Structure and composition of the insect community associated with flower buds and inflorescences of Byrsonima verbascifolia (Malpighiaceae)

Abstract

The threat addressed to tropical biomes such as the Brazilian Cerrado leads to an urgent need for understanding the natural history of plant-insect interactions within ecosystems. Byrsonima verbascifolia is an evident Cerrado plant found to be economically and culturally important. This plant species is commonly found in that biome, showing a close association with insects since their flower buds and inflorescences contain attractive oil glands for a wide variety of them. In this study, we investigated whether communities of flower-visiting insects and ants associated with B. verbascifolia in the flower bud phase differ from those in the flowering phase. The abundance, richness and diversity of insect visitors to flower buds were similar in relation to inflorescences. However, low similarity of the composition of bud/inflorescence-visiting insects was observed. On the other hand, ants associated with plants in the anthesis phase showed a significantly higher abundance in relation to plants with flower buds, although the diversity was similar in both phases. Ant richness was higher in plants containing greater proportions of open inflorescences than buds, although this difference was only marginally significant. The ant community similarity in plants with buds and inflorescences was higher. Results suggest that different available resources (oil, pollen and petals) in buds and inflorescences of B. verbascifolia recruit a community of insect visitors with distinct composition, which was less affected in relation to the ant community. These findings show that visitors and ants do not use the same flower resource, once there are differences in terms of resources available in both flower buds and inflorescence stages.