How to Recover from Colony Losses and Make Increase

Word has reached me through the beekeeping grapevine that colony losses this winter have been high, particularly in the South and East of England. Time will tell whether this plays out, but my information from certain sellers of queens and nucleus colonies seems to support that story. Pre-orders of queens and nucs are skyrocketing. My own small batch of over-wintered nucs were sold out within a couple of days of advertising. That’s only 11 nucs (pathetic, I know) but last season was difficult for me because of my house-move, meaning less time and energy for bees. Anyway, the point of this article is to look at ways of recovering from lost colonies and making even more of them than you had before.

High Losses?

Firstly, let’s consider why losses might be high. In fact, before that, what is “high”? For most commercial beekeepers that I know, losses of around 8–15% seem fairly standard, and anything above 20% would be thought of as “high”. David Wainwright has an interesting perspective on this, however. He says, “we have been taught that as bee farmers, we should be spending our time fixing struggling colonies and minimising stock losses.” He then goes on to state, “I have found that these struggling colonies rarely thrive, no matter how much effort we put into patching them up. They absorb a lot of labour costs and don’t produce much. So now we put all our efforts into starting healthy young nucs, and we leave nature to take her course with the struggling colonies. I would expect to lose 20 to 30% over a 12-month period, but these numbers would be more than covered by my fresh, young replacement stock. By this means my average honey production per hive is increasing each year, profitability is also increasing, and so I feel that the health of my ‘flock’ of bees is moving in the right direction.”

David’s real-life experience of managing thousands of colonies is worthy of note. To me, the important point is that despite such colony losses, his productivity per colony is increasing over time; his stock is apparently improving. From a commercial perspective, he has found that smaller, struggling colonies are not worth spending much time on. In fact, they are best removed from production sites to be replaced by vigorous young nuclei. It is a simple and effective method of stock improvement, assuming that the new stock is good. There is no re-queening (with associated risks and time taken) as the nucs are made using queen cells.

I must admit that I get a bit twitchy at the idea of losses of 20% plus, but that is probably a failing in me. It is often true that some colonies just don’t seem to ever properly get going, and messing about trying to feed/treat/re-queen or whatever largely turns to frustration. However, I have frequently seen small colonies that come out of winter and do incredibly well, with rapid expansion once conditions are favourable. So, I don’t think anything should be written off too quickly in early Spring, but if those small ones continue to lag, especially if boosted with bees and brood from strong colonies, then they are probably a lost cause.

By the way, a good trick for boosting a smaller colony in Spring is to swap its position with a stronger one. The majority of the foragers from the stronger colony will then ‘boost’ the small colony, bringing in forage, which may trigger the queen to increase her egg laying. In this way, we can give the queen who is suspected of being poor a chance to prove us wrong. Sometimes it works, sometimes not.

A Scenario

Right then, back to reports of high losses. In some cases, beekeepers have been nearly wiped out, but it’s too early for me to know how far this goes. If losses are worse as we move further South and East, then I would suspect that weather conditions will have played a big part. This is what might have happened:

• Colonies that went into winter with no mite treatment, or treatment that was only partially effective, had an early and warm Spring to ensure rapid population growth. A good Spring is a good thing, of course, but ideally colonies will be starting off with low varroa levels.
• The Summer brought long periods of very dry weather, causing nectar flows to be brief, with long dearth spells
• A lack of nutrition would have caused queens to stop laying eggs, leading to population decline and stress, which may have been accentuated by serious predation by wasps. Low levels of pollen result in weaker immune systems and increased vulnerability to viruses.
• Perhaps, by the time of mite treatment in late summer, the virus load was already critical for many colonies
• Supersedure may have been triggered, but queens and drones made in poor conditions are not great, so they could have failed in Autumn and Winter
• An increased number of ‘treatment-free’ beekeepers would have compounded losses both for themselves and neighbouring beekeepers (robbing of collapsed colonies)
• Beekeepers trying to eke out some sort of summer crop may have left treatments later than normal, to maximise anything coming in from balsam, or heather, or even ivy.
  

Given the number of wasps that were at large for much of the country last Summer, what many will find in their dead-out hives is very little because wasps will have cleaned them out. A lack of dead bees on frames and floor often signals a gradual dwindling, and at some point the vespas get in and strip the place bare.

All this is speculation, but if nothing else, it’s a scenario which could play out. What could have been done to help in this situation? There is little point in me going on about managing varroa because I’m always doing that, and some people simply don’t believe in it. But, managing varroa would save plenty of colonies. That means effective monitoring, followed by suitable treatment once a threshold has been reached. Things can still go wrong, but you have a better chance if you are proactive on the varroa front.

