Transgenic Bt potato and conventional insecticides for Colorado potato beetle management: comparative efficacy and non-target impacts
Authors: Reed, G.L., Jensen, A.S., Riebe, J., Head, G., Duan, J.J.
Journal, Volume, Year: Entimologia Experimentalis et Applicata, volume 100:89-100, 2001
Field studies conducted in 1992 and 1993 evaluated the efficacy of transgenic potatoes (Cry3Aa), a microbial Bt formulation, and conventional insecticides (phorate and disulfoton, permethrin) against Colorado potato beetles (Leptinotarsa decemlineata). Microbial Bt was not as effective at CPB control, nor were the insecticides. Biweekly beating cloth samples were taken for 2.5 months to monitor populations of non-target pests and beneficial insects. The Bt treatments had significantly higher populations of beneficials and also secondary pests than permethrin. The permethrin treatment had significantly higher numbers of the green peach aphid. Phorate and disulfoton reduced numbers of plant-sap feeding insects, but did not seem to impact major predator populations.
Good study with a thorough field design. Good sampling for nontargets arthropods. It is important not only to analyze the effects of Bt, but to compare the effects of Bt products to the conventional insecticides they would be replacing.