Study On Insecticidal Toxicity Preparation Of Two New Pesticides And Periplocoside Active In Gredients With Plutella Xylostella

The diamondback moth,Plutella xylostella,is one of the mo st common pests in cruciferous v egetables,It is an migratory,overlapping generations and environ mental strong adaptability pest,wi th the resi stance against c hemical pesticides increasing,the ef fect of che mical control on P.xyloste lla is getti ng lower than before,but t he harm to the environment is increasing.Because of its co mplex components,plant pesticide has led to its complex function,Therefore,pests are not easy to produce resistance to it,It co mes from nature without ecological security,and has a hug e resourc e,Periploca sepium Bunge from Asclepiadaceae is just one of t he most excellent insecticidal plant resources,in particular,it has high act ivity against P.Xylostella.In order to make full use of the excellent plant resources,prolong the s ervice life of low toxicity and high ef ficiency chemical pes ticides,,we used two kinds of new chemicals:Chlorantraniliprole and T olfenpyrad,mixed with ext racts of P.sepium to prepare tw o new pesticides on the basis o f LC50 determination and co-toxico ty coefficient(CTC)m ethods.The results of biaassay showed that When the LC50 ratio of Periplocin and Chlorantraniliprole was 3:7,That is,whe n the actual content ratio of Periplocin and Chlorantraniliprole is 1:33,the ra tio of its to xicity was 146.76,which was more than 120,which had obvious synergism.Similarly,When the LC50 ratio of Pe riplocin and Tolfenpyrad was 4:6,That is,when the actual content rati o of Periplocin and Tolfenpyrad is 1:23,the ratio of its toxicity was 157.46,which was more than 120,which also had obvious synergism.Results of fie ld trials showed that Mixed pesticide A(Periplocin : Chlorantraniliprole = 1:23)750 times,500 times,mixed with B(Periplocin: Chlorantraniliprole= 1:33)1000 times had good control effect on cabbage diamondback moth,A day later,the control effect was between 62.09 ~ 74.28%,3 days later,their control effect was over 80%,After 7 days treatm ent,their control effect w ere more than 90%,there was no significant dif ference between them and the control ef fect of the two chemicals,which showed good control effect on the diamondback moth.