The Costs of DDT Resistance in Drosophila and Implications for Resistance Management Strategies

摘要

32.1 Introduction To prevent further rapid development of resistance to new and currently effective insecticides in important crop pests, it is necessary to develop effective control strategies. Models of the evolution of resistance to xenobiotics and pathogens often share the central assumption that resistance carries a fitness cost. This assumption is based on studies of evolutionary biology, population genetics, and physiology. Evolutionary biology dictates that any resistance must involve a large modification of the previous phenotype and that a large phenotypic modification is therefore deleterious within the ancestral environment. Population genetics predicts that although resistance confers an advantage in the presence of the selective force, resistance genes are assumed not to approach fixation in natural populations and the observed frequency is assumed to be the net result of the selective advantage in the presence of selection and its cost in the absence of selection. Finally, our knowledge of the molecular basis of resistance-associated mutations has reinforced the concept that mutations carry a cost as we can derive hypotheses based on the altered function of the associated enzymes or receptors.