BEHAVIOR AND POLLINATOR EFFICIENCY OF STINGLESS BEES AND HONEY-BEES ON MACADAMIA FLOWERS

Behavioural observations and experiments on pollinator efficiency of stingless bees, Trigona carbonaria, and honey bees, Apis mellifera, visiting flowers of macadamia, Macadamia integrifolia, growing in orchards in Australia were performed. Stingless bees mainly collected pollen and this activity resulted in intimate contact with the stigma. Honey bees mainly collected nectar and came into contact with the stigma less often. Racemes which were enclosed in cages which excluded honey bees but allowed visitation by the smaller stingless bees yielded a nut set equal to that on open-pollinated racemes, showing that these bees are efficient pollinators. Honey bees worked flowers more quickly than stingless bees, visiting more flowers in a given time. Both bee species responded to racemes rich in pollen and nectar by remaining longer at those racemes and visiting more flowers on them.