Evolution of worker sterility in honey-bees (Apis mellifera): how anarchistic workers evade policing by laying eggs that have low removal rates

In anarchistic honey-bee colonies, many workers' sons are reared despite th e presence of the queen. Worker-laid eggs are normally eaten by other worke rs in queenright colonies. Workers are thought to discriminate between quee n-laid and worker-laid eggs by the presence or absence of a queen-produced egg-marking pheromone. This study compared the survival of three classes of eggs (worker-laid eggs from anarchistic colonies. worker-laid eggs from no n-anarchistic queenless colonies. and queen-laid eggs) in both queenright n ormal colonies and queenright anarchistic colonies, in order to test the hy pothesis that anarchistic workers evade policing by laying more acceptable eggs. As expected, few worker-laid eggs from non-anarchistic colonies survi ved more than 2 h. In contrast, worker-laid eggs from anarchistic colonies had much greater acceptability, which in some trials equalled the acceptabi lity of queen-laid eggs. Anarchistic colonies were generally less discrimin atory than normal queenright colonies towards worker-laid eggs, whether the se originated From anarchistic colonies or normal queenless colonies. This indicates that the egg-removal aspect of the anarchistic syndrome involves both worker laying of eggs with greater acceptability and reduced discrimin atory behaviour of policing workers.