Experimental evidence of nocturnal pollination services for berry crops

Abstract

Insect-mediated pollination is essential for crop production but is mainly studied considering diurnal pollinators only. Using pollinator exclusion techniques to prevent either diurnal or nocturnal insect visits we estimate the contribution of day-active and night-active pollinators to fruit set, seed set, fruit weight and fruit volume in three berry crops. We find that nocturnal pollination improves seed set compared to exclusion of all insect visits for one crop (raspberry), confirming the existence and importance of a nocturnal pollination service. Moreover, we found a general pattern where best crop pollination resulted from combined services of diurnal and nocturnal insect visits. These results call for urgent consideration of nocturnal pollination in crop production and management, towards inclusive pollinator-friendly schemes including night-active pollinators.