Preliminary study on insecticide resistance in Frankliniella occidentalis (Pergande) (Thysanoptera: Thripidae) in sweet pepper crops in Campo de Cartagena, SE of Spain

The resistance to more frequently used insecticides shown by two populations of Frankliniella occidentalis is compared by means of bioassays: one of them taken from a plastic-house without treatment against thrips and the other one from a plastic-house with monitored treatment. The difference between populations and its variation throughout time are discussed. At mid-season, when both the populations were treated with deltamethrin and chlorpyrifos-methyl no differences were found, although the populations from the plastic-house with monitored treatment showed resistance to acrinathrin, methamidophos, endosulfan and formetanate. At end-season the result was an increase in sensitivity of this population for all the tested insecticides, and the only case of resistance was to endosulfan.