Comparing the individual EC50 values of each chemical, having as endpoint reproduction, obtained from the mixture under culture conditions, this study (for imidacloprid EC50=5.65 mg/L and for nickel EC50=282 µg/L) shows a reproducibility of the results of EC50 values of the single exposures obtained from the previous study ofPavlaki et al. (2011) (for imidacloprid EC50=5.5 mg/L and for nickel EC50=289 µg/L).