ABSTRACT
Precise estimation of response in a bioassay can be ensured by use of adequate sample sizes, careful attention to dose placement, and careful attention to sound experimental design. Although use of any method that better simulates exposure makes an assay somewhat more realistic, the overall predictive value of the experiment does not necessarily increase. The scoring process most often used in pesticide bioassays is binary: dead vs. alive. Laboratory bioassays provide an ideal means to test whether one or more specific variables significantly affect response to a pesticide. The underlying problem in the multiple bioassay approach is that the relative contributions of the various aspects of pesticide effectiveness to overall efficacy are unknown. One definition of optimal time of application is the time during population development when a pesticide will achieve maximum effect with minimum active ingredient. Early attempts to identify optimal time consisted of simple empirical estimates.
