pesticides highlights the need for a balanced approach to their use, considering both their benefits and potential risks.The global assessment of the impact of systemic pesticides on biodiversity and ecosystems focuses on neonicotinoids and fipronil, two widely used insecticides. Neonicotinoids, first introduced in the 1990s, have become the most commonly used class of insecticides worldwide, with imidacloprid being the most widely produced. Fipronil, a phenyl-pyrazole insecticide, is also widely used and shares similar toxicological and physicochemical properties with neonicotinoids. Together, they account for approximately one-third of the global insecticide market. These pesticides are systemic, meaning they are absorbed by plants and translocated to all parts, making them effective against herbivorous insects. However, their persistence in the environment and potential for accumulation in various compartments (soil, water, air) raise concerns about their impact on non-target organisms, including insect predators and vertebrates. Neonicotinoids and fipronil act by disrupting neural transmission in invertebrates, with neonicotinoids mimicking neurotransmitters and fipronil inhibiting neuronal receptors. This leads to continuous neuronal stimulation and ultimately to the death of target invertebrates. They can also have lethal and sublethal effects on non-target organisms, and their synergistic effects with other stressors have been documented. Metabolic pathways of these pesticides can produce toxic metabolites, which may contribute to prolonged toxicity. Despite their systemic properties and assumed lower risks to fish and other vertebrates, their widespread use and persistence in the environment suggest significant risks to biodiversity and ecosystems. The global use of neonicotinoids and fipronil has increased significantly since their introduction in the early 1990s, with neonicotinoids being the most widely used insecticides in agriculture. Their use is widespread in various crops, including corn, soybeans, and cotton, and is often applied as seed treatments. However, resistance to these pesticides has been observed in several pest species, including the greenhouse whitefly, whitefly, and Colorado potato beetle. This resistance is a growing concern, as it may limit the effectiveness of these pesticides in the future. The use of neonicotinoids and fipronil extends beyond agriculture, including urban pest control, veterinary applications, and fish farming. Their systemic nature and widespread application have led to their presence in various environmental compartments, raising concerns about their impact on non-target organisms and ecosystems. Despite their benefits in pest control, the potential risks associated with their use, including resistance development and environmental toxicity, necessitate a careful evaluation of their impact on biodiversity and ecosystems. The global assessment of these pesticides highlights the need for a balanced approach to their use, considering both their benefits and potential risks.