六种药剂对桃粉蚜毒力及刺吸取食行为测定分析

The toxicity of six insecticides to Myzus persicae and their impacts on stinging behavior

【目的】筛选对桃粉蚜Myzus persicae毒力较好的药剂及复配增效配比,为其化学防治提供理论依据。【方法】以室内饲养的桃粉蚜成虫为材料,采用药液浸渍法测定6种药剂对桃粉蚜成虫的室内毒力。试验设置6个浓度梯度。根据毒力测定结果将氟啶虫酰胺、氟啶虫胺腈2种药剂按照1∶1、1∶5、5∶1、1∶10和10∶1的比例进行复配,对照为清水,记录0、2、4、6、12、24、36、48和72 h后桃粉蚜的死亡数,计算药剂的LC50及共毒系数(Co-toxicity coefficient,CTC)。在各单剂的6个浓度梯度处理中,分别取5头成虫置于刺吸电位仪(Electrical penetration graph,EPG)下进行取食行为观察。【结果】6种药剂对桃粉蚜成虫的毒力、药效大小依次为:氟啶虫胺腈>氟啶虫酰胺>吡虫啉>高效氯氟氰菊酯>双丙环虫酯>噻虫嗪。氟啶虫酰胺和氟啶虫胺腈复配联合毒力结果表明,混配药效均高于单剂,且表现出不同程度的增效作用,其中氟啶虫胺腈∶氟啶虫酰胺比例为10∶1增效较大,CTC为3832.015。EPG结果显示,氟啶虫胺腈E波总刺探持续时间最短(36.16 min),刺探次数最少(20.50次),噻虫嗪总刺探持续时间最长(173.82 min),总刺探次数最多(48.00次)。氟啶虫酰胺和氟啶虫胺腈复配比例为10∶1的E波总刺探持续时间最短(41.31 min),刺探次数最少(15.50次),1∶10的总刺探持续时间最长(105.59 min),刺探次数最多(29次)。综合EPG测定数据,其结果与毒力测定结果相符合。【结论】单剂氟啶虫胺腈的防治效果和氟啶虫酰胺与氟啶虫胺腈复配比例10∶1增效最大,可在桃粉蚜发生严重时喷施,为桃粉蚜有效防治提供技术支撑。

[Aim]To investigate the toxic efficiency of 6 insecticides against Myzus persicae,providing a theoretical basis for its chemical control.[Methods]Adult M.persicae were reared indoors and the toxicity of 6 insecticides to adult M.persicae was determined using the liquid impregnation method.6 concentration gradients were established.Based on the toxicity test results,fluosamide and fluonitrile were combined in ratios of 1∶1,1∶5,5∶1,1∶10,10∶1.Water was for the control treatment.The LC50 and co-toxicity coefficient(CTC)were calculated based on the mortality rate of M.persicae at 0,2,4,6,12,24,36,48,and 72 h.The electrical penetration graph(EPG)technique was used to monitor the feeding behavior of 5 adult M.persicae across the 6 concentration gradient treatments for each of the insecticides.[Results]The findings indicated that the toxicity and efficacy hierarchy of the 6 insecticides against adult M.persicae was fluonitrile>fluosamide>pyrazine>high efficiency cypermethrin>dipropyl ester>thiothiazide.The results of the combined toxicity test showed that the efficacy of the combined insecticide mixture was higher compared to the individual insecticides.Additionally,there was variation in the synergistic effect.The ratio of fluonitrile to fluosamide was 1∶1,with a CTC value of 3832.015.The EPG results showed that the duration of the fluonitrile E wave was the shortest(36.16 min)and the least frequent(20.50 times).In contrast,the duration of thiothiazide was the longest(173.82 min)and the most the frequent(48.00 times).When the ratio of fluosamide to fluonitrile was 10∶1,the E wave exhibited the shortest total duration(41.31 min),the least frequent probes(15.50 times),the longest probe duration(105.59 min),and the highest number of probes(29 times).Based on the EPG data,the results were consistent with the toxicity test.[Conclusion]The findings of this study demonstrated the control efficacy of a single dose of fluonitrile combined with fluosamide at a ratio of 10∶1.This mixture could be applied during severe aphid infestations,providing technical support for the effective control of M.persicae.