After 21 days of exposure, the somatic growth of the organisms did not indicate an effective concentration where daphnids’ length was reduced in 50 percent for imidacloprid and low food concentrations, and therefore, estimated EC50 values were used to run the MIXTOX toolbox (Jonker et al., 2005). When fitting the data from the imidacloprid – low food levels combination on the IA model, no deviations were obtained, showing that the data fitted the IA model significantly (p