Mean percentage error (%) of individual tolerance (IT) and stochastic death (SD) model when pulsed (PT), constant (CT), or all data was used for calibration of the survival model for Gammarus pulex exposed to imidacloprid.

1Pulsed treatment with a short interval in uncontaminated water between imidacloprid pulses.2Pulsed treatment with a long interval in uncontaminated water between imidacloprid pulses.