Study On Culling A Chemical To Replace Mirex To Control Coptotermes Suzhouensis

This paper studied the knocking down,antifeeding,repellent and toxicant transmitting effects of fipronil,hexaflumuron,sulfluramid and imidacloprid to Coptotermes suzhouensis Xia et He.To explore the mixture of these pesticides to against Coptotermes suzhouensis Xia et He by toxicant transmitting,and judge the effects of these pesticides to control Coptotermes suzhouensis Xia et He by the records in lab.The feasibility of using these pesticides to control termites was based on the results.Fipronil and imidacloprid were shown to have strong knocking down and antifeeding effects,but no repellent effect.Contact poisoning of termite with membrane,yielded the KT₅₀of 31.99h,57.69h respectively when concentrations of fipronil and imidacloprid were 25mg.L^-1.Sulfluramid had weak killing and antifeeding,no repellent action,and the KT₅₀was 86.02h with the concentration of 500 mg.L^-1,the rates of antifeeding was 38.37%with the concentration of 1000mg.L^-1 and the time was 24 hours.Hexaflumuron had no strong knocking down and antifeeding effects.The rates of antifeeding was 36.43%with the concentration of 5000mg.L^-1,when the time was 24 hours.Fipronil had strong toxicant transmitting to Coptotermes suzhouensis Xia et.The cumulat death rates of termites was 73.33%when the second time of toxicant transmitting on the 21^std.Sulfuramid had some stomach-toxicant transmitting effects, the death rates of termite was 58.89%when the second time of toxicant transmitting on the 21^std.The mixture of imidacloprid and hexaflumuron had high stomach-toxicant transmitting,and the mixture had 2 times transmitting effects in some concentrations when the dosage of imidacloprid/hexaflumuron= 1/200,1 / 100,1/50,1 / 10.The duplicate matches of sulfluramid and hexaflumuron had some stomach -toxicant transmitting effects.The mixture had 2 times transmitting effects wih the concentration of 50mg.L^-1,100mg.L^-1and 200mg.L^-1when sulfulramid/ hexaflumuron=100:1,it also had 2 times transmitting effects when sulfulramid/ hexaflumuron=50:1 with the concentration of 200mg.L^-1.The mixture of fipronil and hexaflumuron had strong killing and antifeeding effects,and no repellent effect.Contact poisoning of Coptotermes suzhouensis Xia et He with membrane,yielded the KT₅₀of 33.16h with the concentration of 25mg.L^-1. The rates of antifeeding was respectively 10.13%,24.61%and 95.32%when the concentration was 25mg.L^-1,50mg.L^-1and 500mg.L^-1.The mixture of fipronil and hexaflumuron were shown to have very strong stomach-toxicant transmitting.When fipron/hexaflumuron=l:50,the mixture had 3 times transmitting effects with the concentrations of 50mg.L^-1and 100mg.L^-1,and 0.25%fipronil.hexaflumuron medicinal power had 2 times contact-toxicant transmitting effects.0.5%baits of Mirex had 3 times stomach-toxicant transmitting effects to Coptotermes suzhouensis Xia et He,and 10%medicinal power of Mirex also had 3 times contact-toxicant transmitting effects to termites.Though Mirex had the better toxicant transmitting effects than the mixture of 0.25%fipronil·hexaflumuron,was the best pesticides to control Coptotermes suzhouensis Xia et He,0.25%fipronil·hexaflumuron was a potential pesticede,and was prospect.It will need to be verified in field whether 0.25%fipronil·hexaflumuron can control termites.