Functions of banker plants for biological control of arthropod pests in protected culture.

Abstract

Abstract Banker plant systems have been developed for the biological control of various pest species in protected culture. In such systems, non-crop plants, i.e. banker plants, are placed in the greenhouse and harbour alternative food and beneficials. The banker plant system is an effective strategy for biological control in greenhouses, with many benefits over the conventional release of beneficials. Moreover, they facilitate the reproduction of beneficials. However, the way banker plants function in this setting has not been clarified. The mechanisms of selection by beneficials between the banker plant, with its hosts or prey, and the crop plants, with its pests, is also not understood. The extent of selection of the banker plants by natural enemies may result in a lack of dispersal from the plants to crops and reduce pest control efficiency, because after selection of the banker plant, the natural enemy should disperse from it to the crop plant. There are many publications demonstrating the usefulness of banker plants as an alternative food source for the reproduction of beneficials. However, few publications have considered selection. Herein, we propose a theoretical basis for the banker plant system based on a consideration of its functions.