Bee Sex!

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Yesterday I attended the Autumn Cheshire Beekeepers’ Convention and Honey Show at Forest Hills Hotel in Frodsham. As usual I stayed for the two morning lectures, ate a hearty lunch fit for a walrus, and left. The speakers were excellent. It is so beneficial to go to these types of event whether one is just starting out or an old timer, and I always learn something. I also bought a book about bee diseases and something called “Candipolline Gold” (basically sugar paste with some protein in it) to feed to my nucleus colonies once they start raising brood early next year.

It seems a bit grim that there is so much focus on threats to honey bees, diseases, parasites, predators and so forth but although, as I pointed out in another post, honey bees are doing pretty well, it is the duty of every responsible beekeeper to get educated about their livestock so that they can identify problems early and take the necessary action. The new book contains many excellent colour photographs of delightful afflictions such as European Foul Brood and American Foul Brood, and so much more, including some nasties that haven’t arrived yet in this country, for example the small hive beetle. Part of my reading over the winter, when my bees are clustering and need to be left alone, is to prepare myself to be ready to spot any problems in my hives in the coming season.

The first lecture by Dr Giles Budge of the University of Newcastle and Fera Science Ltd was all about these threats to bees, and very well delivered it was too. The second lecture by author Celia Davis was about the mating of the honey bee and it reminded me of my fascination with drone congregation areas (DCAs).

It is strange we talk about the “birds and the bees” and sing about them too:

And that’s why birds do it, bees do it
Even educated fleas do it
Let’s do it, let’s fall in love

but not that many people really know that much about how honey bees…er…do it.

Fear not, the walrus is here to lift the veil. There is a great book by Gudrun and Nikolaus Koeniger called Mating Biology of Honey Bees which has the latest research on this topic. But in a few lines there now follows a brief summary of BEE SEX. There are exceptions, but this is how things are usually organised:

The Queen
Each colony has one queen and she is the egg layer for the entire colony. She holds many eggs inside her and has a handy spherical object in her lower abdomen called a spermatheca. Once she has had sex with male bees (drones) she will store some of their sperm in this organ and will use it to fertilise eggs as she lays them. Fertilised eggs make workers; unfertilised eggs make drones.

Drones
These are the sperm carrying males of the colony. Normally in summer there are about 2,000 of them in a colony whereas there can be 40,000 to 60,000 worker bees, who are the non reproductive females. Drones become sexually mature a couple of weeks after entering this world, and once they reach this stage their one and only ambition is to have sex with a queen. They don’t collect nectar or defend the colony or make wax or any of the other various tasks performed by workers. Their job is to get outside, find a queen, and get laid. It must be a miserable existence.

DCAs
The fascinating thing about bees is that mating occurs in certain distinct quite small areas called drone congregation areas. We don’t understand yet how they know where these DCAs are, but they seem to be born with the knowledge. Around lunchtime, perhaps after a picnic and bottle of wine, assuming it’s not too windy or cold, the drones fly out to these DCAs and wait for queens to arrive. The DCA is about 100 metres diameter and the drones are somewhere between about 10 to 40 metres high. I want to find the nearest one to my apiary because I think it would be an amazing thing to see. People who have studied these things have found drones from many colonies (over 200 colonies) in a single DCA, which ensures a great genetic diversity. Nature likes genetic diversity, it means that the species has a better chance to adapt to changes and therefore survive.

Mating
It turns out that drones tend to fly to the DCAs near to their hive whereas queens fly much further. This is another device to reduce the chance of a queen being mated by a drone which is closely related to her (inbreeding). There are about 10,000 drones hanging out in each of these aerial gentlemens’ clubs.

The queen has to get mated before she is about 5 weeks old, otherwise it’s game over and she will only lay unfertilised eggs. She flies out to her chosen DCA and upon entering it is immediately set upon by hordes of horny drones, who mate with her on the wing. The act is brief and explosive. Intercourse only takes about 2 seconds after which the drone’s penis snaps off, apparently with an audible “crack!” and the drone falls to earth and dies. Straight away the next drone is at it – he has to remove the penis of the previous chap before doing the business himself, and so it goes on. Within a minute the queen has been mated many times, about 14 on average, and back home she flies.

Aftermath
Quite a few queens won’t make it back, however. They get eaten by a bird or get lost and go to the wrong hive, which would result in being killed by the occupants. A study in Germany, where mating success of queens is closely monitored, showed that on average 26% of queens are lost on their mating flight [Tiesler 1972].

Once the queen returns to her hive the workers remove what’s left of the last drone. Sperm from all those happy but now dead drones who hit the jackpot will collect in the spermatheca and be mixed up. The sperm from each drone is represented in the mix. This means that the workers produced from the fertilised eggs have the same mother but different fathers. It’s that diversity thing.

Soon the queen starts laying eggs and that becomes her life. She won’t fly again unless they swarm, but that’s another story.

 

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