Cross-resistance assessment in cartap- and esfenvalerateselected strains of the diamondback moth, Plutella xylostella (L.) (Lepidoptera:Plutellidae)

Effective control of the diamondback moth (DBM), Plutella xylostella (L.) (Lepidoptera: Plutellidae) has become critical due to the genetic ability of the insect pest to develop resistance to insecticides. Alternating or rotating the use of insecticides that do not show cross-resistance is an important component of an effective resistance management strategy, as it helps prevent resistance development or regain susceptibility in an already resistant arthropod pest population. In this study, cross-resistance to selected insecticides in cartap- and esfenvalerate-selected strains of DBM was assessed in the laboratory, using the leaf-dipping method. The esfenvalerate-selected strain exhibited moderate cross-resistance to abamectin and a very low cross-resistance to cartap. The cartap-selected strain also displayed a very low cross-resistance to esfenvalerate but showed no cross-resistance to abamectin. Alternating cartap and abamectin would therefore help to effectively manage insecticide-resistance development in the DBM.