Ornamental flower mixtures to attract pollinator and generalist predators

Summary in the original language of the document

Ornamental flower mixtures can provide food resources and habitat for insects, thereby contributing to conservation of pollinators and other insects, such as generalist predators. This report relates to three flower mixtures for private gardeners, created by a Swiss retail chain. The Research Institute of Organic Agriculture (FiBL) conducted an experiment to evaluate their ability to attract pollinators as well as three generalist predators by comparing them with a reference mixture. All flower mixtures were sown in raised bed boxes. These boxes were inspected biweekly for ladybugs, syrphid flies and lacewing, and weekly monitored for pollinators. In addition, the plant growth and flowering were recorded. The analysis concluded that the mixture 1, “Amber”, was the most attractive to ladybugs (P < 0.001), whereas mixture 2, “Bonnie”, was more effective than the other two at attracting pollinators (P < 0.001). The three mixtures were similar to the reference in terms of syrphid flies (P = 0.087) and lacewing (P = 1.000) numbers. The data suggest that ladybugs were attracted to mixture 1 due to the high number of aphids parasitizing Triticum dicoccon, combined with the low-rise plant Papaver somniferum which provided shelter for eggs and pupae. Since no single mixture was better than the others for all insect groups, I recommend commercializing them with labels indicating the specific groups they most effectively attract.