*2.3. Royal Jelly Collection*

One month before the experiment, six honeybee colonies were prepared and populations were adjusted to maintain a constant number of worker bees in each colony. Empty combs were added to each colony and stimulative feeding was performed to maintain consistent worker bee ages and larvae numbers. Royal jelly was collected from the six colonies before the honeybees were fed single bee pollen; these samples were used as the controls. Traps were then set at hive entrances to prevent honeybees from carrying pollen in. The six honeybee colonies were randomly divided into two groups of three colonies each. Each colony was regularly and separately fed with equal amounts of BP-Am or BP-Pa to ensure normal royal jelly production. An artificial royal jelly collection frame was placed into the hive. After honeybees became familiar with it, larvae were transferred into the frame to induce nurse bees to secrete royal jelly into it. Royal jelly was collected from the frame at 72 h after larvae were transferred. Royal jelly samples were stored at −80 ◦C prior to further study.
