Experiences in controlling resistant pollen beetle by type I ether pyrethroid Trebon 30 EC in Germany

Abstract

Oil seed rape (OSR) is an important crop in Germany with a long growing history. Due to the prevalence of various springtime pests an average of two pyrethroid applications are made. Pyrethroid resistance in Germany was found locally in 2003, widespread distribution of resistance was observed in 2006, a year of very strong pest pressure. Field trials in 2005 and the following years and laboratory analysis showed good control of resistant pollen beetle (Meligethes aeneus) by type I ether pyrethroid etofenprox, the active substance of Trebon 30 EC. Etofenprox differs significantly from common pyrethroids, which are usually ester pyrethroids including an α‐amino‐group and halogen substitutions. Trebon 30 EC has comparable efficacy on all important OSR pests but it has superior efficacy on resistant pollen beetle compared to common pyrethroids. To cope with pyrethroid resistance of pollen beetle, three different modes of action (MOA)s are postulated, which may be type I pyrethroids, neonicotinoids and organophosphates (OPs). Because type I pyrethroids, such as Trebon 30 EC, perform well at low temperatures, have a broad spectrum of activity, are considered as not to be toxic to bees, and give a high level of control of resistant pollen beetle, they will have an important role in the insecticide spraying regime of OSR.