Abstract: This paper reviews the current progress of the relationship between Kdr- type resistance and sodium channel. Toxicological and electrophysiological studies have demonstrated the presence of Kdr-type resistance in many pyrethroid-resistant insects. Molecular genetic evidence has been presented that Kdr-type resistance is linked to a sodium channel locus in many pyrethroid-resistant insects. Moreover, a number of recent studies have already demonstrated that several mutations in structure gene of sodium channel are associated with Kdr-type resistance, which is thought to be the mechanism of reduced sensitivity of the insect nervous system to pyrethroid insecticides. However, several problems, such as the conservation and distribution of point mutation, remain to be clarified.

Key words: insect nerve system, pyrethroids, Kdr type resistance, sodium channel