Crop advice in strawberry/raspberry: start releasing beneficials on time

Spider mites can be really dangerous for strawberry and raspberry growers in open field, especially in the south of Spain and the north of Morocco – as the pest thrives under dry and warm conditions. According to Julien Mourrut-Salesse, Manager of Biobest’s Team of Sustainable Crop Management Specialists, this is usually the time to introduce the predatory mite Phytoseiulus persimilis – an efficient controller of spider mites. The release should happen when growers have detected the first spider mite hotspots in their crop, as persimilis can only develop when spider mites are already present – it is a curative strategy. Julien’s advice in a nutshell: “Monitor carefully, respond immediately when hotspots appear.”

Another enemy of strawberry and raspberry plants is thrips. Julien’s main recommendation is to release the predatory bug Orius laevigatus. “Orius gives the best control of thrips. It’s the only beneficial that also attacks adult thrips and that is able to clean-up a heavy population.”

Orius needs a few weeks to install itself on the crop. Introductions should start as soon as the average day temperature (24h) stays above 14°C. Orius can feed to some extent on pollen, while thrips is absent. A good installation can be further promoted by feeding NutrimacTM in release points. During the installation phase of Orius, weekly introductions of Amblyseius cucumeris can be used to provide immediate protection against thrips invasions.”