Bees Without Borders: conference report

Wild nest built in window in France. With the shutter closed it may well survive winter. The householder was delighted with their “observation hive”!

What: 6 lectures, mainly on wild / unmanaged bees, by European researchers titled Bees Without Borders – I attended by Zoom and the recordings have been released here. Some of the lectures were very technical.

When: 21st November 2020

Who: organised by the Swiss organisation FreeTheBees in partnership with the Natural Beekeeping Trust and Honey Bee Wild (Luxembourg). The lecturers were academics, a bee farmer and a couple of specialists.

What I learned: some key points were

• There is a lot of bleeding edge research going on in Europe we don’t hear much of in the Anglosphere.
• For many years, foresters have worked to minimise tree cavities, as they reduce the value of lumber. Now however people are beginning to deliberately create them for biodiversity, not just for bees (Zeidler beekeeping) but other creatures like bats and birds.
• No one has studied wild bees in Europe since at least 1800. They were just taken for granted, then it was assumed varroa killed them all. But combining data like “how many nests can we find in this area” and forestry information (tree types etc) across Europe, you can extrapolate that there are probably about 80,000 wild colonies in European forests.
• Importing foreign bees measurably weakens local strains.

The lectures were in French, but there was simultaneous translation into German and English. Most slides were in French.

DNA lineages across Europe

Fabrice Requier (evolutionary / genetics researcher at University Paris-Saclay) gave an interesting presentation on wild bee colonies- here’s a slide showing DNA lineages as little pie charts. The finding here is, broadly, that there is a lot of hybridisation in central European apiaries but lines in Spain, Britain and Scandinavia are purer. He referred to the recent Irish study which located 180+ such colonies. (That would be Professor McCormack’s one, she did a Zoom lecture for BIBBA recently discussing how the wild ones’ DNA was essentially pure Amm, presumably because Ireland is such a wet, challenging environment for bees, that any imported strains die unless carefully managed. Irish beekeepers are mad keen on Amm).

M Requier organised a similar study in France asking the public to report wild colonies, and found 250 wild colonies. Two thirds in [old] human structures, one third in trees and a handful in other locations like free hanging comb.

He was the first lecturer to mention feral colony numbers were impacted by hybridisation (weakening) with managed bees.

Unmanaged colonies. Bottom left is a hollow concrete electricity pylon with a 3 year old colony inside.

Vincent Albouy, entomologist and nature author, told us how he had tried keeping bees many years ago, but they died. Then a few years later he noticed his hives were full of healthy bees again, and he came across other wild colonies, which got him intensely interested in how unmanaged bees thrived better without our help. A literature search showed that wild colonies had been ignored in Europe since at least 1800: only Seeley (USA) and some Australians seemed to have done work in this field, so he launched a study to fill this data void, forming a group called The Bee Watchers who now monitor over 100 colonies, some of which they find using beelining and triangulation. Many are in old pollarded trees. One finding is that, unlike Seeley’s American forest bees, these French ones have a very high colony mortality rate so they now check them several times a year. They see a massive fluctuation in colony numbers from year to year but the population always bounces back from bad years.

The Varroa mite has 2 lineages, Japanese and Korean

Dr Yves Le Conte of IBRA gave an extremely technical lecture about how bees detect varroa, resistance mechanisms, mitochondrial DNA analysis of varroa lineages and Stuff… he began beekeeping aged 12 (50 years ago) and was aware of many feral colonies in chestnut trees in his area. Varroa wiped these out, but he noticed they returned a few years later, obviously able to cope with varroa now. He decided to stop treating his own colonies and only lost one thereafter.

By 1998 he was doing a serious project on resistant unmanaged colonies round Avignon, monitoring colonies where, for example, a beekeeper had died but their hives were fine. One colony lived 15 yrs!

