香蕉花蕾注射螺虫乙酯和吡虫啉对黄胸蓟马的防效及药剂在果实中的残留

Efficacy of spirotetramat and imidacloprid against Thrips hawaiiensis on banana plants by flower injection method and their residues in fruit

黄胸蓟马是中国香蕉上重要害虫,生产上对该虫仍缺乏较为有效的防治手段。本研究采用香蕉花蕾注射法施用22.4%螺虫乙酯悬浮剂(SC)和70%吡虫啉水分散粒剂(WG),研究了其对黄胸蓟马的防效,并采用超高效液相色谱-串联质谱法(UPLC-MS/MS)分析了药剂在香蕉果实中的残留。药效试验表明:于香蕉现蕾初期,22.4%螺虫乙酯SC和70%吡虫啉WG分别按有效成分0.12和0.18 g/株的剂量注射施药1次,对黄胸蓟马的防效分别为89%和86%。残留试验表明:花蕾注射施药后,螺虫乙酯和吡虫啉在香蕉果实中的半衰期分别为9.2和6.5 d,且在施药后95 d的香蕉成熟果实中未检测到其残留。本研究表明,香蕉花蕾注射螺虫乙酯与吡虫啉对黄胸蓟马具有良好的防治效果与安全性,可推荐在香蕉园轮换使用。

Thrips hawaiiensis(Morgan)(Thysanoptera: Thripidae) is an important pest on banana in China. However, there is no effective control method for this insect. In this study, the control efficiencies of 22.4% spirotetramat suspension concentrate(SC) and 70% imidacloprid water dispersible granule(WG) aganist T. hawaiiensis by banana flower injection method were studyed. And a method using ultra high performance liquid chromatography coupled with mass spectrometry(UPLC-MS/MS)was employed in the determination of spirotetramat and imidacloprid residues in fruit after banana flower injection. The efficacy trials showed that 22.4% spirotetramat SC and 70% imidacloprid WG were applied once at 0.12 and 0.18 g a.i. per plant in initial budding of banana by flower injection, the control efficacy on T. hawaiiensis were 89% and 86%, respectively. The residue detection results showed that the residue half-lives of spirotetramat and imidacloprid in banana fruit were 9.2 and 6.5 days, respectively.And 95 days after applied, their residues were not detected in the banana mature fruit. This study showed that banana flower injection of spirotetramat and imidacloprid had a good control efficacy on T. hawaiiensis and safety used in banana field, and it could be recommended to alternate use in banana orchards.