Floral scent and pollination of the invasive plant Coreopsis lanceolata in Japan

The invasive plant Coreopsis lanceolata threatens ecosystems in Japan by competing for resources with native plants. This species is self-incompatible and requires pollinator agents for seed production; however, it is known to produce many seeds. Here, we document the pollination biology and plant-pollinator interactions that facilitate seed production of C. lanceolata in the introduced range. Results revealed that C. lanceolata attracted a wide array of floral visitors comprising 60 species from 20 families. Although most floral visitors could be potential pollinators, the functional groups of halictid bees appeared to be the most important pollinators of C. lanceolata in terms of visitation frequency and the ability to carry pollen. The floral scent emission of C. lanceolata consists predominantly of monoterpenes, sesquiterpenes, and benzenoids. Furthermore, the mean seed set was nearly 30% of the ovule mean. Our study confirmed that in the introduced range in Japan, C. lanceolata is integrated into the local pollinator community, especially with the functional group of halictid bees involved in the reproductive success.