Colorado potato beetle (Leptinotarsa decemlineata Say) – control strategies in organic farming using biological insecticides (azadirachtin, Bacillus thuringiensis var. tenebrionis, pyrethrum and spinosad)

Abstract: Field experiments using different control agents for Colarado potato beetle controlshowed that all tested application strategies were effective. Time-shifted application of neem(NeemAzal T/S) and Bacillus thuringiensis var. tenebrionis (B.t.t.) (Novodor FC) as well asdouble treatment with B.t.t. achieved under optimal weather conditions gave an effectivenesslevel of over 80% and increased yields. Surprisingly, a single application of spinosad (SpinTor)also proved to be very effective (> 80%) in the three years studied in spite of the difficult studyconditions in 2009. Due to lower cost and a high efficacy of Spinosad it is likely farmers wouldprefer this plant protection product. Considering resistance of the Colorado potato beetle it isrecommended to change the insecticides every year.