French varroa mites are diverging into two subfamilies

Mitochondrial DNA analysis shows there are two varroa lineages outside Asia, the Korean and Japanese ones. These are both so inbred that they are referred to as clonal. In France, the Korean one is found. But new analysis techniques show this is diverging into two subfamilies – one is found in varroa resistant colonies, and the other in treated colonies! It’s too early to say for sure but the suspicion is that the subfamily in the resistant hives is evolving to be less virulent, because parasites that kill all their hosts die too. (This is one argument against propping up colonies with miticides: you actually evolve more virulent mites, by reversing the usual selection pressures. Mites in treated hives will only thrive if they breed incredibly rapidly.)

He also discussed:

• If you deliberately introduce ABPV or CBPV viruses into varroa-resistant colonies, they don’t get infected. More recent work (2017) with updated tools showed the same for DWV, SBV and other viruses. These survivor bees don’t just fight varroa, they survive all stresses.
• The “VPS” chemicals bees smell which reveal varroa are present, how scientists discovered these, how varroa-resistant colonies have more highly expressed olfactory genes and their antennae have been measured to respond more strongly to these chemicals. This seems common not just to French resistant colonies but the Baton Rouge strain in America, the Gottland strain and they are checking Africanised Honey Bees in Puerto Rico now.
• It is beginning to look like this recurrent similarity between different varroa resistant strains isn’t just in olfactory genes, but others like grooming behaviour etc. In other words, the bees are reactivating dormant behaviours they’ve had to use before and are common to many widely dispersed populations. But interestingly if you switch resistant colonies to a different country they lose their varroa resistance.
• Working with Professor Popova, a propolis expert, it was shown that varroa resistant bees collect a different blend of propolis resins – resistant bees’ propolis contains more caffeine! (Caffeic acid)
• Several IBRA teams are now using the latest DNA technology, SNP (Single Nucleotide Polymorphism) marker differences between VSH vs non VSH bees.
• His final point was that the French survivor bees are hybrids, 80% Amm genes – but well locally adapted. “Our great grandfathers’ Carnica is no longer necessarily the best bee given climate change etc.”

Vincent Canova has kept bees since 1972 at his family farm – up to 500 colonies (currently nearer 100). He teaches natural beekeeping and discussed, does commercial beekeeping need to be incompatible with natural bees?

His key points were that his original strong colonies of black bees were significantly weakened by hybridisation (yes, this sounds the opposite of Dr Le Conte’s final point, but it depends which bees you hybridise with) and the local bees made much more honey and needed less management than imported ones. I’ve heard this last point before from other people.

Comparing the productivity of local black bees with imports

His area – Ardéche – was dominated by chestnut trees and the local bees’ rhythms were in tune with these, but when varroa arrived and many colonies died he repopulated with bees he bought. He began losing colonies over winter for the first time. He had to feed them lots of syrup or they died. One slide (shown) compared an apiary of 17 Italian hives versus 18 locals: the Italians needed on average 5kg syrup to make 1kg of honey, the locals 1kg of syrup to make 4kg of honey. This seems like a compelling economic argument to use local bees if you have static hives.

In nearly 50 years of keeping bees, 1998 was the only time he bought any bees/queens/colonies. Of these 35 artificially made swarms, 29 of them died during the next winter.

Once he imported non local bees he began seeing nosema, the viral diseases DWV ABPV KBV BQCV CBPV LSV, and Paenibacillus lavae (American Foul Brood). (And ALPV – I don’t know what that is, I may have made an error in my notes.)

He formed a Black Bee conservation group with like minded concerned people seeing the same issues. They are working towards judicial recognition / protection of black bees.

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Verdict

4 or 5 stars out of 5. The lectures were information-dense and I had the impression I was missing some details as the translators struggled to keep up with the technical French – have just touched on some major points they brought out, here. The lectures have been published online in: English, German, and French – I would particularly recommend the last two to beekeepers interested in the reasons for keeping local bees. They’re about 50 minutes long each, there is a modest charge to recoup the costs of the conference (FreeTheBees is a charity).

I haven’t reviewed the first lecture by Prof Dr Hugo Bucher on biodiversity and extinctions over long timescales because I missed it.

 

 

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