The plant extracts were previously solubilized in 20 mL of water containing polysorbate 80 (0.015%) at 40◦C, under mechanical agitation during 30 min.
From these solutions, 10 concentrations ranging from 100 to 0.5 ppm were prepared. Plastic containers were filled with 100 mL of these solutions, and 20 larvae were added to each container.