Results/Conclusions Visitation was primarily diurnal, ranging from 0.2 to 3.0 visits/flower/hour during the day, with between three and fifteen visitor taxa per species. Non-native visitors, mainly honeybees (Apis mellifera) and ants, were the most frequent visitors for most species. Hylaeus were infrequent visitors to three species and common only at S. chamissoniana. No native macroleptidoptera visitors were observed. Birds were the main visitors to S. glabra and S. procera, with the alien Zosterops japonicus a primary visitor to both, and the native Hemignathus kauaiensis also a main visitor to S. glabra. Visitors approached flowers in a manner conducive to pollination and/or to rob nectar. The interactions of the most frequent visitors with the plants differed for each species of Scaevola, and in several cases may impose limitations on pollination. The prevalence of alien visitors has several implications for both the plants and native pollinators. Non-native visitors may be depriving native pollinators of floral resources and may limit plant reproduction if alien visitors are less effective pollinators than native species. Alternatively, non-native visitors may provide important pollinator services for Scaevola species whose native pollinators have declined or shifted to new resources for unrelated reasons.