新烟碱类杀虫剂种子包衣防治麦蚜的可行性评价

为评价不同新烟碱类杀虫剂处理种子防治小麦蚜虫的应用潜力,采用种子包衣法分别在室内及田间比较了吡虫啉、噻虫嗪、啶虫脒、烯啶虫胺、噻虫啉防治小麦蚜虫的效果及安全性,并测定了吡虫啉和噻虫嗪的持效、对天敌和小麦产量的影响及其在小麦籽粒中的最终残留量。结果表明,在2.4、3.6和4.8 g/kg种子剂量下,啶虫脒明显降低小麦出苗率,而其它药剂均无显著影响;至抽穗前烯啶虫胺、啶虫脒和噻虫啉对麦蚜的防效低,吡虫啉和噻虫嗪则均有较高防效,在58.17%以上,而在小麦抽穗扬花期防效下降,为33.57%~60.46%。吡虫啉和噻虫嗪对叶部麦蚜防效均相应高于穗部。与喷雾处理相比,吡虫啉、噻虫嗪各剂量种子包衣对瓢虫和蚜茧蜂等天敌昆虫影响小,在3.6、4.8 g/kg种子剂量下,小麦千粒重和产量无显著差异,且在小麦籽粒中的残留量低。表明吡虫啉和噻虫嗪种子包衣防治麦蚜的应用潜力大。

Feasibility for controlling wheat aphids by seed dressing with neonicotinoid insecticides

To evaluate the potential of neonicotinoid insecticides in controlling wheat aphids, the laboratory and field trials were conducted by seed dressing with imidacloprid, thiamethoxam, acetamiprid, nitenpyram and thiacloprid for comparing their efficacy and safety to wheat. The persistence effect, their effects on natural enemy insects and yield of wheat, and the residues in wheat grain treated by imidacloprid and thiamethoxam were also investigated. The results showed that all treatments had no impact on the emergence rate of wheat seeds except acetamiprid at 2.4, 3.6 and 4.8 g/kg seeds. The treatments with nitenpyram, acetamiprid and thiacloprid had low control efficacy to wheat aphids, while the control efficacy of the treatments with imidacloprid and thiamethoxam were high. Imidacloprid and thiamethoxam treatments at 2.4, 3.6 and 4.8 g/kg seeds could effectively control wheat aphids at the early and middle growing stage of wheat plants, and all the effects were higher than 58.17%. At the booting stage, the control efficacy was 33.57%-60.46%, which was lower than that at former stages. The control efficacies on leaves were higher than that on ears at the same time when treated with imidacloprid and thiamethoxam. Compared with the spray treatment, seed treatments with imidacloprid and thiamethoxam at all rates had less effect on natural enemies, such as ladybirds and aphid parasites. There were no significant differences in the thousand-grain weight and yield between imidacloprid and thiamethoxam treatments and spray treatment with imidacloprid at 3.6 g/kg and 4.8 g/kg seeds. The residues of imidacloprid and thiamethoxam in wheat grains were lower than that under spray treatment. These results indicated that imidacloprid and thiamethoxam have great application potential for controlling wheat aphids by seed dressing.