Some articles on royalactin:

Royal Jelly - Composition - Royalactin
... into a queen appears to be a single protein that has been called royalactin ... subject to decay and was fed to bees only jelly laced with royalactin caused the larvae to become queens ... Royalactin also induces similar phenotypical change in the fruitfly (Drosophila melanogaster), marked by increased body size and ovary development ...