Susceptibility of the taiga tick Ixodes persulcatus Schulze to pyrethroids.

The susceptibility of the taiga tick Ixodes persulcatus Schulze to 15 pyrethroids has been evaluated. The knockdown time after exposure of ticks to pyrethroids tested was quite similar. It was revealed that the lethal doses of type I pyrethroids (permethrin-like) induced the rapid attachment of ticks to host. In contrast, the fatal poisoning with type II pyrethroids (alpha-CN-pyrethroids) made the ticks unable to attach completely. Possible mechanisms of the acceleration and the prevention of attachment are discussed.