Attractiveness of exotic invasive plants can disconnect native plants from their floral visitors

Exotic invasive plant species (EIP) threaten ecosystem diversity and stability through competition for abiotic resources with native plant species. They can also compete for pollinators, as native floral visitors can incorporate EIP floral resources (i.e. pollen and nectar) in their diets, potentially shifting their foraging behaviour away from the native flora. To decipher how EIP attract native floral visitors and the potential competition between EIP and native plants for pollinators, we focused on five major exotic invasive plant species in Europe: Buddleja davidii , Impatiens glandulifera , Reynoutria japonica , Robinia pseudoacacia and Senecio inaequidens . We recorded in 16 sites in Belgium: 1) EIP floral visitors, 2) EIP pollen carried by these visitors and 3) pollen from native plant species on these visitors. We showed that bees were the dominant visitors and pollen vectors for Impatiens glandulifera , Robinia pseudoacacia and Buddleja davidii ; hoverflies were the primary visitors for Senecio inaequidens ; and non‐hoverfly flies, alongside bees, were the most frequent visitors for Reynoutria japonica. Senecio inaequidens exhibited the highest species richness of floral visitors, species richness of pollen vectors, and shared interactions with native plant species. Impatiens glandulifera exhibited the highest pollen transfer efficiency, with nearly 90% of its floral visitors carrying its pollen. While floral visitors of the other four studied species also interacted with numerous native plants, those of I. glandulifera carried its pollen almost exclusively, potentially substituting native species. These findings highlight how widely introduced exotic invasive plant species can integrate native pollinator networks to the point of disconnecting local pollinators from their original resources.