Foraging Behaviour of Trigona Carbonaria (Hymenoptera: Apidae) at Multiple-Choice Feeding Stations

Abstract

To examine the foraging behaviour of the stingless bee Trigona carbonaria Sm., a full-size colony was placed at the centre of a grid of multiple-choice feeding stations with feeders containing water and three sugar solutions at 10, 20 and 40% concentration. The feeding of workers at feeders was monitored during consecutive days under these variable resource conditions. Scouts marked all the sugar-solution feeders with a visible fluid, and the degree of marking and nestmate recruitment was positively correlated with sugar concentration. Workers exhibited characteristics of the group-foraging behaviour termed 'opportunism', whereby many foragers search independently in the field, until one of them finds an exceptional sugar-solution resource and then rapidly recruits nestmates. Overall, workers preferred the 40% sugar feeders, visitation rates decreased with increasing distance from the nest, and visits at the 20 and 10% feeders increased in that sequence when replenishment with sugar solution was interrupted and sugar concentrations declined progressively in the 40 and 20% feeders. These results show that workers have the physiological ability to identify the richest sugar solutions, but indicate that food choice will vary with resource variability. The evidence suggests that the primary strategy involved in the foraging behaviour of this species is to optimise the feeding intake of the colony.