2.4. Determination of Oral LD50 for the Tested Insecticides

Preliminary tests were carried out to determine the median lethal dose (LD₅₀) for commercial formulations of methomyl (MET) and abamectin (ABM) on male rats. For each insecticide, three doses were prepared in water based on active ingredient (a.i.) contents (e.g., 10, 20, and 30 mg/kg b.w. for methomyl; and 10, 20, and 30 mg/kg b.w. for abamectin). Four rats were used for each tested dose, in addition to four rats given water only, serving as a control group. Dosing was performed by gavages with 0.5 mL solutions. The 24h-LD₅₀ values were estimated according to Finney [24]. Based on the obtained LD₅₀ values, the equivalent to the 1/10 was used in the present study (e.g., 2.03 and 1.7 mg/kg b.w., respectively, from MET and ABM).