2.4. Determination of Median Lethal Concentration (LC50) of Systemic Insecticides in Curry Leaf in Protected Cultivation

The curry leaf trees were treated with thiamethoxam + chlorantraniliprole and thiamethoxam, as these insecticides performed best in bioassay 1 (Section 2.3). Different concentrations that provided mortalities between 5 and 95% of the individuals were diluted in 50 mL of distilled water and applied via drench to each curry leaf. After seven days, ten insects were confined on each plant in cages made of voile. The mortality of D. citri was evaluated at 1, 2, 3, 5, and 7 days after confinement, in order to determine the best time to evaluate the effects of the insecticides. The design was completely randomized, in which each treatment (concentration) consisted of four replicates of 10 adult insects each. The concentrations used were determined using Finney’s equation [32], where the minimum and maximum concentrations were determined in preliminary tests.