COLOSS visits Oxfordshire

This article discusses a scientific symposium on Treatment Free (TF) bees, from the perspective of an amateur TF beekeeper.

Background

The Working Group at Worcester College, Oxford. Photo by Vincent Douarre. Click for larger image

Oxford recently hosted a couple of symposia by scientists researching TF bees.

COLOSS is an international network of 1967 honeybee researchers and stakeholders from 114 countries, originally formed in 2008 to address the issue of COlony LOSSes (pests, diseases etc). Its research influences policy decisions by governments and national beekeeping associations. One sub-group, the Survivors Task Force, focuses on honeybee populations that have evolved tolerance to varroa – and Oxfordshire has such bees. (Actually they’re widespread in Britain, but it’s about proving it.)

This Task Force held a 1.5 day meeting in Oxford, followed by a one day training session finding wild nests in Blenheim Forest. Members of our local TF group, OxNatBees attended both events.

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Summary

What struck me:

• I’d assumed the scientists would be rather unapproachable and exist in something of a bubble. Quite the reverse. They were enthusiastic and delighted to talk to non researchers. We’re the source of much of their data, if only we talk to each other. And they’re heavily dependent on non academic beeks to run the trials.
• One third of those present were not active research scientists (though most seemed to have PhDs). I thought I’d be the only one. COLOSS isn’t just academics.
• EU funding ran out years ago. This is a volunteer task force, funded mainly out of their own pockets, and run with enormous enthusiasm. They have an amazing “just do it” attitude.
• There was no confrontational attitude. This was a pooling of experiences and everyone respected everyone else.
• A huge variety of approaches are being trialled.

People

Twelve people were physically present and seven by videolink. We were from Australia, England, France, Germany, Ireland, Italy, Spain, Switzerland, and Thailand. The meeting was chaired by Arrigo Moro and Raffaele Dall’Olio. About half of us went to the Learning from the Bees conference a few days later.

Presentations and conversations

Raffaele Dall’Olio describes himself as a hybrid researcher / beekeeping trainer / consultant, transferring information between researchers and beekeepers. He gave a short introduction, explaining the background of COLOSS and this task force for newcomers.

At this point I hit a conceptual barrier. He described how one of COLOSS’ core projects is The BeeBook, which describes standard methodologies for researchers. I’ve glanced at this before and, as an amateur, found it very daunting. A typical procedure is removing a frame and examining it, followed by some very dense technical language specifying a precise method. However, I very rarely open my hives, to the point that many of my combs are attached to walls. They can be inspected but it’s disruptive. So I always assumed that COLOSS was for conventional beekeepers and people with skeps and other leave-alone hives would be ignored by them. Which is frustrating as we are seeing many TF tolerant colonies (more on this later). However, Filipe Salbany said something revelatory to me: any hive can have a super with inspectable frames put on top of it, even a log hive. This was like a lightbulb to me – maybe we natural beekeepers can contribute to these studies.

Raffaele did a presentation on the B-GOOD project, an H2020 EU funded Research and Innovation initiative to help beekeepers with remote monitoring of hives (sound / vibration, temperature, weight). The aim is to minimise inspection, but this is for heavily managed hives. I used to design electronic instrumentation and I found the remote monitoring technology rather impressive (reliable long term weight measurement is particularly tricky), but you can read about it on their website. The take-aways here for me were that they hit limitations like, you don’t have power for the instrumentation in the middle of a forest; the Finns stack hives in really high towers which rock in the wind, confusing weight measurements; beekeepers find the sound of a hive much easier to interpret with their ears than by looking at a graph.

The next generation of B-GOOD kit may monitor CO2 levels, count bees and do other stuff which sounds very expensive. More excitingly, they are also developing lateral flow tests to detect some pesticides (imidacloprid, acetamiprid, thiamethoxam) and viruses.

[Interesting coffee break conversation concerning pesticides:

Me: are extended tongues really a sign of poisoning or is it too ambiguous a symptom?

