Winter Beekeeping Challenges: Managing Colony Losses

Audio (podcast version) is here

When you look at what would be expected to happen in a stable population of ‘wild’ honey bees, such as those in the Arnot forest, it is initially quite shocking how much death there is in nature. She is a harsh taskmaster, and it is not always the fittest that survive; luck plays a part too. As a beekeeper, I expect to keep my winter losses quite low – maybe 10% or less – but the Gods are not always smiling on me. This year, I have significant winter losses already, hence Winter Beekeeping Challenges: Managing Colony Losses.

Death In The Wild

Studies indicate that so called ‘wild’ bees swarm frequently, which is not surprising, as it is how bees reproduce. A species that is reluctant to reproduce is not going to do very well. I think that it would not be unreasonable to suggest that 70% of wild honey bee colonies swarm each year, and that only about 25% of those swarms survive. The parent colonies are left with queen cells, which means that not all of them will survive either. Most probably do, but there will be mishaps that leave the colony without a mated queen. There’s a lot of death going on. But, of course, there is a lot of new life too. There is a high churn, which no doubt helps with adaptations to environmental changes.

I try to raise queens that are very different to wild bees. Hopefully, they will be much less likely to try to swarm, and if they do try, I will deal with the situation before it happens. I can also keep an eye on parent colonies and re-queen if necessary. All being well, there is less death, and the new life comes from selected queens that display the traits that help me to produce lots of honey.

Winter Preparations

Another tick in the beekeeper box, a feather in my cap, or string to my bow, is that my bees go into winter with low varroa mite numbers and with plenty of stored food. This is the way¹. Well, it should be. However, something is afoot this winter. I have just finished trickling VarroMed (an oxalic/formic acid treatment) onto my bees in hives (I don’t do it on my nucs) and have been assessing the strength of all colonies. Many of the nucs are looking lovely, but on my production hives I have already lost 16%. It’s not starvation, and I don’t think it’s varroa. I think something went wrong with some of my queens.

Poor Queens Early On

I have twice as many strong nucleus colonies as those which died, so my hive numbers will still be continuing on an upward trend next season, even from springtime. Nevertheless, I am a bit depressed about losing colonies already. The way I make sense of it, at this stage, is that the first few batches of queens that we made in 2024 were not made under ideal conditions. The larvae that we grafted early on were a bit too dry (they should be swimming in jelly) which led to a lower take than normal. Then we had appalling weather which would have delayed mating flights. These two things probably conspired to produce some queens that were a bit rubbish.

Summer Queens

Later on, in the summer, conditions were good for making queens, and the bulk of those that we made went into nucs for next season. This may be why I have plenty of strong nucs, but some of the production colonies that I re-queened have died. About half of my “deaths” are not actually dead yet, but they are so small and pathetic that they will be dead by the spring. On the other hand, many of our surviving colonies are looking fantastic; it’s rarely all doom and gloom.

If we didn’t make queens and take plenty of nucleus colonies through the winter, then the odd bad year for losses, such as due to really harsh conditions, would set us back. That’s not happening to this walrus. Not only is queen rearing incredibly interesting and fun, it helps to keep beekeeping sustainable².

Death In The USA

On the subject of losses, and death, I had to raise an eyebrow at the latest survey results coming out of the USA for honey bee losses. The Apiary Inspectors of America recently published preliminary results from the 2023–2024 US beekeeping survey: colony loss and management. A staggering 55% of managed honey bee colonies were reported as lost during the survey year (from April 1, 2023, to April 1, 2024). The running average over 13 years is 40%, which is already a seriously bad number, but 55% is ridiculous. If varroa was the primary culprit, it suggests a degree of resistance to amitraz³ (overuse or improper use) and possibly leaving supers on too long. Sometimes beekeepers go for a bigger honey crop but that means leaving varroa treatments until it’s too late, causing high winter losses.

I asked Mike Palmer about this; as in, what the hell are US beekeepers doing to have such terrible losses? He shared some USDA analysis of his colonies, which showed nothing amiss. His losses were 20-25%, and he reckons most were varroa related. That’s way ahead of the US average, but still a cause for concern, and it has been getting worse in recent years. He said, “We’re losing too many good colonies for no explainable reasons.” The USDA analysis of his hives showed low varroa and low levels of deformed wing virus (DWV).

Mass Movement Of Bees

Mike reckons the problem in his area is partly to do with the mass movement of bees in the USA. There’s the almond pollination⁴, of course, in which most of the honey bees in the country can mix with each other and exchange any nasties. He also gets an “invasion” of bees from southern states in the summer, which bring with them countless mites and hive beetles. He can tell when the invasion has started because suddenly mites and beetles appear as if from nowhere.

Environmental Issues

The other concern is a gradual build up of pesticides in the environment, which has begun to cross a tipping point, such that queens are now being superseded more often and not being mated properly. Such things also damage the immune response in honey bees, making them more vulnerable to everything. Mike had some pollen tested from his hives and had 10ppb Clothianidin⁵ found in some samples tested by Cornell University. Dandelion pollen had 4.5ppb even though dandelions are not treated, so it’s in the soil. It’s unfortunate that things have to get really bad before there are changes to policy.

Mike says, “We’ve got an anti-neonic bill passed in Vermont. It won’t take effect until 2029. The product remains in the soil for up to 15 years. I’m 75, and I doubt I will ever see any benefit from the new law.” So, with that in mind, things don’t seem too bad in my apiaries, and I can’t wait for spring.

Notes

1. The phrase “This is the way” from The Mandalorian serves as a mantra or creed among the Mandalorians, particularly those belonging to the Children of the Watch. It underscores their dedication to a strict code of conduct, their cultural traditions, and their unique way of life.
2. Sustainable beekeeping is a term that is widely used to mean all manner of things. I am using it in the way described by Michael Palmer in his lecture at the National Honey Show in 2013.
3. Amitraz strips (e.g. Apivar) are effective if used properly and rotated with other treatments such as organic acids or thymol. At least, they are for me. Being lazy and leaving strips in the hive over winter is a great way to allow resistance to develop.
4. The almond pollination event in California is the largest managed pollination effort in the world. It occurs annually during late winter and early spring (February to March) in California’s Central Valley, where approximately 80% of the world’s almonds are grown.
5. While 5 ppb clothianidin may not cause immediate mortality, it has serious sublethal effects on behaviour, immunity, and reproduction, all of which contribute to long-term colony health decline. Managing and reducing exposure to neonicotinoids is critical to ensuring the survival and resilience of honeybee populations.