ABSTRACT
The major deficiency in laboratory bioassays that has destroyed their predictive value has been failure to consider effects of pesticides at the level of an arthropod population. The role of variability in rates of population development has been ignored in laboratory bioassays done to predict efficacy. The very precision that ensures the validity of bioassays done to test the significance of selected variables, relationships between chemical structure and activity, and other special purposes negates the predictive value of the experiment with regard to a population. If population samples cannot be collected from the field because of time or practical constraints, a laboratory population could be used to simulate selection of test subjects from a field population. Costs of doing population toxicology may exceed the expense presently incurred in doing a laboratory bioassay, but the reliability of the resultant predictions would be well worth both the extra time and money involved.
