We have heard of a number of unusually early losses of colonies this winter. There appeared to be no conclusive reasons for several of these. Over the years I have become aware of the attitude of many beekeepers who accept colony losses in winter as just ‘one of those things’. I remember seeing on television several years ago a beekeeper of apparent standing who was asked how many colonies he had lost during the recent winter. He replied rather casually “only four of my twenty”. The question came to my mind, as it always does, “But why did these colonies die out?” I know it can sometimes be very difficult to discover why we lose a colony, but I also think that it is important to try to find a reason rather than accept it as just ‘one of those things’. If our colonies are properly prepared for winter and as far as we can tell are in good shape in autumn, then why should they not appear in good condition in the spring?
May I remind you, especially new beekeepers, of those wise words of my beekeeping tutor: “The most likely time for a colony to die out is in the Spring when they are hopefully raising a lot of new brood causing rapid depletion of their stores.” So do keep a careful watch on you colonies’ stores from now onwards until there is some forage for them to bring in, especially if a warm spell is suddenly replaced by a very cold one.
Weybridge / Guildford joint meeting 21st February 2020:
Cobham Village Hall. 45 people in attendance.
The meeting was introduced by Andrew Halstead, Weybridge Chairperson, who reminded us that Varroa arrived in the UK in 1992.
There were two talks, one by Jonathan Brookhouse of Guildford division and the other by Marion Cooper of Weybridge.
“Searching for resilience in our honeybees” by Jonathan Brookhouse
Jonathan started by stating that he was aiming for resilience and not resistance to Varroa. Bees already have to cope with diseases, pests, climate change, environment change and modern beekeeping practices. Jonathan stated, ‘our bees need to be allowed to evolve together with the parasite.’
Why not treat bees for Varroa? There were various reasons posed, such as: residues in wax and honey, miticide damage to bees including queen longevity, drone development and disturbance to gut biome. His main concern is that the bees will become reliant on beekeeper intervention and that treatments will become ineffective when the mites become resistant to the treatments as has already occurred in many parts of the world.
Jonathan then looked at how bees are coping with Varroa. One study of 150 colonies on an isolated island that were untreated for Varroa between 1999-2005 resulted in only 13 surviving colonies. He looked at various studies on hygienic behaviour, which is measured by the efficiency with which bees remove dead brood from comb. More recent studies have placed Varroa mites under living capped brood to see if the bees will uncap and remove the larvae (and therefore the mites as well, interrupting the reproductive mite cycle). Ron Hoskins of Swindon Conservation Group has not used miticides since 1995. His bees apparently attack and remove Varroa mites.
They have also been shown to have Deformed Wing Virus (DWV) type B, which is not virulent and confers protection against virulent types A and C. Could this DWV variant be the answer to the problem of vector viruses?
Jonathan is also against importing bees as the European descendancy of bees from Africa takes a different route from that of the Eastern European and Middle Eastern bees. Debbie’s notes: (1) although speciation has not occurred so crossing should result in hybrid vigour. (2) All of this was very interesting, but I can see no way forward other than to stop treating your bees and cross your fingers!
‘Are there Varroa tolerant bees?’ by Marion Cooper
Marion gave an excellent recap of how Varroa was found across the UK in 1992, pointing out that Varroa became resistant to pyrethroid insecticides by 2006. Many Weybridge members suffered colony losses, although it was noted that there was not always a correlation between mite numbers and the state of the colony. There were various theories at the time about how some bees were surviving without treatment. Mostly this was championed by Ron Hoskins and his ‘bee to save all bees.’ However, if one of his queens was introduced to a distant colony there appeared to be no protective effect. It may be that isolation on Salisbury Plain was his saviour (as well as DWV type B).
In the late 1980s and 1990s Varroa was found to be a vector of viruses, the most pathogenic being DWV. Research on this is ongoing, much of it being continued by Prof Stephen Martin at Salford University and some others, and Marion suggested that we look out for the papers that he will no doubt continue to publish. Marion pointed out that without controlling Varroa we cannot control viruses. Colonies will survive for two to three years but will eventually collapse.
Most people attending treated their bees for Varroa. Marion advised to do mite counts, treat colonies if necessary and rotate treatments used to limit resistance developing.
Jonathan suggested that if the whole of Weybridge stopped treating their bees, then eventually we might get Varroa tolerant bees! Most people would find their losses high, however.
There appears to be no true ‘Varroa resilient bee’ as yet. However, organisms evolve and this is eventually possible but on a much longer time frame for the bees due to their slow generational turnover. How long? Who knows?
In the meantime I shall continue to treat my bees as necessary and keep abreast of current research and methods.
Special thanks to Chris Chisholm for her delicious cakes and to Anne and Jane for organising the refreshments.
Deborah Macey, Weybridge
Thank you, Debbie for this comprehrensive report, the first that you have provided for us. We look forward to many more.
Asian Hornet BBKA Conference Warwick, Saturday 8th February 2020
Click here and you will find a full report of the above important conference, which was attended by Jonathan Brookhouse, the Surrey BKA Coordinator, and Andrew Halstead, our Weybridge rep.
There is a huge amount of information in this, and some may not feel that they have the time to read it. However I think that as practical beekeepers we should take the trouble to read the section which is copied below for your convenience:
‘According to the literature and the experience in France, Asian Hornets will begin to emerge from winter hibernation when the temperature is consistently above 13°.
In the UK, this should be late in March to the beginning of April.
On the Island of Jersey, a single hornet has already been found in the beginning of January this year. It is thought to have been disturbed from hibernation. Last year, 2019, the first queen was found on the 6th February.
What beekeepers should do while they await the inevitable arrival of the Asian Hornet (my heading –Ed.)
It goes without saying that we need to be vigilant and really learn as much as we can about this dangerous insect. I am not listing here how to be vigilant, where to look or what to do for this month, we are all capable of finding this out for ourselves.
A good place to start is https://www.ahat.org.uk/and also https://www.gov.uk/government/news/asian- hornet-uk-sightings-in-2018
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