Anaxagorea crassipetala is a small understory tree of Central American lowland rainforests. As the specific epithet suggests, petals of the outer whorl are thick and fleshy having the general appearance and texture of little bananas. Floral brooding is commonly associated with obligate mutualism and with beetle pollination, but while a brood substrate is a large reward, competition for this reward may affect the reproductive success of all parties. In this case beetle mutualists compete for this limited and ephemeral brood substrate with non-pollinating fruit flies and beetles. While beetle pollinators only visit during anthesis, non-pollinating insects who oviposit prior to anthesis win the competition both with the mutualists and non-pollinating, floral-brooding insects who visit during anthesis. By experimentally denying access to pre-anthesis flowers, the reproductive success, as measured by fruit set, of the tree was significantly increased over open access controls. No mutualist beetle reproduction was recorded. This may be the result of a high rate of competition from fruit flies, whose feeding larvae may reduce the attractiveness of the petals as a brood substrate. Even among the fruit flies, oviposition prior to anthesis resulted in significantly higher reproductive success than ovipositions on the day of anthesis. Flowers were visited at a rate significantly higher than pre-anthesis buds suggesting that while ovipositing in buds increased fruit fly reproductive success, non-attractive buds were difficult to find in comparison to scent-producing flowers.

Key words: Anaxagorea crassipetala, Annonaceae, beetle pollination, competition, floral brooding, tropical