Floral visitors of the holoparasite Bdallophytum andrieuxii Eichler: A new report of brood-site pollination and thermogenesis for Cytinaceae (Malvales)

Bdallophytum andrieuxii is an endemic dioecious holoparasitic species belonging to Cytinaceae. Given the background of specialized pollination for the family and the genus, we explored the floral visitors of B. andrieuxii , describing the flower ecology of this saprophilous species. We found that flowers display thermogenesis, as their temperature was above the air temperature. Flowers produce nectar only at noon, in similar quantities and concentrations among both female and male inflorescences. Floral visitors belong to four functional groups: ants, carrion flies, flies, and butterflies. Their visitation peaks coincide with the moment of nectar secretion. Butterflies were the most common visitors, foraging male and female inflorescences, always touching sexual organs. We observed oviposition behavior and found eggs on floral tissues after butterfly visits. Lepidopteran larvae were found in all analyzed infructescences, feeding on floral and fruit tissues. Despite the larvae appearing to develop parallel to fruits and seeds, these insects did not affect the fruit or seed development. We conclude that B. andrieuxii have brood-site pollination by butterflies of genus Cissia in the studied population. The flowers display traits related to this pollination type: dark-colored flowers, a rotten-fruit smell, and thermogenesis.