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An Annual Event
By: James E. Tew
Over and again
Oh, no! Not swarming – not again. How many times have you read articles or listened to presentations on the subject of swarming? How many times have I been given the topic? What else could there possibly be to understand about swarming? Well, bluntly stated, a lot. We are still in the lower levels of grade school in our education and understanding of swarming. (In fact, I suspect that we are still in the lower levels of grade school in our understanding of bee biology in general.) In this article, I make no claim to give you information that will promote you to the next grade level, but I would like to review the seasonal subject of honey bee swarming, but with an honest acknowledgment that swarming is complex far beyond our present comprehension. The 2026 swarms are coming.
An overview of the usual swarm episode
The typical event
The general story is that a colony – probably headed by queen that is more than one year old – comes out of Winter with a good population (What would you estimate – about 15,000 – 30,000 bees?). Swarming genetics is important, too. The brood nest becomes increasingly crowded. At some mysterious point, drone brood production is started by nurse bees and about 400-600 drones are reared. At the next mysterious point, nurse bees either build or modify queen cups into which the queen will – again mysteriously, deposit eggs. The swarming stage is set.
The swarm composition
At the next point – normally just about the time the virgin queens begin to emerge, the bees will “decide” who is to leave and who is to stay. While we still don’t know how bees get in the various categories, we do know that about half the bees go. In that half will be all stages of adult bees, some of the drones, and the old queen.
While the swarm is in transit, yet more mysteries abound. Swarms appear to move slowly – and they frequently do – but swarms can also move very, very fast. Slow swarm movers are usually headed for a temporary site where they hang for a few days while scout bees search for proper new nesting sites. Fast swarm movers (apparently) already know where their new home site will be and they move much faster. Either way, new nest site selection is a complicated subject about which we know little.
The new home site
At the new home site, the pioneers set about putting a nice new home together in a nice new neighborhood. Since they have no brood to feed, and since a nectar flow is usually underway, wax production and colony development occurs rapidly. The old queen begins prodigious egg production for the colony must have both bee and food resources for the upcoming winter. They can’t tarry.
A modification
Frequently, the old queen can’t maintain the frenetic reproduction pace and she begins to fall behind in her duties. In still yet another mysterious move, nurse bees begin supersedure procedures and new queens are developed. Some of these virgins emerge, fight it out (or are kicked out by house bees) until only one new queen remains. Somewhere along the way, the old queen is put out to bee pasture and the new queen takes charge of what is now a completely separate, functional, independent bee colony. Finally, after several months, the process of colony fissure is complete. A fairly simple story – right? No. I would like to return to some of the points and junctures and expand on what is happening within the colony before the swarm leaves the parent colony. Maybe next month, I will review the swarm in transit and the establishment of the new home site.
Non-swarming honey bees
Non-swarming bees ain’t gonna happen. Think about it. Colonies that don’t cast swarms are not going to multiply beyond the parent colony. Normally, beekeepers don’t want any swarms to issue. They lose honey crops, queens, and time/energy resources. Again, that ain’t gonna happen. Swarming is the honey bee species way of procreating itself. To ask a species not to multiply is a monumental request. Until super-science dictates otherwise, it stands that if you keep bees long enough, swarming will become an issue for you and your bees at some point.
Swarming bees
For eons beekeepers have chased swarms. In our recent beekeeping past, swarm acquisition was a common way for new people to begin an interest in beekeeping. Varroa changed all that, but that’s another article for another time.
Beekeepers who gather swarms – from anywhere – are also concentrating a strong swarming characteristic in their bee stock. While swarming can’t be stopped, it can be mitigated. Though very few of us do it, it would be a good idea to requeen new swarms with new queens and circumvent the whole swarm queen supersedure stage. I realize that only in a perfect bee would that routinely be done.
The swarming behavior may partially be the result of the evolution of absconding behavior or migratory behavior; otherwise, why does the old queen go with the swarm rather than the colony waiting around for the new queen to emerge and then go with her? It’s commonly said that honey bees have a tropical ancestry where migratory and absconding behavior are much more prevalent. Whatever reason, the behaviors of swarming, supersedure, and absconding have obvious characteristics in common.
The swarm queen
Back in the parent colony, in late Winter, brood production started with probably just a few hundred eggs; a leisurely pace. As the season progresses and spring pollen sources become available, that pace increases – dramatically. As things heat up, the queen’s retinue nearly doubles and she is constantly having food pushed her way. For the queen, it becomes an eating and egg laying frenzy.
The “balance” of the colony is always important – at any time of the year. As the brood begins to develop and as all the readily available worker cells are filled, drones and finally new queens are produced. All the while, the brood nest has truly become a happening place. Increasingly crowded and hot – new bees, old bees, drones, few empty cells, and Spring pollen coming in; the colony balance is threatened. Too many nurse bees with full brood food glands and not much to do with the food and, no doubt, the queen, that has been laying eggs at a prodigious rate has expanded beyond her ability to pheromonally suppress ovarian development in worker bees. The queen is abruptly put on a hard diet, but the colony has experienced the swarming stimulus. From this point on, the routine recommendation of adding abundant brood chamber space will no longer suppress the swarming response. The swarm switch has been triggered.
