Dual choice feeding tests were performed to verify a preference of forager honeybees for artificial nectars supplemented with various amino acids. Proline-containing nectar was preferred over a solution containing only sugars. Daily individual consumption was initially higher also for alanine-containing nectar, but the difference became not statistically significant afterwards. On the contrary, a negative response was found for serine. When the test was carried out with two nectars enriched with different amino acids, the same preference hierarchy was evident
