Queen honeybees are fascinating insects. If you’ve ever had to replace or introduce a queen into one of your colonies, you probably already know how this can be a delicate task. Bees are very protective of their hive, and they will reject a queen bee that is not familiar to them.
Honeybees use chemical signals that regulate many aspects of their colony. An essential role of these signals is to separate nestmates from intruders.
This works as the first line of defense that keeps non-nestmates outside in case they’re looking to harm or steal the resources they’ve worked so hard to gather.
These chemical cues are called cuticular hydrocarbons and are found in the fats in bees’ cuticles. As new honeybees emerge, they develop a hydrocarbon profile specific to their colony, recognizing them as members.
Additionally, the pheromones produced by the colony’s queen inform the other members of her presence and inhibits the production of a new one.
Consequently, a queen bee or any member of a different colony might be received with aggression when being introduced into a hive as they will be perceived as a threat.
Factors That Affect Queen Acceptance
It is no surprise that many beekeepers struggle to requeen a hive even if they are queenless and need a new mother.
Luckily, a few factors can make honeybees less likely to reject a new queen bee.
Time Of The Year Or Season
A study looking into the acceptance rates of queens in European honeybee and Africanized honeybee colonies found higher acceptance rates when queens were introduced during the fall.
In contrast, the lowest acceptance rates were associated with introductions made during summer. Researchers believe the amount of brood and the messages this can send to the other bees had something to do with this.
During the summer trials, the need for a queen wasn’t as urgent as later in the year when the egg-laying rate was already declining before requeening. Therefore, the bees were more open to accepting a queen.
Queen Compounds
The same study also found the compounds a queen releases can make her less susceptible to rejection.
More specifically, they found that queens with lower levels of E-ß-ocimene were more likely to get rejected. This compound seems to indicate how recently they have mated and the time they have been laying eggs.
Even though the compound levels in accepted queens remained the same throughout the year, the threshold at which queens get accepted might change.
Judging by the higher acceptance rates during the fall, it could be possible that lower levels of E-ß-ocimene during this season are more acceptable than during summer.
Mated Vs. Virgin Queens
Mated queens seem to have a higher chance of being accepted by a colony of honeybees.
This is not a surprise, given a mated queen would be ready to start laying eggs shortly after introduction saving the colony precious time.
However, there are a few reasons why this can be a problem for beekeepers in urgent need to requeen. Mated queens are usually more expensive, and in higher demand, so they are not always accessible.
Increasing Acceptance Of Virgin Queens
I found a fascinating study that looked into the acceptance of virgin and mated queens by introducing them directly with the help of smoke – the results are remarkable!
During this method of introduction, smoke is blown into the entrance before opening the hive. Once opened, 6 to 7 more puffs of smoke are blown onto the top of the frames. Once the workers leave the frames and gather on the bottom board and entrance, the virgin queen is introduced.
Seconds after releasing the queen, more smoke is blown into the hive, and after the queen disappears between the combs, the hive is closed.
As you can imagine, this method uses more smoke than you usually would during a regular inspection. Still, it seems to show high acceptance rates when introducing a queen to a queenless hive.
Other research has also pointed other factors that increase the chances of acceptance of virgin queens, like their weight. Those with higher body weight were better accepted than older queens with lower body weight.
Length Of Time The Colony Has Been Queenless
The same study mentioned above also found that the more time the colonies had been queenless, the more likely they were to accept an introduced queen.
Using the direct introduction with smoke, they found that after 5 or 6 days without a queen, the acceptance rate of virgin queens was 100%, while after only 2, 3, or 4, the acceptance rate was 85%.
The trend was similar when they used artificial cells as the requeening method. The queens were more likely to be accepted after 5 and 6 of queenlessness than after 2,3 and 4 days.
Signs Worker Bees Are Rejecting A Queen
Honeybees can detect and react to a new queen shortly after her introduction. As a result, they can start harming her in a matter of hours after emerging from the cage or the protective device used to requeen.
The reaction is so quick that even researchers consider a queen is accepted if she is still alive and well a day after introducing her.
When worker bees reject a queen, you will be able to tell by their behavior towards her. These are:
- Chasing
- Clamping or closing the mandibles on the queen’s legs or wings
- Biting
- A stinging motion towards the introduced queen
- Immobilization or clamping by various bees
- Balling, which most often results in the death of the queen
After releasing a queen bee, watch closely what the workers do around her. If you see any of the signs above, she’s likely been rejected by the colony and could be in danger.
Queen Balling
Most often, the introduction of an outside queen can end up in a phenomenon known as balling. This is when bees mount the newly introduced queen and tightly press against her generating enough heat to suffocate her to death.
Balling is not exclusive to honeybees, and it is used mainly as a defensive mechanism. Bees use this to protect themselves against known intruders and predators like wasps and hornets.
When studying signs that precede queen balling, researchers found worker bees persistently try to sting the new queen – not so much to cause harm but to mark her with pheromones that make her the target and leads to the balling action.
Pheromones And Queen Balling
By now you’re probably aware of the crucial role pheromones have in a bee colony. They seem to be involved in almost every bee behavior, including how likely they are to ball new queens.
Predictably, the famous queen mandibular pheromone could also be involved in this aggressive welcome to foreign queens.
While the pheromone released by worker bees causes the ball formation around the rejected queen, it is believed the queen mandibular pheromone indicates workers which queen is foreign and, therefore, the target of aggression.
Tips To Introduce A Queen And Avoid Getting Her Rejected
- Don’t be afraid to ask for help from more experienced beekeepers, especially if this is the first time you replace a queen in one of your hives.
- Make sure the hive is queenless and no queen cells are present to increase the success of the introduction.
- Leave the hive queenless for at least a full day (24 hours) before introducing a new queen. If you are replacing a living queen, you must locate her and extract her before introducing the new one.
- While fall tends to increase the likelihood of acceptance, make sure you also check the weather and the temperatures. It will be harder for you to open and inspect the hive to see if the colony accepts the queen as it gets colder. Therefore, it’s crucial to find a balance between the season and the weather. Otherwise, you could end up leaving a hive queenless soon before winter and with less time for the colony to grow and prepare for the cold. (Fewer bees –> weaker cluster in winter). Â
