Global synthesis of apple pollination research highlights general pollen limitation and positive contributions of wild bees compared to honeybees

EERAERTS, MAXIME; OSTERMAN, JULIA ; BATÁRY, PÉTER; KLEIN, ALEXANDRA MARIA; ALBRECHT, MATTHIAS; ANDERSSON, GEORG K. S.; BÁLDI, ANDRÁS; BERNAUER, OLIVIA M.; BLECHSCHMIDT, LEAH; BLITZER, ELEANOR J.; BORGES, PAULO A. V. ; BOSCH, JORDI ; BURNS, KATHERINE L. W. ; CAMPBELL, ALISTAIR; CASTRO, SÍLVIA; COOK, JAMES M. ; DAELEMANS, ROBIN ; DANFORTH, BRYAN N. ; DE GROOT, GERARD ARJEN; DORJI, KINLEY ; FÖLDESI, RITA; GAINES DAY, HANNAH R. ; GARCÍA, DANIEL ; GARIBALDI LUCAS A.

JOURNAL OF APPLIED ECOLOGY

WILEY-BLACKWELL PUBLISHING, INC

Lugar: Londres; Año: 2025

0021-8901

Apple is one of the most important pollinator-dependent fruit crops worldwide. To secure high-quality yields, it is crucial to know which, and to what extent, pollinating insects contribute to itspollination success as measured by fruit set, fruit weight, and seed set.2. We perform a meta-analysisof field studies conducted across multiple sites on insect-mediatedpollination in apple cultivation, using raw data from 29 studies. We assessed the extent of pollenlimitation on different pollination outcomes and assessed the contribution of honeybees, wildbees and bee species richness to apple pollination.3. Across all studies, we detected strong evidence of pollen limitation for fruit set and seed set, butnot for fruit weight. Honeybees were the most abundant flower-visitors (average relativevisitation of 71.9% )compared to wild bees, but when correcting for their pollination efficiency,the relative pollination contribution of honeybees was lower compared to their relativevisitation (vice versa for solitary bees).4. We conclude that honeybee visitation rate did not influence fruit or seed set, yet increasinghoneybee visitation had a small, negative effect on fruit weight. Fruit set was not influenced bywild bee visitation rate, whereas wild bee visitation had a small, but clear positive effect on fruitweight and seed set. Bee species richness had a small, positive effect on seed set, whereas it didnot affect on fruit set and fruit weight.5. Syntheses and applications: Our study highlights that pollen limitation is common in this globalcrop. While managed honeybees are dominant pollinators, a diverse community of wild beescontributes significantly to apple pollination and high-quality yield. The positive effect of wildbees and species richness on fruit weight and seed set demonstrates that wild bee pollinationresults in better-quality fruit production (increased weight & seed set). Therefore, our synthesishighlights the importance of conserving pollinator diversity to maintain pollination services. Theabsence of a clear effect of honeybee visitation rate on fruit and seed set, coupled with its3negative impact on fruit weight, suggests a need for further optimisation of honeybeemanagement to improve the cost-efficiency of pollination management.