Toxicity risks to honeybees and non-target arthropods from major pesticides in tea plantations

Tea plantations represent a relatively stable ecosystem, yet improper pesticide use poses significant risks to human and environmental health. This study aimed to assess the risks of major insecticides registered for use in tea plantations to honeybees and non-target arthropods (NTAs). A list of registered active ingredients was compiled, and 11 representative insecticides were selected for primary risk assessment. Data on insecticide use strategies including dosage, number of applications, and application method, along with ecotoxicological characteristics, were collected to calculate predicted exposure concentrations (PEC), predicted no-effect concentrations (PNEC), and acute risk quotients (RQ = PEC/PNEC). For honeybees, only chlorantraniliprole and afidopyropen posed an acceptable risk (RQ ≤ 1). In contrast, the RQ values for bifenthrin, imidacloprid, clothianidin, malathion and abamectin were 101–585 times higher than acceptable levels. For NTAs, only diafenthiuron, chlorantraniliprole, tolfenpyrad, and afidopyropen posed acceptable risks; while the majority of other insecticides including lambda-cyhalothrin, bifenthrin, imidacloprid, clothianidin, and malathion, exhibited moderate to high risks. These findings indicate that the use of high-risk pesticides in tea plantations should be restricted or phased out. In the interim, adopting mitigation strategies like chemical substitution with low-risk alternatives, optimized application timing, and integrated pest management (IPM) is crucial to protect honeybees, NTAs, and the broader ecosystem.