Monday 24 February 2020

The Other Half Of Queen Rearing


There is a lot that's writen about queen rearing, an increadable amount, in books and on the web. There is so much that it can become confusing, trying to work out which method to use, how to select the best queen to breed from and how to set up a queen less cell starter, cell finisher or maybe a queen rite starter-finisher. Queen rearing texts or videos often end with a foot note: You should also raise drones. This aspect is the "other half of queen rearing" that can often be neglected.

Why are drones important then?

Bees are polyandrous, that is the queens will mate with numerous males, ten to twenty is often quoted as being typical. There is evidence though that the actual number may be much higher. Whatever the actual number is, there is conclusive evidence that the more drones a queen has mated with the more viable her colony will be. The worker bees will all have the same mother (their queen) but their father will be one of the drones with which the queen mated with. The colony will therefore be made up of a number of half sister groups. I increased genetic diversity within the colony helps them to be more resistant to disease and pests, better regulate brood nest temperature, gather more pollen and nectar... the list goes on.

It is therefore essential that the queen has enough drones available to mate with. A few days after the queen has emerged she will leave the hive on short orientation flights before embarking on her mating flight proper. These flights carry a great deal of risk, the queen may be lost, fall victim to a bird or dragon fly or she may be caught in a storm. She must run the gauntlet though to find suitable suiters.

If she fails to meet the required number of matings she must go out again and again until she is suitably mated. Each flight brings the same risks of being lost and so the odds of her returning decrease.

Honeybee love is a risky business! A 20% loss of new queens is typical.

Drone congregation areas

Drones fly to congregation areas (DCAs), typically less than three miles from their colony.
The queen generally flies further from her hive than drones do. This is how bees avoid inbreeding.

So how many drones does a queen need to ensure suitable mating? The drones spend time flying to the DCA, hangs around for a virgin queen to arrive, and if one does not arrive, or he fails to mate,  he must fly home, refuel and then fly back again. Clearly then there must be many more than the minimum of twenty to maintain a suitable population in the DCA. There are reports that a DCA will break up if there are fewer than 1500 drones in attendance. This is most likely controlled by pheromone concentration, which is what will attract the queens to the DCA too.

The Problem With Drones

Drone fertility is adversely affected by the miticides that we beekeepers use in our hives. This means that although our new queen will have found the required number of partners, she may be carrying some non viable sperm within her spermatheca.
A drone needs to mature before he is able to mate.
As he ages his sperm will loose viability.

The number of drones required for a mating yard servicing a number of new queens then should surely then be maximised.
BUT drones have a poor reputation. Historically they have been described as lazy, contributing nothing to the colony's honey crop, in fact they consume honey! A normal (natural) drone poplulation in a bee colony will provide some thermoregulation to the brood area freeing some of their sisters from the task, enabling them to move onto foraging duties a little earlier maybe.

Mites can preferentially breed in drone brood, the drone's pupation cycle better suits the breeding cycle of the mite.

For these reasons many beekeepers remove drone brood from their colonies once the cells are sealed, depriving the colony of their brothers and new queens of suitable mates.

Shouldn't we then, be allowing our colonies to raise drones?

Drone rearing is best done in strong well fed colonies, under similar conditions that  we raise our queen cells.

It is much easier to do than queen rearing though: We don’t need to graft or cut out cells, we just need to provide colonies with foundationless frames, (here) or drone foundation, which the bees will draw into drone comb.
Providing such frames has other benefits too, the bees won't have to steal space under or at the sides of a frame to build drone comb. You will find that the bees build much less burr comb!

By doing this we can select for both our queens and the drones with which they will mate. We are thus able to select or influence both male and female parents, hopefully producing better, well mated healthy queens that go on to head better, healthier and more productive colonies.
We are actively making use of both halves of queen rearing.


Thursday 13 February 2020

Check Your Hives' Weight

Winter feeding, why it's vital

Our bee colonies have been surviving on the stores that they were able to collect last season. Hopefully if you took off a good crop of honey, you left some for them and they were able to build on this with nectar from the ivy flow, the last main nectar crop of the year. We beekeepers should check each colonies' honey reserve before the end of the season and feed strong syrup to make up any shortfall. This is especially important for those late splits or nucs that we made up in the later half of the season. These  need a little extra TLC to enable them to both build bee numbers and also store honey for the coming winter. Building numbers requires food but collecting surplus food requires large numbers if bees! It therefore aids the colony if we provide supplementary feed during their development.

When winter arrives the bees are no longer able to find any meaningful quantities of nourishment, they are totally reliant on the honey that they have within their hive. During the cold months the queen lays very few eggs or stops altogether, the colony therefore doesn't have to maintain a brood temperature of ~35°C. The colony without brood can get by with a cluster temperature of ~10°C. Bees generate and conserve heat by forming a tight cluster and vibrating their flight muscles (wings disengaged). The fuel for this heat generation is of course the honey that they have stored. The cluster will move around the hive slowly consuming their honey. In early winter the heat needed by the colony and so the honey they consume is relatively low, the heat loss from a 10°C cluster is such lower than a cluster at 35°C.

As mentioned earlier a bee colony must be strong in bee numbers inorder to collect a surplus of honey. When spring brings the first major nectar flows from dandelion and tree blossom the bees must have a large number of foragers ready to exploit these resources. They must, therefore build up their numbers before the nectar flows arrive, they do this by gearing up brood production in the later months of winter.  In the UK in mid February......THAT'S ABOUT NOW! To do this they must raise the temperature of their cluster, maintaining ~35°C. This requires much more fuel (honey) and so their rate of consumption increases dramatically. The brood also needs to be fed, using up yet more honey! If they don't have sufficient honey stored away they are doomed to starve. 

That is unless we as beekeepers can step in to help. We should, especially at this time of year, be checking the weight of our hives by hefting, if we have the experience to judge the weight by feel, or if not then by using a luggage type spring balance to hive us an accurate weight. Any light colonies must be fed if they are to survive. This is almost always the case for colonies overwintered on five or six frame nucs, there simply isn't the room in a nuc to provide enough feed for the winter.

It is still too cold to feed syrup to the bees, the feed provided must bee in the form of fondant placed directly over the bee cluster. This isn't the cheapest form of sugar but is a good investment if you compare it to the cost of replacing a colony of bees.

So get out there, heft or weigh your hives and get that fondant on those colonies that need it!