Most of these insects may play a role in the pollination of sycamore. It is known to be a good pollinator of apple trees and might be an important pollen vector of sycamore.
Isolated trees carry regular fruit crops.
It is therefore possible that selfing occurs, pollinators travel long distances, apomixis occurs or flowers are wind-pollinated. Published evidence suggests that wind pollination is important. This section investigates the relative importance of wind and insect pollination in twenty trees at Murlough Bay, Co. Antrim. Out of a population of 37 trees, it was possible to select ten protogynous and ten protandrous trees bearing a large enough number of inflorescences close to the ground. The selection also included trees of contrasting flushing dates and varying exposure to wind.