Jaarrond biologische bestrijding : onderzoek aan de modelgewassen gerbera en paprika

The PPS project ‘Year-round Biological Control’ focused on improving biological pest management unde r suboptimal climate conditions in gerbera and sweet pepper crops. In gerbera, the study investigated whether populations of predatory mites and predatory bugs, built up in autumn, could remain stable during winter and increase again in early spring. Their effectiveness against greenhouse whitefly was also assessed. Dicyphuserrans proved to be the most robust, while Orius majusculus and a cold-adapted strain of Orius laevigatus were effective when day length was extended using low-intensity blue LED lighting. Transeius montdorensis and Amblydromalus limonicus successfully controlled whitefly populations throughout the winter. An additional experiment showed that a one-hour night interruption with light enhanced early-year population densities of D. errans. In sweet pepper, early introduction of O. laevigatus during the propagation phase was tested to improve establishment. However, the benefit was limited due to a lack of alternative food on young plants. Early establishment of P-14 (Propylea quatuordecimpunctata) and Eupeodes corollae was also explored using banker plants. White LED lighting above banker plants particularly promoted P-14 population build-up on wheat bankers. Successful biological aphid control during the winter period was only achieved when day length was extended using LED lighting.