Bioefficacy and stablization of hydrolytically unstable pesticide in water based microemulsion against Periplaneta americana

Chlorpyrifos microemulsion was formulated using karanja (Pongamia glabra) and jatropha (Jatropha curcas) non polar filtrate as a dispersed phase. Process of stable microemulsion development was optimized for parameters such as non-ionic surfactants concentration and chlorpyrifos concentration with high physical and chemical stability. Chlorpyrifos hydrolytical unstability was analyzed by GC-FPD Physical stability of microemulsion was optimized in terms of shelf life of the chlorpyrifos microemulsion. Particle size analysis and viscosity data also confirm the swollen miceller solubilization characteristics of the microemulsion system. The chlorpyrifos microemulsion (ME) and emulsifiable concentrate (EC) containing karanja and jatropha non-aqueous filtrate with concentration of 20–100 ppm gave 55–100% mortality rates against Periplaneta Americana (Order: Blattodea, Family: Blattidae) within 24 hours. The LD₅₀ values recorded for the microemulsion and emulsifiable concentrate were 1.277 and 1.347 mgl-1 with karanja and jatropha non-polar filtrate.