Floral constancy in <i>Trigona</i> stingless bees foraging on artificial flower patches: a comparative study

Abstract

SUMMARYFlower constancy is described qualitatively and quantitatively for stingless bees (Apidae, Meliponinae). Flower constancy has been reported for various insects, but the degree of constancy seems to differ from species to species. To test the hypotheses that the degree of flower constancy depends on colony size and foraging strategy, flower constancy was measured in three species of stingless bees that differed in colony size and foraging strategies. When the artificial flower types differed in colour or odour, most bees preferred one of the two flower types. On average, 77% of successive visits were directed towards the previously visited flower type without major differences between the species. Constancy on odour was not generally overruled by constancy on colour or vice versa. When flower types differed in shape, the majority of the bees visited the two types in a random way. Thus, differences in colony size and foraging strategy did not relate to flower choice performance in the Trigona species. The degree of flower constancy in the stingless bee species studied was lower than that reported for European honey bees (Apis mellifera), but comparable with that reported for Asian honey bees (Apis cerana). We hypothesize that bees of tropical climates will be generally less constant than bees of temperate climates, due to different (environmentally imposed) optimal foraging strategies.