Diptera‐dominated generalist pollination systems in <scp> <i>Eurya japonica</i> </scp> and <scp> <i>Eurya emarginata</i> </scp> (Pentaphylacaceae)

Abstract We investigated the flower visitors and floral traits of two dioecious shrub species Eurya japonica Thunb. (Pentaphylacaceae) and Eurya emarginata (Thunb.) Makino in temperate Kochi and subtropical Okinawa in Japan during the cool seasons. We demonstrated that the two Eurya species could be pollinated by a wide spectrum of flower visitors—mainly Diptera. The main pollinators were probably Chironomidae and Empididae for E . japonica in Kochi and Calliphoridae and Syrphidae for the remaining species–site combinations (i.e., E . emarginata in Kochi, E . japonica in Okinawa, and E . emarginata in Okinawa). We demonstrated that several dominant families of Dipteran visitors have the ability to pollinate the two Eurya species. Interestingly, floral traits (corolla diameter and nectar concentration) could not explain the difference in the assemblages. These results indicate that floral traits are not specifically adapted to their local pollinators. The fruit set rate was significantly lower for naturally pollinated flowers than for hand‐pollinated flowers, indicating pollen limitation in both Eurya species. However, there was no apparent difference in the number of seeds per fruit between naturally pollinated and hand‐pollinated flowers.