Factors affecting resistance to insecticides in house-flies, Musca domestica L. (Diptera: Muscidae). I. Long-term control with bioresmethrin of flies with strong pyrethroid-resistance potential

Abstract

AbstractThe assumption that by minimising contact with pyrethroids, satisfactory control of Musca domestica L. could be retained without eliciting resistance was tested on a pig farm in southern England where permethrin had failed through rapid development of resistance. Flies were satisfactorily controlled in enclosed buildings for 12 months by space spraying bioresmethrin (2 mg a.i./m3) at approximately fortnightly intervals when numbers reached an arbitrary nuisance level. Throughout this period, bioassays revealed no increase in tolerance of pyrethroids, although selection experiments in the laboratory confirmed the strong pyrethroid-resistance potential of the fly population. Thus effective control can be retained in spite of strong resistance potential when non-persistent insecticides are used intermittently. The results are discussed in the light of a published theoretical study of the influence of pesticide persistence on the evolution of resistance.