Arrigo: Not a reliable indicator. Poison effects are inconsistent because different ones have different effects, and it varies with dosage. And apart from neonics, they’re degraded by sunlight. So if you want to send a sample of dead bees to a lab make sure they have just died, because after half a day in the sun, the amount of poison is likely to be halved or less.]

Arrigo Moro is a veterinarian and second generation beekeeper who helped his father manage 400 hives, so tended to get sent to do the more challenging, interesting bee handling when doing his PhD on varroa genetics. He’s currently working at the University of Galway on free living bees, and helped set up Honey Bee Watch with Steve (see later).

Arrigo pointed out that COLOSS deals with populations of bees over large areas, and needs to work with commercial beekeepers all over the world. Whereas our local natural beekeeping group can use a “hard Darwinian” approach (let the weak die, propagate from survivors) because we aren’t dependent on income from hive products, most beekeepers need the income stream so need a “soft Darwinian” approach, such as gradually tailing off miticides and selecting bees from tolerant hives, to make their bees gradually more tolerant so their business doesn’t collapse from too many losses in one year.

I put it to him that deliberate selection / breeding narrows the genetic base and rather than selecting for one super-trait, which mites will inevitably adapt to, a better long term approach uses naturally evolved resistance which depends on a continually shifting mix of minor traits like grooming, propolising, hygiene etc. Mites can’t adapt to such a continually changing anti-mite regime. We concluded a mix of all strategies is best, accelerating mite resistance through selective breeding and the “black box” system I use where I don’t know why it works. As Arrigo said, his job as a scientist is precisely to figure out the Why.

Arrigo did a presentation on monitoring wild nests in Ireland. The University of Galway is coordinating a citizen science project and has mapped 379 nests so far. The participation model can act as a template for other projects / countries. An app helps with in-field data entry. They use large Zoom meetings three times a year to co-ordinate with the citizen scientists, the first one had 75 participants.

Steve Rogenstein founded The Ambeessadors (educating and promoting pollinator friendly practices) and co-founded www.HoneyBeeWatch.com with Arrigo and Raffaele. He gave a presentation on the distribution of known honeybee colonies. You can see a map online here, and if you wish to add more you can create an account to load locations in. GPS coordinates are deliberately masked by approximately 1 square kilometer, thus obfuscating exact locations and preventing bad actors from potentially destroying or trapping nests.

Wild nests mapped by Honey Bee Watch. Image (c) Honey Bee Watch

The slide here (distorted because I was sitting to the side of the screen) shows absolutely loads of wild colonies in Ireland, but also in Italy which surprised me. You can also see clusters of TF survivor colonies in England – around Oxfordshire, because the local natural beekeepers entered data. We know there are loads more around Britain and other countries; it’s a matter of getting the data. The point Steve is making here is that without data, the IUCN can’t declare honeybees to be a Protected species on its Red List (or not).

Honey Bee Watch also maps TF hives, and other types of bees like A cerana. It’s worldwide, but so far most data has been entered in Europe. It’s just hitting the inflexion point where the dataset is growing rapidly, to the point where it’s useful for strategic policy decisions.

One thing mentioned in passing which is a significant management issue, is coordinating with similar projects and importing data from other researchers. Intellectual property rights and privacy must be maintained. Imagine for example if you put your PhD data in as you gathered it, then someone else published a paper using it before you do. Or if you participated in a survey on the understanding your apiary locations would be kept private. This is why there is a large team working on the IT behind the scenes.

Spencer White and Maria Bru run natural beekeeping groups in Australia (The Colony) and Spain, so like me they were a little unsure of what to say among scientists. Operating in Australia, they also deal with A. cerana, solitary bees and stingless bees.

Matthieu Guichard is a commercial beekeeper, operating in Switzerland and France. He tried natural beekeeping in Warré hives for ten years but couldn’t make it profitable, so switched to conventional beekeeping and framed hives in 2017. He made the point that Switzerland has a huge density of hives (all crammed into narrow valleys) and people tend to use imported bees, and miticide use is compulsory if mite numbers are above a threshold, so it’s very difficult to keep survivor TF colonies pure, and the original Amm bees are pretty rare, swamped by Italian and Carniolan imports.

