Colony noisy when opened; lack of apparent eggs; presence of emergency queen cells
A queenless colony is one that lacks a mated queen laying fertilized eggs. On rare occasions a queen may shut down egg laying for only a short time period (see queen shut down). The opposite of a queenless colony is a colony in queenrightqueenright:
a colony with a healthy, worker egg-laying queen; the opposite of a queenless colony
condition.
Queenless colonies will usually attempt to rear a replacement queen, a process termed emergency queen rearing. The developing queens originate from cells with fertilized eggs or very young worker larvae (one or 2 days old). Horizontal worker cells are modified to orient downward. Colonies usually rear several to many such emergency queen cells.
A hopelessly queenless colony is when there is no open brood for the workers to convert into emergency queen cells. Eventually, such colonies develop into laying worker colonies. Such colonies have what is described as a queenless colony roar—the pronounced sound of many bees fanning their wings when the colony is opened. Hopelessly queenless is difficult to determine, since a colony may be actively replacing their queen, yet this is not recognized by the beekeeper.
Just seeing a queen cell or cup does not necessarily mean that a colony is queenless. Colonies will make queen cells for many different reasons, and queen rearing can be aborted. When a queen cell is paired with a lack of brood, that is a strong indication that a hive might be queenless.
You can seek to introduce a new mated queen to an (apparently) queenless hive to make the hive queenright, but acceptance of a new queen (normally via a caged queen) is difficult.
queen shut down, emergency queen cells
Beekeeping Resources n.d. Non-infectious Diseases and Pests. University of Georgia Bee Program. Accessed 2023. https://bees.caes.uga.edu/bees-beekeeping-pollination/honey-bee-disorders/honey-bee-disorders-non-infectious-diseases-and-pests.html
Moore P. 2019. Honey bee queens: evaluating the most important colony member. Bee Health. Accessed 2023. https://bee-health.extension.org/honey-bee-queens-evaluating-the-most-important-colony-member/
The Apiarist. 2020. Queenrightqueenright:
a colony with a healthy, worker egg-laying queen; the opposite of a queenless colony
… or not. The Apiarist. Accessed 2023. https://www.theapiarist.org/queenright-or-not/