Is Nocturnal Pollination Important for Crop Production? Experimental Evidence From Small Fruit Crops

ABSTRACT Insect‐mediated pollination is essential for crop production but is mainly studied considering diurnal pollinators only. Here, we use pollinator exclusion techniques to prevent either diurnal or nocturnal insect visits in small fruit crops: raspberry ( Rubus idaeus ), over 1 year, and red currant ( Ribes rubrum ) and black currant ( Ribes nigrum ), over 2 years, in sites within mixed landscapes of western and northern France. The contribution of day‐ and night‐active pollinators was measured from 850 flowers total from 36 plants across all species and included the following pollination components: fruit set, fruit weight, fruit volume and seed set. We find that nocturnal pollination improves seed set of all three crops, as well as fruit volume of red currant, compared to exclusion of all insect visits. This confirms the existence of nocturnal pollination services for these crops. We found no direct evidence of a nocturnal pollination service for fruit set of the three crops. However, we found that contributions from the combination of diurnal and nocturnal pollinators enhance fruit set in red currant and black currant. We found no effects of pollination treatment on fruit weight of any crop. These results suggest that nocturnal pollination plays a role in the production of small fruit crops, and call for inclusive pollinator‐friendly schemes including night‐active pollinators in order to support pollination services and crop production.