ABSTRACT:

The reproductive ecology of two species of Dieffenbachia (D. seguine [Jacq.] Schott and D. paludicola N.E. Br. ex Gleason) was studied at the Nouragues field station research in French Guiana. As in other known Dieffenbachia, the two studied species presented the classical cyclocephaline (dynastine scarab beetle) pollination system: Nocturnal anthesis with a strong odor, protogynous and short anthesis over 2 (3) days, female flowers being receptive on the first night and pollen being released on the second night. Inflorescences of D. seguine were visited by two species of scarab beetles (Cyclocephalini, Dynastinae): the dark brown Cyclocephala rustica and the black Erioscelis proba; while Inflorescences of D. paludicola were only visited by Erioscelis proba. Scarab beetles were efficient pollinators resulting in a high reproductive success even if some self-pollination can occur. Original data were gathered on flower and fruit predation leading to pollen and seed loss but their effect of the reproductive success still needs to be quantified.