Do environmental conditions exert an effect on nest-mate recognition in queen rearing honey bees?

Most studies of discrimination in the context of queen rearing have been performed in spring or summer, but the influence of environmental conditions on nepotism in honeybees has not received attention. Our experiments were designed to test the hypothesis that restricted resources influence honeybee workers to express a bias towards rearing related larvae more strongly than under favorable conditions. Three experimental designs were employed. In the first experiment, larvae were grafted using standard commercial techniques for rearing queens. Nurse bees were presented with sister larvae and alien larvae placed each in a cup, side by side in alternating positions. In the second experiment, nurse bees were offered the choice between sister or alien larvae placed in the same cup. The third experiment was similar to the first except that the objective was to harvest and weigh the accepted larvae and the remaining royal jelly. This study demonstrates that our colonies did not display nepotism in the context of queen rearing, whatever the season.