Spring is the busiest time of year for both the bees and the beekeeper. A strong, healthy colony will feel the natural urge to reproduce and will prepare to do so as soon as conditions are right. Swarming is how Apis Mellifera reproduces and is one of the first issues we face at the beginning of each spring.
As beekeepers, we need to know the signs of a colony preparing to swarm so we can prevent our colonies from flying off. This is not only to prevent the loss of our bees but because only about one in five swarms will survive. And if we keep bees in town swarm prevention is part of a good neighbor policy.
We should keep in mind that managing for swarms happens before the colony swarms and before you find swarm cells in the hive.
Swarming is nothing more than the natural goal of colony-level reproduction. If we are effective and responsible beekeepers we will work with bee biology (a knowledge of bee biology is key to being a successful beekeeper), by learning to identify the conditions that promote swarming. Beekeepers then take steps to manage the process.
If we wait until we see swarm cells then we are pretty late to the reproduction party. We need to be able to recognize the signs that suggest our bees are on the path to making swarm cells. There are two key signs. I’m seeing the two scenarios below in some of my colonies now. However in my own case it’s too early in the year to make splits, because there are not enough drones available yet with which a queen can breed.
You may be wondering why these things might be a problem. In short, they work to reduce queen pheromone in the hive. So let’s take quick side trip to learn about queen pheromones.
Queen substance or pheromone, is secreted by the queens mandibular glands. Queen substance, directly or indirectly, governs many colony activities. For example, it suppresses ovary development in workers and determines how aggressive or docile a colony may be.
Attendant bees in the retinue - the circle of bees caring for the queen - pick up queen pheromones by licking, touching or feeding her. They only remain with the queen for a minute or so and then move off, dispersing throughout the hive. Other nurse bees then move in to take their places and this cycle repeats continuously. The departing bees have some of the queen’s pheromone with them after ingesting it, while they were licking/feeding her.
Other bees in the colony make contact with former retinue group members moving through the hive and will solicit food from them (trophallaxis). During this meeting the queen’s pheromones are spread to other members of the colony. Studies have shown that, within the next 30 minutes, 50 or more other colony members will likely contact each of these former retinue members. These will spread the pheromone to even more nest mates.
Through this continuously repeating process most of the bees within the colony come into contact with the queen’s pheromones. The result is that a colony of 40 to 50,000 bees, most of whom will never have direct contact with the queen, are very much aware of the queen’s presence.
A colony will remain stable if it interprets the pheromone signals to be at a satisfactory level. A reduction in pheromone levels will trigger certain behavioral responses. Pheromone levels can fall for a number of reasons; the queen is old or diseased, poorly mated or has died for example.
Now let’s circle back to our discussion about how we know if a colony is preparing to swarm.
The colony will build emergency cells when the queen dies or is gone and supercedure cells when her scent is weak or she is failing. But in the spring a strong colony will prepare to swarm when the queen scent is reduced as a result of backfilling and full frames of capped brood. Their urge to reproduce will send them out to create a new hive as soon as the nectar flow comes on.
Backfilling takes place when foraging bees run out of empty comb in which to store nectar. They will first look to fill the area above the brood nest, but if they find it full they will store nectar in the brood nest. This area should normally be full of eggs, larva and capped brood, not nectar.
Along with the queen pheromone left on the eggs after the queen lays them, larva also produce a pheromone. These two scents tell the bees all is well and the colony continues to function normally.
But when the brood nest is backfilled with nectar and the queen’s egg laying space becomes limited then pheromone level drops.
When the thousands of bees in these frames emerge, the pheromone level found throughout the colony is diluted. Each bee experiences a lower exposure to the queen substance. The colony soon sees an entirely new generation of nurse bees, when there is a much smaller amount of brood for which to feed and care. Idle nurse bees contribute to the urge to swarm and bees of 12 days of age become terrific wax producers, which frees the earlier generation of nurse bees to forage or take on other chores.
The colony now has the makings of a swarm - strong numbers, plenty of food stores, reduced level of pheromones, lack of room for the queen to lay eggs and idle nurse bees. After building swarm cells, all the colony needs is a strong nectar flow and a warm day to leave the hive search of a new home.
The main event that begins the swarming process is a reduction in pheromone levels. Backfilling and full frames of capped brood combine to reduce the pheromone level and soon the bees will be building queen cells.
Also keep in mind that a beekeeper feeding a liquid feed can inadvertently create a similar situation, by providing more food than the bees have room to store in empty comb above the brood nest. This results in the brood nest being filled with sugar water feed.
Young queens have a stronger scent than an old queen which reduces the chances of queen cell construction. This is the reason it is often second year queens that the beekeeper sees swarming, though under the right conditions any queen can leave with a swarm.
You may have heard it said that drawn comb is a beekeepers gold. This couldn’t be truer when it comes to preventing swarming.
