SummaryMeasurements of blood juvenile hormone (JH), protein, and vitellogenin contents were carried out on adult queen honeybees during their first summer and winter and second summer, and with workers 12 and 25 days old. The JH titre was slightly higher in laying queens than in non-laying queens, but no higher than in workers.The titres of protein and vitellogenin were higher in queens than in workers, but no differences were obvious between laying queens and non-laying queens. No correlations were found between the titres of JH, protein and vitellogenin in queens. In both queens and workers the JH titre was positively correlated with age.