Hypopharyngeal Gland
Lexikon
The hypopharyngeal glands, also called the hypopharynx or brood food glands, sit in pairs in the head of the worker bee.
The hypopharyngeal glands, also called the hypopharynx or brood food glands, sit in pairs in the head of the worker bee. They develop in the first days of life and reach their peak activity roughly from the sixth to the twelfth day of life, exactly the period in which the bee works as a nurse bee. At this stage it produces a brood food rich in protein, fat, and vitamins, with which larvae and the queen are provisioned; mixed with secretions from the mandibular glands, this becomes the queen-feeding jelly known as royal jelly.
As the bee ages, the hypopharyngeal glands regress and switch their output to other enzymes that help process sugar and honey. This switch is reversible, however: if a colony suddenly lacks young nurse bees, for example after a heavy loss of house bees, even older worker bees can reactivate their hypopharyngeal glands and take on brood care again.
For practice it is crucial that every expansion of the brood nest, every formation of a nucleus colony, and every addition of open brood requires enough bees with active hypopharyngeal glands. If this potential is lacking, brood is inadequately fed or even removed again. A common mistake is looking only at the number of bees on a comb, without considering what proportion of them is actually at the right physiological age for nursing duties.