Vorblütebehandlungen mit Kaolin gegen den Gemeinen Birnenblattsauger (Cacopsylla pyri)

Summary in the original language of the document

The European pear sucker Cacopsylla pyri (L.) (Homoptera: Psyllidae) – one of the main pest insects in pear production – is commonly controlled by spraying broad-spectrum insecticides, which may have serious side-effects on beneficial arthropods. Recently, a new approach to fruit pest management has arisen in the form of processed-kaolin particle film technology (product name Surround® WP). The white kaolin particle film repels insects without killing them. Therefore, side effects on beneficial arthropods are expected to be low. This new approach triggered the present study to control C. pyri. In spring 2003 a small-plot field trial was conducted to assess the impact of pre-flowering kaolin treatments on the first generation of C. pyri. Multiple applications of kaolin after the beginning of the flying period of C. pyri were compared with an untreated control and the standard organic insecticide rotenone. Kaolin significantly reduced the number of nymphs compared to the untreated control and showed a higher efficacy than rotenone, with the triple application of kaolin the most effective. Due to the high mobility of the adult C. pyri the effects on the summer population could not be assessed in this small-plot trial. Therefore, a large-plot trial was conducted in 2004. Again, kaolin showed a very high efficacy. At the end of June 2004 few C. pyri were noticed in the kaolin treated plot but, the population density tended to be lower than in the plot treated by a standard IPM strategy (Envidor®, Evisect® S). C. pyri was kept under the economic threshold until harvest. Since kaolin repels insects, its effect on beneficials are low, and therefore might be an alternative control strategy for C. pyri in organic and IPM orchards.