Research On The Formula And Preparation Of Water Dispersible Granule Against Solenopsis Invicta Control With Firronil Mound Drenches

Pesticide water dispersible granule is one of the development directions of pesticide formulations.It has the advantages of high pesticide content,low dust,solvent-free,environment-friendly and easy to use,and is popular in domestic and foreign markets.Water dispersible granules can be quickly disintegrated into water and dispersed,forming a highly suspended water dispersion system,and are very effective against target organisms.Based on the literature review and market investigation,this study aims to develop environment-friendly fipronil and bifenthrin water dispersible granules.The study provides a detailed data and scientific basis for the development and prevention of fipronil and bifenthrin dispersible granules,and provides a solution for the reduction of pesticide use,with a broader application prospects of better economic benefits.In this study,research on the formula of fipronil 50% WG and bifenthrin 30% WG,quality testing analysis method and bioassay toxicity against the red imported fire ant,Solenopsis invicta Buren,was conducted.In addition,the composition and the proportion of each component of fipronil 50% WG and bifenthrin 30% WG was determined and the biological activity of this formulation was determined by toxicity measurement at the same time.The main results were concluded as follows:After screening in auxiliaries(wetting agents,dispersing agents,binders,antifoaming agents and disintegrating agents)and carriers,the best formula of fipronil 50% WG was confirmed ultimately: fipronil(50%),sodium dodecyl benzene sulfonate(5%),D-425(8%),potassium carbonate(6%),Agnique Soap L(0.2%)and kaoline(30.8%).The best formula of bifenthrin 30% WG is as follows: bifenthrin(30%),wetting agents-20(5%),Morwet EFW(7%),ammonium sulfate(4%),NPS-XPJ(0.2%)and white carbon black(53.8%).Through the study of quality testing and analysis of the formulations,we determined that the active ingredient content of fipronil 50% WG and bifenthrin 30% WG was 51.05% and 30.82%,respectively,and the suspensibility rate were 98% and 93%,respectively.Results of hot storage test showed that decomposition rate of the active ingredient of fipronil 50% WG and bifenthrin 30% WG were 1.28% and 1.42%,respectively,which illustrate that both formulations have good hot storage stability.Wetting time,suspension rate,dispersity,disintegration time and other indicators are in line with the standard.The contact toxicity of self-made fipronil WG and bifenthrin WG against worker ants of the red imported fire ant were evaluated by pesticide-membrane method after treating 24 h.The results showed that all the worker ants of the red imported fire ant have higher sensitivity to fipronil WG,and the LC50 all below 0.5 ?g/mL after treating 24 h by fipronil WG,and the contact toxicity of queen ants is lower than the worker ants,24 h LC50 value higher than 15 g/mL.Although the contact toxicity of bifenthrin is lower than fipronil,the effect against worker ants of the red imported fire ant is better than it,and the contact toxicity of bifenthrin against queen ants of the red imported fire ant is weakest.