Individual foraging, activity level and longevity in the stingless bee Melipona beecheii in Costa Rica (Hymenoptera, Apidae, Meliponinae)

Foraging behaviour of individually marked workers of Melipona beecheii (Mel iponinae) was monitored in Costs Rica to investigate individual specialisat ion for different materials and how this influences foraging longevity. The majority of the individuals harvested one commodity (pollen, nectar or res in) during a single day. Half of the age-marked foragers specialised on nec tar or pollen during their complete foraging career, the other half collect ed two or three commodities. Most members of the latter group switched dail y from early morning pollen (or resin) collecting to nectar collecting. Lif e-long foraging of one-material collectors was not more efficient than that of two-material collectors. The groups of foragers differed significantly in activity patterns and longevity: activity was traded off with longevity. Nectar foragers were active all day and died after an average of 3 foragin g days. Pollen foragers were active for 1-3 hours per day, but lived for 12 days on average. However, pollen foragers and nectar foragers performed a similar number of flights in their career. How bees become pollen, nectar or mixed foragers is not clear Age and perfo rmance of pre-foraging hive tasks did not influence forager specialisation in M. beecheii.