INSECT RESISTANCE TO INSECTICIDES AND DYNAMICS OF INSECT TOXICOLOGY

Abstract  In field control of insects with insecticides, insects could develop different degrees of resistance. When resistance data were reviewed more extensively, it was found that detoxication alone cannot explain very high resistance of house flies to OC1 (organochlorine) insecticides. As a group, flies can develop much higher resistance to OC1 than to OP (organophosphorus) insecticides. although OPs are generally less stable in insects. With the consideration of the dynamics of insect toxicology. one can readily realize the importance of penetration. Based on the rates of penetration and detoxication. slow penetration is a limiting factor for detoxication. To further explain the observed results on the control of S (susceptible) 'and R (resistant) insects, several correlation curves were plotted. on the relationship between physical and biological factors. These relationships not only indicate approximate degrees of resistance of flies to OPs and OCls, but also help select new toxicants. For example, fast speed of action index of insecticides can produce lower resistance, and the analysis of the joint action of insecticides helps evaluate the types (same or different) of mode of action for controlling resistant insects.