A theoretical examination of the classical theory of inheritance of insecticide resistance and the genetics of time to knockdown and dry body weight inSitophilus oryzae(L.) (Coleoptera: Curculionidae)

Abstract

AbstractWith the decline in production of new insecticides, the development of resistance is likely to become more of a problem than at present. Models of the spread of resistance genes may become integral parts of many management programmes. A critical examination is made of the classical theory of inheritance of resistance, i.e. the spread of a single resistance- conferring allele through a population. The theoretical considerations suggest that simple Mendelian inheritance is unable always to account for the development of resistance. It is suggested that some resistance factors may be under multigenic control and that such inheritance could account for the rate at which resistance sometimes develops. Following on from the theory, an analysis was made of time to knockdown and dry body weight inSitophilus oryzae(L.). A half-sib experimental design was employed which enabled quantitative analyses of the characters to be made. Both characters had substantial heritabilities and were phenotypically correlated. The analysis also indicated a positive genetic correlation between the characters. The implications for the development of tolerance in the light of the genetic analysis are discussed.