The other obvious measures would have been to feed the bees during the dearth periods, with pollen supplements and even syrup if needed. Oh, and making up late-season nucleus colonies to take through the winter (well-fed and treated for mites) would provide an insurance policy and a resource of bees ready to take off the following Spring.

People may have heard beekeepers say something like, “you can make honey or bees, but not both,” and I can see why that might be the case. There is always a tradeoff. However, when recovering from losses, I would be of the mindset to try to make more colonies and preserve my honey crop. “Madness,” I hear you say. Here’s what I would do:

Spring Splits

As we approach swarm season, and drones are about – so probably late April for me – remove frames of sealed brood from strong colonies, and use them to make nucs. I want four frames of brood per colony in my Langstroth hives at this time, so some colonies may have one frame removed, and others two, or none. Before making nucs, anything with less than four frames of brood would be boosted up to four first. The parent colonies keep the queen and most of the bees, so they continue to grow and hopefully make a honey crop, and don’t swarm. The stronger ones that have been slightly held back are the ones that would otherwise have swarmed.

The nucs are made up with two frames of bees and brood, the rest being drawn comb, stores, and foundation. They get a sealed queen cell from my queen rearing operation (sounds grand, but it’s not) and are moved to either a mating site or simply the site where I want to make increase.

When the last of the sealed brood has emerged, the colony is treated with oxalic acid to kill the majority (85–95%) of the varroa mites. Fourteen days after making up the nuc there will be no sealed brood, and maybe no brood at all, depending on whether the new queen is laying. Normally, she will be mated and beginning to lay eggs. One problem can be bad weather, which might delay mating by the queen. I don’t really want to be messing about disturbing the colony if the queen is still a virgin, but I will if I have to. If something goes wrong with the queen I can add another one, this time mated, after treatment.

Parent Colony

Removing one or two frames of sealed brood but leaving the queen will hopefully have put off any swarming intention by the parent colony. They will soon recover their strength and be in good shape for the nectar flows of May. Unfortunately, the impact on varroa mites will not be very great. If last winter’s treatment was not fully effective due to some sealed brood being present at that time, the mites will potentially get out of control during the summer. That’s why I like to do mite washes on all colonies in June. Anything over 2% is too high for me, which gives me a tricky situation – assuming I follow legislation (which I do).

Colonies with over 2% infestation in June will have to be dealt with because otherwise they will become overburdened with mites and deformed wing virus (DWV) by late summer. This is bad because (a) they will make less honey, (b) may die even if treated after summer harvest, and (c) could spread mites to neighbouring colonies. My current thoughts on this are to remove the supers and blast them with two pads of Formic Pro placed over the brood frames for 10–14 days. Often the pads are dried out and depleted before the prescribed 14-day treatment period is up. I can then return extracted supers and cross my fingers.

The image showing an output from Randy Oliver’s varroa spreadsheet model shows how this would work. I would still need to treat at the end of Summer, and again in Winter, to get the colony on course for the following season. I have assumed an 80% knockdown using Formic Pro, then 95% after the harvest using Apivar, followed by 85% effectiveness of the Winter oxalic treatment. These are in the right ballpark, and not excessively optimistic. There are risks to the ‘blast ‘em’ approach, such as queen loss, brood loss, and honey loss. However, I think it’s worth it.

The oxalic acid treatment of the previous winter now shows itself to be of critical importance. If done at the right time, production colonies are much more likely to have under 2% mite infestation in June, and can get on with making honey. If not, it’s a bit of a palaver.

Colonies that have very low mite numbers at the time of the June mite wash are worth noting. If they perform well in other respects, they could be headed by a queen that I would like to breed from. Some level of mite resistance is not my primary goal, but it makes no sense ignoring it either.

Late Season Nucs

Many of the nucs that I will sell in the following Spring are made up late in the season, after the honey harvest. This is to make use of all of those bees packed into hives once the supers are gone. There are plenty of ‘spare’ bees that can be shaken into nucs, given a queen, and fed. Hey presto, in a few months time, they are worth something like £300 each. Crazy.

It’s definitely worth taking some nucs into winter anyway, for my own use, to make increase or replace losses. That way, I am using queens made by me that suit my management and conditions.

Beekeeping is a game of probabilities, not certainties. Colonies will die, queens will fail, and seasons will surprise us. The only sensible response is to manage proactively, not emotionally. Monitor properly. Act early. Accept that sacrificing a super in June may save a colony in September. Make increase when you can, not when you are desperate. In the long run, the beekeepers who thrive are not those who avoid losses entirely, but those who plan for them.