Control of the woolly apple aphid (Eriosoma lanigerum Hausm.) by releasing earwigs (Forficula auricularia L.) and support oil applications

Abstract: The woolly apple aphid (Eriosoma lanigerum Hausm.) has been recognised as a serious pest in organic fruit growing where it may cause severe economic damage due to a lack of control strategies. Based on preliminary results a research project funded by the Federal Office for Agriculture and Food, Germany runs from 2007 to 2009 in cooperation with different research facilities in Germany to develop an on-farm strategy to control the woolly apple aphid in organic fruit growing. Earwigs (Forficula auricularia L.), as natural predators of woolly apple aphids,climb the trees when they turn into L3-Larvae in the end of May/beginning of June. By then the population of woolly apple aphid may reach high infestation levels. To control the woolly apple aphid until the earwigs appear in the trees oil applications were made in addition to the release of earwigs. We present preliminary results of the first and second year of the project’s field trials. They showed good efficacies for applying oil preparations by brush in the first year. The efficacy of releasing earwigs is inconsistent and depended on the infestation intensity. In the second year the trials have been expanded by a comparison of oil application by spaying and by brush in combination with releasing earwigs. On high infestation levels the oil application by brush proved to be more effective.