Queen Bees: How They Mate, Store Sperm and Lead a Colony
A queen bee may mate during only a brief period of her life and store enough sperm to fertilize eggs for years. Discover how queen reproduction works and what scientists are learning about queen failure.
At the center of a honey bee colony is one extraordinary bee.
The queen.
She's usually the colony's primary reproductive female, capable of laying enormous numbers of eggs and producing the workers and drones that make up the next generation.
But one of the most remarkable things about a queen bee happens near the beginning of her adult life.
She mates during a relatively short period — then can store sperm inside her body and use it to fertilize eggs long afterward.
What Does a Queen Bee Do?
Despite her name, a queen bee doesn't "rule" the hive or give workers commands.
Her most important role is reproduction.
A healthy queen can lay large numbers of eggs during periods when the colony is growing rapidly.
She also produces chemical signals that influence colony organization and help workers recognize that a functioning queen is present.
Without a productive queen, a honey bee colony can eventually face serious problems.
How Does a Queen Bee Mate?
After emerging as an adult and reaching sexual maturity, a virgin queen typically leaves the hive on one or more mating flights.
During these flights, she can mate with multiple drones.
This genetic diversity is valuable to the colony because the thousands of worker bees she eventually produces can have different fathers.
After mating, the queen returns to the colony and begins transitioning into her primary role as an egg-laying queen.
Where Does a Queen Bee Store Sperm?
Here's where queen bee biology becomes particularly remarkable.
Inside the queen's abdomen is a specialized organ called the spermatheca.
After mating, sperm is stored inside this organ.
The queen can maintain viable sperm there for an extended period and use it gradually as she lays fertilized eggs.
That means mating and reproduction don't need to happen at the same time.
A queen can mate early in life and continue using stored sperm long afterward.
How Does a Queen Decide Which Eggs to Fertilize?
Honey bees have an unusual reproductive system.
When a queen lays an egg, it can be fertilized using stored sperm or left unfertilized.
Fertilized eggs generally develop into females, which can become worker bees or, under the appropriate conditions, queens.
Unfertilized eggs develop into males, called drones.
So the queen's stored sperm is fundamental to the colony's ability to continually produce new workers.
What Is Queen Failure?
Beekeepers sometimes use the term queen failure when a queen can no longer perform her reproductive role adequately.
There isn't one single cause.
Problems can involve poor mating, reduced sperm viability, disease, age, injury, environmental stress, or other biological factors.
Beekeepers may notice warning signs such as an abnormal brood pattern or changes in the types of eggs being produced.
If workers detect that their queen is failing, the colony may attempt to replace her by raising another queen.
Scientists Are Studying What Causes Queen Failure
One particularly interesting area of research involves the queen's spermatheca.
Researchers led by Alison McAfee investigated whether molecular changes associated with different stressors could be detected in queens.
They exposed queens to stressors including extreme temperatures and pesticide treatments and then examined proteins associated with their reproductive systems.
Different stressors produced different molecular responses.
That raised an intriguing possibility:
Could scientists eventually identify what happened to a failing queen by examining biological markers inside her body?
A Molecular Autopsy for Queen Bees
The researchers described an approach that functions somewhat like a molecular autopsy.
Instead of simply determining that a queen failed, scientists could examine biological evidence that might help reveal why.
The research identified proteins associated with particular stress conditions.
Researchers also examined failed queens provided by beekeepers and found molecular signatures consistent with some of the stressors investigated experimentally.
The work opened the possibility of developing better diagnostic tools for understanding queen health.
Why Queen Health Matters to Beekeepers
For a beekeeper, a queen isn't simply another bee in the colony.
Her reproductive performance can influence the future of the entire hive.
A strong colony requires a continuing supply of workers to forage, care for brood, maintain the hive, regulate its environment, and perform countless other jobs.
When queen performance declines, beekeepers may need to intervene or replace her.
Understanding why queens fail could therefore help beekeepers make better management decisions.
The Remarkable Biology Behind Every Hive
A queen bee's reproductive system is an extraordinary piece of biology.
She can mate with multiple drones, preserve sperm inside a specialized organ, and use it over an extended period to produce generation after generation of workers.
And scientists are still learning about the factors that influence her reproductive health.
It's another example of how much complexity exists inside something as seemingly simple as a beehive.
Every jar of honey ultimately comes from that remarkable living system — and from a beekeeper working to keep it healthy.
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