We enjoyed that his last name means European Hornet and mine means Honey Man.

He presented a paper titled Natural Selection to solve the ‘varroa problem’ – a SWOT analysis, co-authored with Benjamin Dainet and Vincent Dietmann.

This discussed the kind of beekeeping I do: hard Bond strategy, Leave and Let Die. About the only upsides of this approach he can see is that it’s fast, and if it works the results are better (healthier and stabler) than selecting a handful of traits.

However he listed several downsides:

• Success stories are rare (I dispute this – I think it depends on having a background of unmanaged wild colonies, which is why it works in Britain)
• The initial losses are too high for commercial beekeepers dependent on an income stream from hives
• If nest density drops too far the population is no longer self sustaining, as seen in the recent German beech forest study
• If the population crashes too fast, there will be a loss of alleles. (I.e. too much inbreeding leads to excessive sterile diploid drones, and the remaining colonies will collapse.) This can also lead to reduced resilience; the much studied Gottland colony numbers crashed when varroa arrived and never recovered, and the remaining ones don’t produce much honey, further reducing their resilience – and usefulness to humans
• Possible increase of mite virulence (I don’t understand why this is not an issue with other systems)
• The survival may be due to non genetic factors, like low hive density, or small cavities

Matthieu proposes that the way forward is a gradual (‘soft’) selection guided by human breeders, using negative selection to remove the most varroa-vulnerable queens. This should retain a broad selection of alleles.

Comment: I could be wrong, but it strikes me that every population of varroa tolerant bees came about through hard selection, without human intervention: AHB in Brazil; South Africa’s capensis and scutella populations; Russian Primorsky bees; our own local landrace, etc. I am not aware of any human-directed breeding programs that have developed a stable varroa resistance trait which works for multiple generations. Possibly the Swindon Honeybee project or Cuba? It will no doubt happen, but it seems to happen faster using natural selection.

Alex’s map of UK TF beekeepers

Alex Valentine is doing a PhD at Galway on the evolution of honeybees, and campaigning for a bill to stop non native bees being imported to Ireland. She presented her paper A survey of UK beekeepers’ varroa treatment habits done at the University of Salford under Professor Stephen Martin which I will summarise as “21% of UK beekeepers, i.e. 9% of the colonies, are treatment free”. At Galway she’s involved in the “Outside the Box” project searching for free living colonies outside hives. This has various aspects, which she summarised as mapping them; looking at local adaptation and morphologies; and analysing their genetics to see the impact of imports, using 60 reference samples dating back to 1880 in Dublin’s natural history museum. They’re also doing remote monitoring, and looking into the effect of cavity size. Wall / roof colonies seem to live longest, possibly because larger cavities have room to expand.

Filipe Salbany, based locally but with extensive experience in Portugal, America, and Africa, gave a talk on what has been found studying the wild tree colonies in Blenheim forest. A lot of us know him and I’ve discussed Blenheim elsewhere so here’s the new stuff:

• He’s noticing that nests appear to cluster in groups of 6-8. And these tend to be all in e.g. horizontal cavities or all in vertical ones.
• He reckons we’re going to have to move away from saying “these are pure Amm bees” to a finer grading of local ecotypes, each with very local adaptations.
• He currently knows of 76 nests at Blenheim, only 2 in dead trees. They favour beech and oak (but as the forest is mainly beech and oak I am not sure what significance to place on this – he suspects e.g. attractive antifungal resins).
• Established nests have an 82% winter survival rate. Late swarms only have about a 25% winter survival rate and can be distinguished externally, because they forage a lot more in late Autumn, trying to build up.
• He or his colleague Francis check every nest every 10-14 days.
• Only a handful of cavities are as large as a National. (This came up several times over the symposium, various people noting the sizes Tom Seeley recorded in the Arnot Forest seem very large for wild European nests.)
• Truly massive propolis entrance curtains. He uses the amount of internal propolisation to estimate the age of a nest.
• Not seeing robbing. These bees prioritise pollen.
• Mysteriously, wax moths don’t always chomp old deadouts. But WM are definitely present.

