Competition interactions among stingless bees (Apidae: Meliponini) for Croton yucatanensis Lundell resins

Abstract

Stingless bees use extrafloral resources such as resins for nest construction, defense systems and chemical communication. We conducted the first study of the resin-collecting process from Croton yucatanensis Lundell shrubs by three stingless bee species in the tropical deciduous forest of the Guanacaste Conservation Area, Costa Rica. We performed systematic observations on 10 C. yucatanensis shrubs for 10-min periods between 8:20 a.m. and 3:00 p.m. for three days, and for 90 min we focused on behavior and interaction among bees on three shrubs. Trigona corvina Cockerell was the most frequent visitor. These bees made cuts on shrub stems and leaves to collect resin and transport it in their corbiculae. Others visitor species were Trigona fulviventris Guérin and Plebeia frontalis Friese, which tried to approach the resin remains left by T. corvina. While monopolizing the resource, T. corvina behaved aggressively if approached by T. fulviventris. Towards the last hour of sampling, T. fulviventris visits increased notably, which may indicate a decrease in the dominance or aggressiveness of T. corvina at that time. This tendency seems to be the beginning of temporal resource partitioning behavior commonly observed in bee communities. We provide novel observations on the ways in which stingless bees collect resin and the interactions that occur among them. We also propose and discuss working hypotheses to explain the fact that all the individuals observed almost exclusively visited a single C. yucatanensis specimen.