Arquitectura de nidos y comportamiento de nidificación de la abeja Alepidosceles filitarsis (Vachal) (Apidae, Emphorini)

Abstract

Several females of the species Alepidosceles filitarsis (Vachal) were nesting in gravelly to sandy, well insolated soil, with scattered plants of flowering Portulaca cfr. equinosperma, from which the bees collected pollen. There was a single female per nest. In contrast to many Emphorini, the bees did not bring water to soften the substrate during excavation. The soil was excavated with the mandibles and pushed outside the tunnel with lateral movements of the abdomen and the hind pair of legs. The main tunnel was excavated at a right angle to the surface; it showed two or three lateral tunnels, at slanting angles, which leaded to series of cells. The deepest cell of a series might contain either the oldest or the youngest larva, suggesting that the direction of cell excavation was indistinct. Cells were provisioned with a ball-shaped mass of pollen. Eggs were laid on the lower side of the pollen mass. Foraging took place during the morning and midday, when flowers were open, whereas in the afternoon the construction activities were most important. The possible oligolecty of species of Alepidosceles on Portulaca spp. is reported.