Influences of Botanical Pesticides and Biological Agents on Orius Laevigatus - Frankliniella Occidentalis Dynamics Under Greenhouse Conditions

Abstract

Influences of Botanical Pesticides and Biological Agents onOrius Laevigatus - Frankliniella OccidentalisDynamics Under Greenhouse ConditionsWe assessed the influence of nine biopesticides on adults and larvae of western flower thrips (WFT),Frankliniella occidentalis(Pergande) and its predator, the anthocoridOrius laevigatus(Fieber) under Mediterranean greenhouse conditions. Trials were carried out in a strawberry crop where both species had naturally established. Foliar sprays were applied weekly for one month. Treatments did not provide sufficient control of larval and adultF. occidentalis. The negative effects on the dynamics of the predator were evident only with the use of some specific products. The botanical insecticides rotenone and neem, and the nematodeSteinernema feltiae(Filipjev) reducedO. laevigatusnumbers, and these effect are evident in the adult stage ofO. laevigatus. Such products have determined a reduction of the population of the predator from the first treatments even if the incidence was not very high. We conclude that the use of some botanical pesticides and nematodes against WFT is uneconomical and possibly disadvantageous where there is an established predator-prey population.