Despite the importance of cacao pollination services for global chocolate production, researchers know little about how cacao flowers get pollinated and set fruit. This is particularly true in regions where cacao originated. Identifying key pollinators and understanding how the location and management of cacao farms may influence visitations by these pollinators remain open research questions.
A recent article led by Justine Vansynghel, Ph.D. student in the Steffan-Dewenter Lab at the Julius-Maximilians-University (JMU) in Würzburg, Germany, addresses some of these questions. Professor Emily Poppenborg Martin of the Institute of Geobotany at Leibniz University, Hannover was among the international group of co-authors. Results from the study were published in the journal Ecological Solutions & Evidence.
The study, conducted in Peru, showed that aphids, ants, and thrips are important cacao flower visitors in the dry north of Peru, while thrips, midges, and parasitoid wasps are the most frequent visitors in the semi-humid south. While fruit set is higher with hand pollination (7% fruit set rate) compared to natural pollination (2% fruit set rate), both modes of pollination result in remarkably low fruit production. These findings warrant further research into other factors that could be limiting cacao fruit set, such as a lack of effective pollinators or genetic incompatibility among cacao plants.
The project was funded by the Federal Ministry for Economic Cooperation and Development of Germany and CGIAR.
