Nocturnal pollination of Parkia velutina by Megalopta bees in Amazonia and its possible significance in the evolution of chiropterophily

Abstract

Canopy observations of the rain forest tree Parkia velutina (Leguminosae: Mimosoideae) in Amazonian Brazil indicate that it is pollinated by night-flying bees. The small red flowers are organized into spherical heads; they open in the late afternoon and attract Megalopta bees (Halictidae: Augochlorini) which forage for pollen after dark. In contrast to the numerous bat-pollinated species of Parkia, no nectar was detected. Nocturnal melittophily is proposed as a possible intermediate stage in the evolution of chiropterophily from diurnal entomophily in Parkia.