Comparative toxicity of two azadirachtin-based neem pesticides to daphnia pulex

摘要

Azadirachtin(AZA)-based pesticides(Neemix~TM and Bioneem~TM) demonstrated toxicity in 48-h nonrenewal toxicity assays using Daphnia pulex at levels that were comparable with several organophosphate pesticides. The median lethal concentration (LC50) values for the two neem pesticides were found to be 0.028 and 0.033μl/ml, respectively. The LC50 value for nonformulated (95/100 pre)AZA was determined to be 0.382 μg AZA/ml. Neemix and Bioneem were exposed to air and northern sky daylight in a light box at 24 and 37°C for 1, 3, 6, and 9 d. Standard 48-h acute toxicity tests were used to determine the effect of aging in these dry environmental conditions.