Controlling pollen beetles in Switzerland

Summary

Meligethes aeneus (pollen beetle) are a threat to oilseed rape. They migrate to the crops during the spring, damaging buds to feed on the pollen and nectar in the buds. In Swiss organic production as well as in Swiss IPM-production the use of insecticides in oilseed rape is prohibited. FiBL is developing an alternative non-insecticidal method to control pollen beetles. During migration, oilseed rape pests use volatile cues (signals given off by plants) to locate their host plants. This project is developing a control strategy for the pollen beetle based on repellent odors. By introducing odors to the field, the beetles find it much harder to locate their host plants. The project started with lab screenings of different essential oils, then, based on the two most promising oils, 21 different spray formulations as well as 16 different types of odour dispensers were developed, tested and analysed. Four different odor dispensers are currently being tested under on-farm conditions on organic oilseed rape fields in Switzerland. Claudia Daniel says “we are currently considering technical solutions, such application by drones, but there are still several obstacles to overcome. The input and feedback from farmers is especially important during this stage of project”