Floral constancy in Trigona stingless bees foraging on artificial flower patches: a comparative study

Flower constancy is described qualitatively and quantitatively for stingles s bees (Apidae, Meliponinae). Flower constancy has been reported for variou s insects, but the degree of constancy seems to differ from species to spec ies. To test the hypotheses that the degree of flower constancy depends on colony size and foraging strategy, flower constancy was measured in three s pecies of stingless bees that differed in colony size and foraging strategi es. When the artificial flower types differed in colour or odour, most bees preferred one of the two flower types. On average, 77% of successive visit s were directed towards the previously visited flower type without major di fferences between the species. Constancy on odour was not generally overrul ed by constancy on colour or vice versa. When flower types differed in shap e, the majority of the bees visited the two types in a random way. Thus, di fferences in colony size and foraging strategy did not relate to flower cho ice performance in the Trigona species. The degree of flower constancy in t he stingless bee species studied was lower than that reported for European honey bees (Apis mellifera), but comparable with that reported for Asian ho ney bees (Apis cerana). We hypothesize that bees of tropical climates will be generally less constant than bees of temperate climates, due to differen t (environmentally imposed) optimal foraging strategies.