Balancing efficacy and safety: Particle size-dependent trade-off of suspension concentrate for pest control and non-target ecotoxicity. Hongyi Liu, Wenjie Shangguan, Pengyue Zhao, Chong Cao, Qiliang Huang, Lidong Cao

Source：Advanced Agrochem

Published：August 2026

DOI: 10.1111/pbi.70063

IF：9.2

Abstract：The application of nanotechnology in agriculture has offered promising opportunities for nanopesticides, yet the particle size effects that govern their performance remain poorly understood, especially regarding the trade-off between enhanced bioactivity and potential non-target organisms risks. In this study, different particle sizes of 15% indoxacarb suspension concentrate (IDC SC), 10% chlorfenapyr SC (CFP SC), and 20% cyproflanilide SC (CFL SC) were prepared, ranging from micrometer to nanometer scales. As particle size decreased, both storage and colloidal stability improved, along with enhanced wetting and spreading performance to some extent. The biological activity of SC against Plutella xylostella decreased as the particle size increased. The LC50values of IDC-S, IDC-M, and IDC-L for P. xylostella at 48 h were determined by the leaf-dipping method as 2.15, 4.66, and 11.25 mg/L, respectively. The bioactivity of CFP SC followed the same particle size-dependent trend as IDC. In addition, indoor toxicity tests indicated that the LC50of Micro-CFL against P. xylostella at 48 h was 0.165 mg/L, which was approximately 5.3 times that of Nano-CFL. Furthermore, the acute toxicity of IDC SC to zebrafish reduced as particle size increased, with LC50values ranging from 9.49 to 23.53 mg/L, while CFP and CFL SC showed no significant particle size-dependent effect. These different trends suggest that the particle size effect is not universal but rather depends on the physicochemical properties and modes of action of individual active ingredients. The present results highlight that the particle size of nanopesticides is a double-edged sword, and achieving an optimal balance between biological efficacy and environmental safety must be a central consideration in the future design and application of nanopesticides. This study provides case-based foundations for understanding this underexplored trade-off and offers practical guidance for size-directed formulation optimization.