Temperature-dependent, time-dose-effect model for pesticide effects on growing, herbivorous arthropods: Bioassays with dimethoate and cypermethrin.

A toxicokinetics-based, temperature-dependent survival model for growing animals with oral uptake of toxicants is used to analyze the results of two pesticide bioassays. With this approach, we aim at simultaneously addressing two complementary goals of pesticide bioassays, namely to assess species sensitivity and to elucidate underlying mechanisms of toxic effects. As test organisms, newly hatched larvae of the chrysomelid beetle Gastrophysa polygoni L.

Comparison of the toxicity of dimethoate and cypermethrin in the laboratory and the field when applying the same bioassay.

The present paper studies the relationship between laboratory- and field-based survival data of beetle larvae sprayed with either dimethoate or cypermethrin. The comparison for dimethoate was based on an earlier constructed pesticide-effect model derived from greenhouse data. To predict field effects, the model was supplied with field data for temperatures, the insecticide concentrations on the plants, and the control mortality rate of the beetles.