Bioactivity And Synergistic Effect To Imidachloprid Of The Cantharidin And Its Analogues On Aphis Gossypii In Lycium Barbarum

Chemical pesticides have long been a common means and methods in the field of plant protection,which have advantages of convenience and efficiency,and have saved great losses for agricultural production since they were invented and put into use.But the long-term use of a chemical pesticide not only creates environmental pressure,it will also lead to resistance to pests and diseases,resulting in a weakening of pesticide-use of more pesticide-pest control more difficult vicious circle,the agricultural production,ecological environment caused no small loss and pressure,but also lead to pesticide residues and other food safety problems.Biological pesticides,with its low toxicity,low residue,environmental friendliness and other characteristics,have been widely paid attention to Cantharidin,as a kind of natural terpene compound,which is a generalized biological pesticide,it is found to be a kind of good biological activity for many agricultural pests,and as a natural product,it is very friendly to the environment.In addition,the use of a variety of pesticides can be greatly reduced by using the chemical pesticides and reducing the pressure of chemical pesticides on the environment.Chinese wolfberry is an important cash crop,which brings great economic benefit to the western region.Chinese wolfberry aphid,cotton aphid(Aphis gossypii Glover)is one of the major pests,which seriously affects the growth and quality of Lycium barbarum fruit.Bring a lot of economic loss,a large number of chemical pesticides will also produce pesticide residues and other risks,affecting food safety,reduce product yield and quality.In the experiment,Aphis gossypii were used as the experimental object to determine the toxicity of biological pesticides 1%cantharidin EC,5%norcantharidin EC,and chemical pesticides imidacloprid and acetamiprid,17 cantharidin analogues.The results showed that 1%cantharidin EC has the same toxicity as imidacloprid to the aphid in the room.Moreover,the toxicity of 5%norcantharidin EC is a little worse.The 17 cantharidin analogues used did not show the bioactivity to Lycium barbarum aphids.The reason may be that the analogues of these two series are structurally stable.In addition,the experiment included the efficiency of the mixture of the pesticides such as cantharidin,norcantharidin and imidachloprid the field.The results showed that both the cantharidin and norcantharidin were effective toincrease the toxicity of imidacloprid,and the effect of the increase of the cantharidin was greater than that of the norcantharidin.Furthermore,there is the best synergistic effect when proportion of the mixture was 1:2.