Abstract: For appraising the effect of mosaic control on evolution of insecticide resistance, we simu late the effect in the laboratory by using a syn thetic population of Culex pipiens pallens as model insect. A synthetic strain (M) was constituted at the R individual frequency of 0.1 for both malathion and fenvalerate (named RM for monofactorical and RF for polyfactorical, re spectively) And then the M strain was divided into three sub-strains at F_l. The Rmf sub strain was treated by mosaic control with malathion and fenvalerate, and compared with Rm and Rf sub-strain which were treated separately with one of the above insecticides. After 10 generations, the resistance of Rm and Rmf to malathion was 266.4- and 6.1-fold, respectively, but the resistance of Rf and Rmf to fenalerate was both more than 243.3-fold only after 5 generations The simulation results showed (I) that mosaic control with unrelated insecticides could retard resistance development in given conditions and (2) that it was extremely effective for monofactorical but little for polygenictraits. The strategies for resistance management are also discussed.

Key words: insecticide resistance——mosaic control——strategies for resistance mana- gement