He sees Blenheim as a huge control experiment. He’s influenced the estate to move commercial hives off their land, and is beginning to influence neighbouring ones, and by next year there may be an area of 100,000 acres which are free of commercial hives.

Fanny Mondet (France) presented the findings of the Task Force’s Recapping study via videolink. You’ve perhaps heard of how bees uncap pupae, chuck out ones with problems (hygienic behaviour) and recap the cells. The Task Force finds that widespread varroa-tolerant populations of bees, from Africanised Honey Bees in Brazil to Apis mellifera in France, all seem to have a much higher capping/recapping rate than other bees. Using scalpels and other tools they’ve manually uncapped cells and found just doing this reduced varroa reproduction rate by about 30% (I confess the graphs were difficult to interpret). They are examining many factors like: is it more useful to uncap drones or workers; is there a balance of risks such as uncapping making colonies more susceptible to viruses…

This is another no-funding project, contributors get co-authorship. After several years’ work across 7 countries, the data is too poor to draw any firm conclusions yet because each country has followed slightly different protocols, it’s difficult to say if uncapping worked when beekeepers also treated with miticides! And there are a lot of confounding factors like many colonies in the study dying. There’s much better data from Asia (see next item).

One thing about the photos shown puzzled me. They showed the entire cap being removed, like a large circular shield being folded back on a hinge. I thought the bees sort of chewed a hole from the middle rather than sawed off the whole thing. Professor Stephen Martin explained they originally make a small hole, probably to check the smell of the pupa, and only remove the whole cap if they suspect a problem.

Sanchai Naree and Guntima Swuannapong (Thailand) gave another video presentation on the recapping behaviour of four bee species in Thailand: A. cerana, A. dorsata, A. mellifera and A. florea.

One aspect of this is, they manually uncap 300 cells (150 each side of a comb) and monitor its impact on both varroa and tropilaelaps. (Tropilaelaps is like varroa on steroids – not in Europe yet, but bee inspectors are very much aware of it.)

They find A dorsata and especially A mellifera recap up to 50% of cells whilst A cerana and A florea recap almost none – but they seem to have other ways of dealing with varroa so maybe don’t need this behaviour. Recapping is strongly correlated with fewer varroa.

I was impressed by the technical expertise involved. A florea are tiny, if stingless, and have a weird comb structure whilst A dorsata are as large as our hornets.

Melanie Parejo (Galicia, Spain – Universidad del Pais Vasco) did a video presentation on Surviving Populations of A.m. iberiensis in Spain.

Spain has 35,500 beekeepers managing 3,000,000 colonies (about 12x as many hives as the UK). Production fell 50% in 2022 from drought and increased production costs, and losses hit 40% in the Basque region. TF survivor bees would help immensely. Programa MENA involves 8 beekeepers running 150 colonies in an attempt to promote varroa resistance. Some have been untreated since 2015.

Hives are run foundationless, and warm way (to help cook varroa). An extra frame is put in each hive to reduce bee space (I don’t understand why). The regime is minimal intervention, but mite drops are monitored every 4 days and if the drop hits a threshold they are treated with miticides – and that hive is then removed from the program, because the beekeepers depend on the income, but they’re eventually requeened from survivor colonies.

The ECOAPI project compares management, hive type, environment, genome, microbiome, and social immunity behaviours like recapping – but all hives are A m iberiensis to reduce variables. It’s a new project, no results yet.

Complicating factors: several people pointed out that with some apiaries using 20 identical hives in a line, there would be a lot of drifting; and Filipe, who has experience not far away in Portugal, made the point that the woods will definitely have a wild population of survivor bees.

