Genetics of resistance of houseflies (Musca domestica L.) to pyrethroids. I. Knock‐down resistance

Abstract Knock‐down resistance in Musca domestica, which provides cross‐resistance between DDT and pyrethroids, has been genetically separated from three different resistant populations. After careful purification of each factor, the cross‐over rates between them and the visible mutants brown body and green eye were estimated. This indicated that these factors are probably identical. The influence and implications of the knock‐down resistance factor, kdr, on the total resistance of populations that include it are briefly discussed.