吡虫啉与杀虫单对水稻飞虱和螟虫联合作用研究

在室内测定了吡虫啉与杀虫单混配对水稻褐飞虱Ｎｉｌａｐａｒｖａｔａｌｕｇｅｎｓ和二化螟Ｃｈｉｌｏｓｕｐｐｒｅｓｓａｌｉｓ的联合作用,并进行了田间试验。结果表明吡虫啉与杀虫单复配对褐飞虱、二化螟有相加和增效作用,以配比1∶20～1∶40增效作用最好。吡虫啉对二化螟有较高的毒杀作用,以点滴法和稻茎浸渍法测得其致死中量为0 8873μｇ/头和0 3743ｍｇ Ｌ,分别是杀虫单的5 168倍和2 19倍。田间试验表明,在室内试验中ＣＴＣ值较高的配比(1∶22～1∶39)的药剂在田间对水稻飞虱和螟虫均有较好的防治效果,防治稻飞虱的防效在94 7%以上,防治二化螟的效果在55 6%～90 6%之间,防治三化螟的效果在55 13%～95 41%之间,防治稻纵卷叶螟的效果在81 6%以上。

Co-efficient of mixed imidacloprid and monosultap to Nilaparvata lugens and Chilo suppressalis

The bioactivity and co-toxicity coefficent of mixed imidacloprid and monosultap to Nilaparvata lugens(Stl)and Chilo suppressalis(Walker)were determined in the lab,and their efficacy was tested in the field.The results showed that the co-toxicity coefficent of mixed imidacloprid and monosultap to N.lugens and C.suppressalis were additive and synerpism with the proportion is 1∶20～1∶40.The results showed that based on LC_~50 and LD_~50 ,the bioactivity of imidacloprid to C.suppressalis was 2.19～5.168 times than that of monosultap.The LC_~50 of imidacloprid to C.suppressalis was 0.3743 mg/L by ear residue bioassay method,and the LD_~50 is 0.8863 μg/borer by topical application.Results of field trials from Hubei,Sichuan and Guangdong Provinces,showed that the efficacy to mixed imidacloprid monosultap was good,being consistant with the results in lab.The control effect was more than 97% to planthopper, 55.6%～90.6% to striped rice borer, 55.13%～95.41% to paddy stem borer,and more than 81.6% to rice leaf roller.