What is Insecticide Resistance?
) to permethrin and pyrethrin has been detected in some populations of head lice but the extent of the resistance is not well known. What we do know is that resistance to any pesticide tends to be patchy, high in some areas and low or non-existant in other areas. Patterns of resistance tend to follow patterns of overuse of the pesticide. And, the frequency of resistance can decline when the use of the pesticide is reduced.
