摘要:
2009～2010年,采用稻秆浸渍接虫法,测定了福建省3个地区的褐飞虱田间种群对6种杀虫剂的敏感性并进行抗性分析,在仙游县晚稻田褐飞虱初孵若虫始盛期,采用喷雾法对6种药剂的田间控制作用进行了研究,结果表明:同一个种群的褐飞虱若虫对同一种药剂的敏感性随着虫龄的增加而降低;烯啶虫胺对不同地理种群的褐飞虱若虫均表现出最高的毒力,对3地种群的褐飞虱2龄、3龄、4～5龄若虫的LC50分别为0.941 7～1.0167 mg·L-1、1.1872～1.341 0 mg·L-1、1.610 2～1.9370 mg·L-1,异丙威的毒力最低,对3地种群的褐飞虱2龄、3龄、4～5龄若虫的LC50分别为37.118 3～46.733 5 mg·L-1、45.924 1～56.9504 mg·L-1、50.9938～70.1912 mg·L-1;抗性分析表明,福州市褐飞虱种群对吡虫啉达高抗水平,龙海市和仙游县种群达极高抗水平,3个不同地点的褐飞虱种群对噻虫嗪、噻嗪酮、异丙威均为中等抗性水平,对烯啶虫胺均处于敏感阶段;田间控制作用试验结果表明,6种供试药剂中,以烯啶虫胺和异丙威的速效性最好,持效性则以烯啶虫胺和吡蚜酮的最好;在田间褐飞虱初孵若虫发生始盛期,用吡虫啉(a..i)30～45 g·hm-2剂量喷雾,施药后3～7 d内可以有效控制褐飞虱的为害,但在吡虫啉对褐飞虱的防治效果明显下降及较高抗性等问题的情况下,不宜再继续长期大量地使用吡虫啉防治褐飞虱,应制定进行合理轮换用药的抗性治理策略,防止褐飞虱抗性快速发展及种群大暴发,烯啶虫胺和吡蚜酮是作为替代吡虫啉或轮换使用的理想药剂。
关键词:
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褐飞虱 /
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田间种群 /
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杀虫剂 /
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毒力 /
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抗性
Abstract:
The stem-dipping of rice stalks was used to determine the susceptibility of Nilaparvata lugens(Stl)to 6 insecticides.Different field populations collected from 3 regions in Fujian from 2009 to 2010 were used for the study.The experiment was conducted by spraying the insecticides during the beginning of the peak N.lugens nymph-hatching in the late-rice growing field at Xianyou County.The results showed that the susceptibility of N.lugens nymphs to insecticides decreased with the insect's age.The toxicity of nitenpyram to N.lugens was the highest among the 6 insecticides.The LC50 on the 2nd,3rd and 4-5th instar nyphms of N.lugens populations were 0.9417-1.0167 mg·L-1,1.187 2-1.341 0 mg·L-1 and 1.6102-1.9370 mg·L-1,respectively.Isoprocarb exhibited the lowest toxicity among all insecticides tested,with LC50 on 2nd,3rd and 4-5th instar nyphms of 37.118 3-46.7335 mg·L-1,45.924 1-56.9504 mg·L-1 and 50.993 8-70.1912 mg·L-1,respectively.The insecticide resistance to imidacloprid of the N.lugens population in Fuzhou was considered high,and the population in Longhai and Xianyou extremely high;and,that of all 3 N.lugens populations moderate to thiamethoxam,buprofezin and isoprocarb.All 3 populations were susceptible to nitenpyram.Among the 6 insecticides,nitenpyram and isoprocarb exhibited a control effect on the field populations of N.lugens more rapidly than the others.But,the control effect of nitenpyram and pymetrozine lasted longer than that of the others.In the beginning of the peak N.lugens nymph-hatching,imidacloprid was effective with a dosage of 30-45 g(a.i.)hm-2.In recent years,the serious insecticide resistance and the declined efficacy of imidacloprid,long-term applications to control N.lugens with large dose have become inappropriate and inpractical.Alternative strategies,such as alternating and rotating the use of different insecticides,need to be explored.It was postulated that nitenpyram and/or pymetrozine could be the candidates as replacements for imidacloprid.
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