When you find backfilling of the brood nest - or even before that point - it’s time to add frames of drawn comb above the brood nest to create space for the bees to store nectar. Don’t be afraid of overdoing it. When the nectar flow begins bees can fill a box of drawn comb in a week.
Continue to add room to the hive as needed. You may just find you have the most magnificent honey crop by the end of the season and that means extra honey to freeze and then store for the following winter/spring. It also means your colony has stayed home, instead of leaving for the walls of your neighbor’s house.
So what happens when, in spite of your best efforts, the bees get ahead of you and the day comes that you find swarm cells in your hive? It happens to all of us and we should know how to react in a measured and thoughtful way.
The first thing to do is make sure they are indeed swarm cells. It’s possible to end up with a queenless colony if we make a mistake in identifying the queen cells we see. I know this from an experience I had as a beginner beekeeper. Check the location of the queen cells.
It’s important to positively identify the correct type of queen cell that you have. The time I ended up with a queenless hive was when they were building two emergency cells along the bottom of a frame and I scraped them off thinking they were swarm cells. Somewhere along the way I had inadvertently killed the queen and the only place they had to build queen cells was at the bottom of the frame. At least that’s where they chose to build them.
Another key in recognizing the difference is that swarm cells are typically built with newer, light-colored wax (light yellow). Modified worker cells are used for emergency and supercedure queen cells. and this old wax is dark in color.
So the three keys you are looking for are:
Do not think you can manage the swarming urge simply by scraping off the swarm cells. It’s easy to miss one and one is all it takes! Besides, bees will simply build more and that week you go on vacation, or were busy at work, BOOM - they will swarm and get away from you.
Once a queen cell is capped, normally about day nine, the colony can swarm at any time. If you find swarm cells before the colony has swarmed, the best way forward is to split the colony.
There are many different ways to split a colony (this is covered extensively in our Academy Course, accessible to Colony members). Here I will present two simple methods that are easy for beginners.
Before making a split there must be plenty of drones for the new queen. If you don’t see numerous drones in your colonies it’s not likely the queen will be bred well when she leaves on her mating flight. If you determine it would be best to wait, you can delay the process and buy yourself some time by scraping off the swarm cells. Remember, this won’t solve the swarming issue but may buy you some time.
If you live in a cold climate, like I do, you want to make large splits so there are enough bees to keep the brood warm. I suggest simply splitting a colony in half. In warm weather you can make more than one split from a large colony, but with the cooler spring nights as we have in Central Oregon a 50/50 split is best.
This method does not require the beekeeper to locate the queen. Bring a new bottom board, hive body, extra frames, inner cover and outer cover with you to the bee yard. Set up your new hive next to the colony you are splitting. Then simply split your existing colony in half, making sure that each “half” contains eggs for the bees to raise another queen.
Split the brood and the food stores as well, equalizing all resources between the two hives. Make sure the brood frames are put together in the middle of each hive. Sometimes, if it’s a large enough colony with eggs/brood in two boxes, you can simply remove one box with brood and place it on the new bottom board of the new hive and add the inner and outer covers.
You can leave the new hive in the same bee yard. The foraging bees will return to the “Mother” hive you split. The nurse bees will not leave the brood and are not yet leaving the hive so they will remain in the hive that does not have a queen.
I like to give these splits four days before returning to inspect them. In one hive with the queen you will find eggs and in the other hive without the queen you should find the beginning of queen cells. The colony raising a new queen should not be disturbed for a month. Make a note in your bee notes when the split was made and do not disturb the queenless colony for a month before inspecting it.
This method requires finding the queen. Remove the frame with the queen and place it in the new hive. Then add a couple more frames of brood covered with nurse bees. The colony you take them from now has more room, reduced numbers and no queen pheromone.
The bees will soon begin building queen cells to replace the lost queen and you have eliminated the stimulus that was causing the colony to want to swarm. You must make sure frames with eggs are left behind in the queenless colony and that there is a frame of honey and pollen stores moved into the new hive you are creating.
You can also make a split from a strong, populous colony and leave the queen in the original hive if you make the split before the colony builds swarm cells.
Some people like to make a split using swarm cells and some brood to make a new hive. Just keep in mind when using this method that you may be selecting for swarming tendencies.
It takes roughly a month for the queenless colony in any of the approaches above to raise up a new queen. You can install a purchased queen in the queenless hive after making the split if you do not want to wait a month. If installing a purchased queen I like to time the split so I make them up the day before the queen arrives in the mail, so the colony is queenless for a day and ready to accept a new queen.
Spring is a busy time and often brings the beekeeper new challenges and new fun things to do. An understanding of bee biology and a keen observation of the things taking place in your colonies can make your beekeeping experience more successful and enjoyable.
If you have never split a hive don’t be afraid to try and hopefully the information above will help you to do so.