Qassim University, College of Agriculture and Veterinary Medicine, Department of Plant Production and Protection, Buraydah, Saudi Arabia.
Ain Shams University, Faculty of Agriculture, Department of Plant Protection, Cairo, Egypt.
Braz J Biol. 2022 Jun 10;84:e261262. doi: 10.1590/1519-6984.261262. eCollection 2022.
Promising bioactivities of silver nanoparticles SNP urged researchers of different specialties to evaluate their field-respective activities. Bioactivity towards agricultural pests were the subject of limited publications. In the current study, SNP were synthesized and miticidal activity was evaluated towards old world date mite Oligonychus afrasiaticus (McGregor) (Acari: Tetranychidae) and an associated predatory mite Neoseiulus barkeri Hughes (Phytoseiidae). Under laboratory conditions, SNP displayed significantly higher activity towards O. afrasiaticus (LC50 was 39.7 µg/mL) than N. barkeri (LC50 was 1587.9 µg/mL) which accounts for about 40 folds of selectivity against the pest. SNP exhibited ovicidal activity against laid eggs of O. afrasiaticus (LC50 was 67.8 µg/mL). In field, SNP (at 216 µg/mL) achieved slightly higher efficiency than in laboratory study, 86.5% of population reduction of O. afrasiaticus was achieved and only 18.5% of N. barkeri population was affected. SNP suppressed hatching of 57.1% of laid eggs of O. afrasiaticus. Residues of silver were determined using ICP-OES spectrometry. Initial residues reached 1.83 µg/mL after application then declined with time passing. Estimated daily intake (EDI) reached 1.28 µg/kg/day, calculated for the highest residues obtained and the highest consumption rate of date in the world. Hazard index (Hi) was 0.17 in average. The obtained level of residues appeared to be safe in terms of acute and chronic toxicity references.
银纳米粒子（SNP）具有良好的生物活性，这促使不同专业的研究人员评估其各自领域的活性。针对农业害虫的生物活性是有限出版物的主题。在当前的研究中，合成了 SNP，并评估了其对旧世界枣红蜘蛛（Oligonychus afrasiaticus（McGregor））和相关捕食螨巴氏新小绥螨（Neoseiulus barkeri Hughes）的杀螨活性。在实验室条件下，SNP 对 O. afrasiaticus 的活性明显高于 N. barkeri（LC50 分别为 39.7 µg/mL 和 1587.9 µg/mL），对害虫的选择性约为 40 倍。SNP 对 O. afrasiaticus 已产的卵具有杀卵活性（LC50 为 67.8 µg/mL）。在田间，SNP（在 216 µg/mL 时）的效率略高于实验室研究，可实现 O. afrasiaticus 种群减少 86.5%，仅影响 18.5%的 N. barkeri 种群。SNP 抑制了 O. afrasiaticus 已产卵的 57.1%孵化。使用 ICP-OES 光谱法测定了银的残留量。施药后初始残留量达到 1.83 µg/mL，然后随时间推移而下降。估计每日摄入量（EDI）达到 1.28 µg/kg/天，是基于最高残留量和世界上最高的枣果消耗量计算得出的。平均危害指数（Hi）为 0.17。根据急性和慢性毒性参考值，获得的残留水平似乎是安全的。
