Eco-friendly Water-Based λ-Cyhalothrin Polydopamine Microcapsule Suspension with High Adhesion on Leaf for Reducing Pesticides Loss

Abstract

Recently, innovations of nano/microcarrier formulations have been focused on improving application efficiencies and retention time. In this study, a water-based 2.5% λ-cyhalothrin (LC) microcapsule suspension (CS) was developed by orthogonal test with biodegradable and adhesive polydopamine (PDA) microcapsules (MCs) as carriers. The obtained LC-PDA CS had good suspension properties, flow behavior, storage stability, and rheological properties. LC-PDA CS had higher retention, wettability, and decreased rainwater washing out on the leaves than commercial CS. LC-PDA CS displayed higher insecticidal activity against Lipaphis erysimi compared to commercial CS. LC-PDA CS reduced the toxicity of LC to the aquatic organism Danio rerio compared to LC. The above results demonstrated that LC-PDA CS would be eco-friendly water-based pesticides carrier system for prolonging the retention time on target leaf and reducing toxicity to aquatic organisms.

Effect of λ-Cyhalothrin-Loaded Polydopamine Microcapsule Suspensions on Stress Defenses in the Chinese Mitten Crab, Eriocheir sinensis

“…31 The 96 h LC 50 of the same LC/PDA-MS with respect to Danio rerio was reported as 7.5 × 10 −3 mg/L. 22 In this study, we found that microcapsule LC/PDA-MS is weakly toxic to E. sinensis, with a mean 96 h LC 50 of 6.4 mg/L (with a corresponding 96 h LC 50 value of 161 μg/L with respect to LC in unencapsulated form). Such a high tolerance of crabs to this pesticide can be attributed to the environmentally friendly PDA microcapsule delivery, which lowers the toxicity of LC.…”

“…Then, a 2.5% LC/PDA-MS suspension was prepared by mixing the dispersant and xanthan gum with antifoam in an aqueous solution. 22 2.3. Acute Toxicity Test.…”

“…Blank, dry PDA microcapsules were then dispersed with LC in N , N -dimethylformamide (DMF) and magnetically stirred for 24 h to obtain LC/PDA microcapsules. Then, a 2.5% LC/PDA-MS suspension was prepared by mixing the dispersant and xanthan gum with antifoam in an aqueous solution …”

“…20,21 LC/PDA-MS could be a candidate for use in co-culture systems because of its utilization efficiency and low pesticide decomposition losses. 22 Therefore, it is important to investigate the possible acute and chronic toxicities of LC/ PDA-MS for the co-cultured freshwater organism E. sinensis. In this study, the experiments were conducted according to the guidelines for environmental safety assessments of chemical pesticides, formulated by the Institute for the Control of Agrochemicals (ICAMA) and the Ministry of Environment Protection.…”

“…LC/PDA-MS could be a candidate for use in co-culture systems because of its utilization efficiency and low pesticide decomposition losses . Therefore, it is important to investigate the possible acute and chronic toxicities of LC/PDA-MS for the co-cultured freshwater organism E. sinensis.…”