Studies On The Control Effect Of Clothianidin And Dinotefuran Sustained-release Preparations On Greenhouse Whitefly Of Cucumber And Its Residue Detection Method And Digestion Dynamics

In recent years,the amount of pesticides used to control pests such as aphids and planthopper on vegetables,cotton and other crops have been increasing.Due to the neglect of scientific medication and drug resistance,it seriously threatens the control effect.It is an important strategy for sustainable use of pesticide resources to find efficient alternative agents.Neonicotinoids insecticides have been widely used in agricultural production because of their advantages of high efficiency,low toxicity,wide insecticidal spectrum,and low toxicity and high efficiency.Among them,clothianidin and dinotefuran,commonly used in agricultural production,they have been widely used in the pest control of vegetables,fruits and other crops due to their excellent pest control effects.Therefore,their residues in the agricultural ecological environment and their impact on food safety have also attracted the attention of the majority of scholars.Therefore,it is very important to evaluate its safety.There have been many reports on the routine preparation of neonicotinoids pesticide,but few studies on the control effect and performance of neonicotinoids sustained-release pesticide.Therefore,this study selected neonicotinoid pesticide sustained-release preparation to study the degradation law of pesticide residues,sustained-release performance and control effect,aiming to provide theoretical basis for the application of neonicotinoid pesticide sustained-release preparation in agricultural production.In this study,18% clothianidin embedding granules,15%clothianidin chitosan microspheres and 19%dinotefuran gelatin microspheres were selected as the test agents,1%clothianidin granules and 3%dinotefuran granules were selected as the control agents.Characteristics of the tested agents:good sustained release effect,long duration,belongs to the environment friendly pesticide,in line with the concept of sustainable development,the carrier in the tested agents can significantly promote the growth of crops.Will be above reagents respectively applied to the peanut and melon and cucumber,eggplant,cotton,through the establishment of clothianidin and dinotefuran residues detection method,the determination of clothianidin and dinotefuran in crops and soil residual dynamics and final residues,and to investigate the control effects of cucumber in greenhouse whitefly,further explores the correlation between the control effect and the accumulative amount of clothianidin and dinotefuran in leaves.The results of this study are as follows:1.Field experiments were carried out in Rizhao,Shandong Province and Xinxiang,Henan Province.18%clothianidin embedding granules were applied in soil holes during peanut sowing.An ultra-performance liquid liquid-tandem mass spectrometry(UPLC-MS/MS)method was established for the determination of clothianidin residues in peanut and soil.The residues were determined.The results showed that the linear relationship of clothianidin was good in the range of 0.005-2.000 mg/L.The average recoveries of clothianidin were 93%～111%and the relative standard deviations(RSD)were 1.21%～8.13%when the concentration of clothianidin was 0.01～1.00 mg/kg,which met the requirements of pesticide residue detection.The final residues of clothianidin in edible parts of peanut in two experimental sites were 0.007 mg/kg and 0.017 mg/kg in peanut kernels from Rizhao,Shandong and Xinxiang,Henan,respectively.2.A UPLC-MS/MS method was established for the determination of dinotefuran residues in melon,eggplant and cotton leaves.The results showed that dinotefuran had a good linear relationship in the range of 0.005～2.000 mg/L.The average recoveries ranged from 78%～99%with RSDs of 1.41%～7.30%at the concentration of 0.01～1.00 mg/kg.The method is feasible with good repeatability,high precision and accuracy.3.The control effect of 18% clothianidin embedding granules,15%clothianidin chitosan microspheres and 19%dinotefuran gelatin microspheres on whitefly in cucumber was studied,and the accumulative amount of active pesticides in cucumber leaves was detected,and the relationship between the control effect and the accumulative amount was further explored.The results showed that,the control efficacy of the tested insecticides was better than that of the control insecticides,and the correlation between the control efficacy and the accumulative amount was good.When the application dose was 450～750 g a.i./hm2,the residues of clothianidin and dinotefuran in the soil increased with the increase of the application dose,and gradually decreased with the application time.