Exploitation of pollen resources by Xylocopa splendidula in the Argentine pampas
María C Tellería
The pollen choice by native carpenter bees (Xylocopa splendidula) in the Argentine pampas was surveyed by means of the pollen harvest in nests. Samples were taken in January 1996, 1997 and December 1998. The data obtained were compared with data from introduced honey bees, Apis mellifera, in the same region (Tellería, 1993). 16 species belonging to 11 families of Angiosperms are present in the foraging spectrum of X. splendidula. The carpenter bees principally collected pollen from the plants which are isolated or in small populations. In contrast forage plants for honey bees are in dense populations. Such differences may be attributed to different skills needed to exploit the resources, and to displacement of native carpenter bees towards less productive environments, by introduced honey bees.