Nestmate recognition was studied in the Neotropical
stingless bee Melipona panamica, a species in which
workers “sneak” their own reproductive eggs into 1% of
brood cells. We manipulated four factors that could influence
individual recognition cues: the mother queen, the environment
during the immature stage, the environment during the
early adult stage, and worker age. We also simulated the
action of natural enemies on colonies tested for discrimination
of such worker characteristics. All factors that we tested
affected responses of the discriminating workers, which
could recognize sisters, nieces and unrelated workers. Previous
exposure of unrelated callow bees to the odor of the
host nest greatly increased chances of acceptance by the host
colony. Probability of acceptance decreased, however, with
increasing age of introduced bees or increasing disturbance
of the host colony. These complexities in patterns of nestmate
recognition and nest defense are adequately explained from
the standpoint of inclusive fitness of the discriminating
workers. Differences in nestmate recognition and worker egg
laying among Meliponini are also discussed