The queen must lose weight to fly – probably only the second period in her entire life when she will be outside the colony (other than to be assigned her final resting place). What triggers the reduced diet coming from the nurse bees to the queen? What level of reduction is enough? I don’t know, but reduction occurs and weight she loses.
Her abdomen shrinks and she becomes much lighter and mobile. She is treated brusquely by surrounding nurse and house bees. There is an air of excitement and energy throughout the colony.
To this point
To this point, at least four things have occurred within the colony:
- The colony has significantly increased in size
- The brood nest has become congested
- The worker age distribution has become distorted
- The transmission of queen substances has been diluted per individual bee
It’s elementary to say that swarming is a complicated issue when most things in beekeeping are complicated beyond our comprehension, but having said that, swarming is truly a complicated event. Two broad theories are still the foundation of the swarming instinct – (1) the brood food theory and (2) brood nest congestion theory. The problem is that neither theory completely addresses the swarm response. Clearly, brood food levels in nurse bees and congested brood nests are only part of the stimulus to swarm.
The genetics of swarming
This topic is beyond my grasp. As I write this for you – trying to digest the research work of others, it is as though there a colony newsletter or a colony public address system within the swarming colony. As I have said in other articles, inside the hive, it hot, dark, and crowded. It baffles me how individual bees – so many individual bees – are informed and assigned. They know what to do. Why doesn’t a queen that has been placed on a restrictive diet run around the hive searching for an uninformed nurse bee – one that would give the queen sustenance. Maybe she does that. Or why does the queen not feed herself? She’s not that helpless. She can go into any brood cells and find abundant brood food. Maybe it’s not the food she is craving, but at least it’s food. Certainly, honey and pollen are all about. As is most of beekeeping, it’s puzzling.
While brood food levels and brood nest crowding are clearly established tenets of swarming; they cannot be the only reasons. The genetic disposition to swarm (whatever that is) plays some role.
It takes a bee village
While I have spent much of my comments on the activities of the queen mixed with comments about brood food and colony congestion, it takes appropriate populations of multivariate aged brood, adult workers, drones, and queens. To this list must be added the requirement for abundant food resources. Food must be abundant within the hive and outside the hive or otherwise this discussion drifts toward either absconding or migrating behavior. For hive fission to successfully occur, many elements – both known and unknown must occur.
Eloquent vs. simplicity
“My colony is going to swarm (forget the academics) so I will clip off the queen’s wings. That should shut them down.” This describes an exquisite situation fixed with a practical solution. The 14th century Franciscan friar William of Occam wrote, “Of two competing theories or explanations, all other things being equal, the simpler one is to be preferred.” Occam’s Razor (The Theory of Parsimony) is established in the scientific literature. When we, as beekeepers, clip the wing of a queen, we are employing a modified version of this advice. Swarming is complex, confusing and costly. So, we do simple procedures like clip wings or add more brood space – neither of which solve the problem but may forestall the complex swarming event a bit.
What should you do to forestall swarming?
In this regard, little has changed since I last wrote about swarming – probably about this time last year. Essentially, you should add brood space well before it’s needed by the colony and, second, you should keep a young, prolific queen as the colony monarch. If you hive a swarm, requeening it before it either starts supersedure procedures itself or before it produces drone that would be carrying the swarm instinct, requeen it with a vibrant, new queen. Though it probably won’t help much, also providing adequate super space will not hurt. Bottom line: give space and keep the queens young.
What should you not do to forestall swarming?
I really don’t care for queen clipping, but I know many of you do it. The queen will still leave the colony and will hop along the ground. She may or may not get back to the colony once she has tried to fly. When one of the new queens emerges, the colony will probably swarm with her.
Tearing down queen cells is busy work also. If you really don’t want a colony to swarm, destroying a few cells won’t hurt, but it certainly won’t stop swarming either. Colonies with a high penchant for swarming will issue without any swarm cells at all; plus, you only have to miss one to allow the process to advance normally.
Caging the queen for a while – unless it’s really a long time – probably won’t help much either. Once the colony has undergone preparations for swarming, it’s difficult to change its mind. As with destroyed cells, some colonies will leave the caged queen and depart with one of the new queens (that may or may not be unmated).
They’re leaving
You’ve tried, but you’ve lost. Within the colony, on a warm day (probably mid-morning to mid-afternoon) workers within the colony begin tearing around the colony disrupting events and literally pushing the queen toward the entrance. The swarm begins to issue. At some point, the queen exits the colony into the bright light of day. While she doesn’t lead the swarm, her presence is vital to the swarm’s departure. At this point, the swarm is in the air. It’s a behavioral wonderment and I’m going to leave this swarm in this position until next month. Maybe it will cluster somewhere close to the ground. Until then.
Dr. James E. Tew
Emeritus Faculty, Entomology
The Ohio State University
tewbee2@gmail.com
Host, Honey Bee
Obscura Podcast
www.honeybeeobscura.com
