FORUM Possible role of weaver ants, Oecophylla smaragdina, in shaping plant–pollinator interactions in South-East

1. Although theoretical models suggest that ambush predators could have a wide range of ecological and evolutionary effects on plant–pollinator interactions, these models require predators that are both abundant and mobile. Crab spiders, the main model system for studying the effects of ambush pre-dators on plant–pollinator interactions, are neither of these. 2. The weaver ant Oecophylla smaragdina is a keystone predator in South-East Asian forests. It uses the flowers of a wide range of native and introduced species as hunting platforms for incoming pollinators. Weaver ants affect the behaviour of flower visitors and the reproductive success of their host plants. 3. Due to their ubiquity and mobility, O. smaragdina ants satisfy the assumptions of the theoretical models. They have the potential to affect the structure of pollination networks. 4. Synthesis. Oecophylla smaragdina in South-East Asia, and possibly other predatory ant species in African and American tropical forests, may play a key role in shaping the ecological and evolution-ary trajectories of plant–pollinator interactions. Key-words: ambush predators, ant–plant interactions, community ecology, crab spiders, determi-nants of plant community diversity and structure, plant–pollinator interactions, tritrophic interaction