The stability of tebufenpyrad resistance in two-spotted spider mite (Acari: Tetranychidae) under laboratory conditions.

The successful use of chemical rotations to manage insecticide resistance requires reversion between alternate chemical applications. We tested a tebufenpyrad resistant population of Tetranychus urticae Koch after some 55 months laboratory culture without pesticide selection and found LC50 level resistance had dropped from 63.29- to 2.41-fold. However, the population was still heterogeneous with LC99 level resistance at 38.03-fold. It is likely that a lack of reversion contributed directly to the initial tebufenpyrad control failure.