Synergistic effect of honeybees and wild floral visitors in promoting sweet cherry fruit set in central Chile.

Background: Recent evidence highlights the key role of wild insects as pollinators in agroecosystems, enhancing fruit set in crops such as sweet cherry (Prunus avium). In Chile, the contribution of wild insects to crop yield remains poorly understood, and most farmers rely on managed Apis mellifera or Bombus terrestris for sweet cherry pollination. Here we evaluate the role of wild and managed floral visitors' taxa in fruit sets of sweet cherry cultivated in Mediterranean-type ecosystems of central Chile.

Methods: The contribution of (i) Apis mellifera, (ii) wild insects, and (iii) Bombus terrestris floral visitors were analyzed using a Linear Mixed Model with visitation rate of each group as a fixed factor and a fruit set as a response variable. Orchards were included as a random factor.

Results: We recorded 24 species of floral visitors. Apis mellifera was the most frequent visitor, as the orchards supplemented pollination with beehives, followed by visits from wild insects and B. terrestris. Our results revealed that interaction between honeybees and wild insects significantly promoted higher fruit sets, while no effect of B. terrestris or A. mellifera visits alone was observed.

Conclusions: We argue that wild insects contribute to the sweet cherry fruit set in the Mediterranean-type ecosystems of Chile, complementing the pollination services provided by A. mellifera. Our study reinforces the evidence about the importance of promoting wild floral visitors' presence to enhance pollination and move toward more sustainable agriculture systems.