Ask a Master Beekeeper - August 2020

Supersedure: Nature’s way of requeening a colony

Requeening is a beekeeper’s universal panacea for all sorts of hive issues, from swarming to disease expression to overly-cranky bees. Sooner or later, you’ll be advised to requeen.

Some beekeepers routinely change out their queens in late summer every year in order to go into winter with a fresh, vigorous queen ready to go all out the following spring. Young queens who haven’t seen their first full summer season are reported to be less likely to swarm.

Most honey bees have remarkably short lives. In summer, worker bees wear themselves out in about six weeks of adult life. Winter bees, with a slightly different physiology and without the stress of having to forage, can live as many as five or six months. But queens can live for years. In the “old days” of beekeeping it was not uncommon to have queens live three or more years of productive life. These days, a typical queen’s lifespan often seems shorter. The cause for this is not known, but sub-lethal pesticide exposure and viral diseases vectored by varroa mites are believed to be factors.

The survival of the superorganism that is a honey bee colony depends completely on the reproductive competence of a single individual queen bee, among the tens of thousands of bees in the hive.

Given the staggering investment that a colony has in its queen, how do honey bees successfully manage to keep themselves productively queenright? Swarming is a way to double their genetic chances by dividing the colony into two (or more) separate units. The old queen departs with about half of the colony and a new virgin queen is raised and assumes responsibility for reproduction.

The other way a colony ensures that the queen in the hive is up to the task is to initiate a queen replacement process called supersedure.

What is a supersedure?

Supersedure occurs when the colony raises a few queen cells with the goal of replacing the existing queen. It differs from swarming in that there is no intention that the worker bees themselves will leave the hive. In supersedure, it is the queen who is changed, not the hive’s address.

Why does supersedure happen?

A healthy, laying queen produces a variety of chemicals called pheromones that act as powerful regulating and organizing signals within the colony. She is surrounded by a retinue of worker bees who attend to her needs, feeding and grooming her, and constantly licking her body. In this way, her pheromones are spread outward throughout the colony among all the bees as they feed and touch each other. These pheromones transmit such a vital message of security and coherence that their absence can be sensed in as little as 15 minutes.

But like all living things, queen bees age. And as she gets older, her reproductive capacity wanes and her pheromone production begins to change. The bees in the hive recognize this vulnerability to the colony’s survival and they set about to requeen the colony by themselves.

When is supersedure likely to occur?

Because a supersedure is not an emergency queen replacement process, like that which occurs if the existing queen is suddenly lost or injured, the bees can choose when to begin it. Once they determine that a new queen is needed, they are likely aware of the requirement for good mating conditions and the availability of ample, high-quality food resources to feed the developing queen larva. Mid-summer is a common time to find supersedures in progress. Sometimes packages will supersede their original queen if the bees feel the package queen isn’t up to a high-enough standard. Hived swarms may also supersede, as well as queens that have been in a hive for a year or two, even if they are apparently laying just fine. The bees will begin the process by preparing a few (usually just 1- 4) potential queen-raising cells.

Queen cells, swarm cells, supersedure cells, and emergency cells: how can you tell them apart?

There is no difference between an emergency cell, a swarm cell, or a supersedure cell, aside from the purpose. They are all queen cells and will have a more or less vertical orientation. When examining a frame, however, the location and number of cells helps to differentiate what’s going on. If you find only a few cells, and they are placed singly and only on the face of a frame, chances are you have a supersedure event in progress. If you find many cells, often dozens clustered along the bottom edges of the frames, even if there are also cells on the faces of the frames, it’s more likely to be a swarm. Both emergency cells and supersedure cells will appear on the face of the frames. But emergency cells are often smaller, twinned or crowded together. The biggest difference between emergency cells and a supersedure is that the existing queen is still cruising around laying eggs when the hive is superseding, while of course, she’s absent in the case of emergency cells.

What's happening during a supersedure?

The existing queen will lay a fertilized egg in each supersedure cell and the bees will feed the larvae the rich diet of royal jelly that turns them into queens rather than worker bees. Since the purpose of this is to wind up with a single replacement queen, the bees may not raise all the larvae to maturity, sometimes abandoning or tearing down completed cells. Once the virgin queen emerges, she doesn’t engage in violent mother-daughter competition. Instead, she continues to mature sexually for a few days. When ready, she flies out, mates and returns to begin laying eggs. At that point, once the bees are assured of having a reproductively superior replacement, the old queen’s days are numbered. She may be driven out of the hive, or just be attended to, and fed, less, until she perishes. Or she may be actively balled, or overheated, to death. There are also many reports of mother-daughter pairs of queens living amiably together in the same colony for some months, including through winter into the next spring. However the old queen’s fate is settled, the superorganism’s continued success has been protected. This is how the bees manage to requeen themselves.

What should you do if you discover your colony is superseding?

Unlike a swarming event where your interest in prevention may be urgent, a supersedure is best left to proceed without interference. The bees, experts at what’s going on in their colony, have likely picked a good time to raise a new queen and get her out and well-mated. And they still have the original queen as a back-up in case the new queen fails to return from her mating flights. If that happens, they may try again, or if it’s late in the season, wait until the following spring.

If supersedure is a natural process, does it ever indicate a problem?

Actually, yes, it can. Supersedure results from (among other cues) a diminished amount of the queen’s pheromone production. Normally this is a function of aging, but it can also happen as a result of disease, particularly Nosema disease. A single supersedure event with an older queen or in a recently-hived swarm (again, that’s an older queen) is nothing to be worried about. But a series of completed supersedures (supersedures where the queen is replaced, and then soon replaced, again) should alert the beekeeper of the possibility of other problems. Ironically in that case, the recommendation may be for the beekeeper to requeen the hive.