On a side note, I enjoyed the photos of traditional bear-proof apiaries. How did beekeepers stop bears before electric fences? With absolutely massive stone walls, with sturdy locked doors. These apiaries look like forts.

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General points

Most of day 2’s comments are worked into the writing above, but it’s worth mentioning that –

Raffaele explained EU strategy has shifted away from breeding one super-bee and is now very much focused on promoting the rearing of local queens adapted to an area.

Spencer and I aren’t keen on human selection. Vincent responded that most beekeepers are small scale and can’t affect much, which is why COLOSS concentrates on larger scale experiments. Arrigo added that COLOSS is about affecting populations, not individual hives or apiaries. And whereas Spencer and I aren’t concerned with honey crops, COLOSS have to consider what’s commercially practical.

Rosa Maria in France is concerned that the number of beekeepers is rising: hive density is rising as people get hives to “save the bees” and this can cause new problems, for example if they buy non local bees.

Discussions covered many bee species like AHB in Brazil, African bee genetics, Apis florea (it’s spreading rapidly through Africa), Thai bees, and isolated populations in Gottland, Cuba, Sahara.

Research often covers just a few dozen hives, so they are very excited about the large Blenheim conservation area with a significant population of TF survivor bees.

This is just one of many COLOSS Task Forces.

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Followup events

Vincent gave local beeks some tips on Warre management

Following the meeting, some of the COLOSS members visited a local non-treatment apiary for lunch. We examined the floor debris of a deadout to find a varroa mite, to show an Australian beekeeper who had joined us. It took a couple of minutes to find one (you will always have some, it’s not magic). Sandra from Mellifera eV in Germany asked how we do it. We explained we just use local swarms, don’t feed, and almost never open the hives – giving the bees the chance to use their inherent ectoparasite control behaviours. Whilst this hard Darwinian approach doesn’t work in Germany, where the original Amm is largely replaced by imports accustomed to regular miticide treatments, I think it gave her hope that they can encourage mite control behaviours and get there through a more gradual approach.

Jane’s traditional alveary survived a tough winter while wooden hives struggled.

Our Australian friend was very interested to see an alveary, as fixed comb (frameless) hives are illegal in Australia. We discussed hive design, warm way vs cold way, and Vincent explained to us amateurs some technicalities of bee space, drone flooding, and why prime swarms should stay in an area whilst casts can be distributed to spread desirable drones around buffer zones.

Steve stayed with me overnight, giving us the opportunity to view the wild colonies round my village 10km from Oxford. We looked at 8 wild colonies in roofs, walls and a tree, plus a couple of locations where colonies had died out. (Note Filipe’s earlier suspicion that nests cluster in groups of 6-8…) As Steve said, “and this is just one village!” There are something like 200 villages in Oxfordshire, though not all as full of crumbly old stone houses as this one. Oxfordshire is one of 48 English counties.

Steve is meant to be looking the other way at a bee tree, but got distracted by the forage opportunities of a ‘typical’ English garden

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Blenheim forest – beelining / forest craft training

800 year old Queen Oak, Blenheim Forest. Image by Jon Darvill

This was a full day event where Filipe Salbany trained 50 people in the grounds of Blenheim Palace. That’s more than the COLOSS meeting as some had come for the Learning from the Bees conference the next day.

The day initially covered how to behave in the forest to avoid damaging it – avoid stepping on roots, compressing soil near trees, walking outside the drip line of an individual tree’s canopy, what you could touch. People were split into smaller groups to visit sites in succession. 

Theory of beelining was taught, but it was quite cold on the day so bees weren’t flying much. However, nests of bees in ancient trees were pointed out and by the time people were deep in the forest, they were quite moved by the calm, wild wood and the giant trees towering over them. It was quite an emotional experience.

Filipe gave a demonstration of how to climb trees safely. It is vital to use the proper kit.

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My thanks to Steve and Arrigo for inviting us to these events, and to the researchers for being so open and welcoming. I hope I’ve reflected what happened accurately, and not distorted anyone’s views or research.