Abstract
The visiting frequency of flower-visiting insects was surveyed by interval timer shooting, and a pollination experiment,including inflorescence bagging and artificial pollination, was conducted to clarify the role of flower-visiting insects on the fruiting of black locust, which is a dominant tree species on the floodplain along the Tama River. As a result of interval shooting, 90% of flower-visiting insects were western honeybees. Interval timer shooting enabled to estimate insects visiting times, because the number of photos of honeybees obtained by interval shooting and the video-recorded time of honeybees were positively correlated with a high coefficient of determination. Bagging inflorescences and self-pollination resulted in a very low fruiting rate, indicating that black locust exhibits self-incompatibility. However, a significant correlation between honeybees visiting frequency and fruiting rate could not be demonstrated. Therefore, the low fruiting rate of black locust is assumed to be determined by a factor other than the visiting frequency of insects.
