Back in the ’90s
In 1992, when Varroa mites were first discovered in Devon I attended a MAFF workshop to learn more about the mites from their scientists. Among other things they advised the use of tobacco smoke and sticky floor inserts to catch falling mites, therefore controlling its numbers.
By keeping their numbers under control it was thought Varroa may not cause colony loss. However, tobacco soon went out of favour and other means of control were sought.
Subsequently beekeepers in Britain followed the lead of American and European beekeepers in what was already happening and began using a variety of chemicals, some of which are still being used today, like Formic and Oxalic Acids. Both of which can be quite dangerous to humans, and not very kind to honeybees. The mite has become immune to at least one favoured chemical, Pyrethroid..
Some chemicals are now to be found resident in recycled beeswax after it has been heated, cleaned and processed for re-use in beekeeping. One can only wonder about the same recycled beeswax being used in cosmetics, creams and soaps, etc. for human use.
Also at that workshop the Varroa mite was described as “having a carapace like a crab” and “eight truncated legs like a crab“. At the time that description caused me to believe they were “hard and bony like a crab”. I was wrong. I later found out that adult Varroa are covered in hairs, soft, fleshy and very easily damaged.
This I discovered almost by mistake in 1994 when I decided to collect some Varroa mites to photograph at home with my Pentax 35mm slide camera attached to my microscope.
I inserted newspaper into the hive and allowed a few days for mites to fall onto it then removed and folded it. I stuffed it in my pocket and took it home. Upon inspection, not only were the mites covered with hive debris but they were also damaged. Certainly not worth wasting film on.
Though extra care was taken during later collecting I still found high numbers of damaged mites from one or two particular hives. It became obvious that the bees in these colonies appeared able to ‘deal’ with the mite and I needed to know how that was possible.
Following a couple of experiments I was able to prove the damage was being inflicted by worker bees biting the mites from each other. I was also able to determine this was a genetic function and not a learned activity.
I used one exceptional colony for the start of a breeding program which has developed over the last nineteen years.
Regular mite collecting and checking, using a 20/40 dissecting microscope, still takes place to enable improved selective breeding. Nowadays a very fine artist brush is used to gently collect and examine the mite in order not to inflict more damage. Collecting from a varroa tray which has been in place for about three days is easy as there will be only a small amount of other debris. The damaged carapace or missing legs are very obvious
The last two years have been made easier for me as two colleagues now share the evaluation task.
In the 1980’s I had been successful at instrumentally inseminating queen honeybees, nearly always accepted by their new colony. By 1995 my inseminated queens were no longer being accepted. The workers killed my queen and made one of their own. The only thing that had changed in my bee husbandry at the time was the arrival of Varroa and my use of chemicals.
Around the same time I had joined forces with a beekeeping friend. We had about eighty colonies between us. We could do little about Varroa but the chemicals were different. We made the decision to stop using them. This decision has since been upheld by scientific papers. From them came the knowledge that most chemicals being used at that time, and which are still being used, were the major cause of queen failure due to their adverse effect on the viability of drone semen. They also cause several other problems, one being the life-span of the bees.
If you “Google” The Effects of Miticides on the Reproductive Physiology of Honey Bee… you will find that Lisa Marie Burley, USA, has published her degree papers where she has drawn together many scientific papers which make interesting reading regarding the dangers and damage of Varroa control chemicals in everyday use by beekeepers worldwide. There are lots of pages so I suggest you start reading from page 6, 2.2 Miticide Use and The Effects on Honey Bees.
All our hives were relocated to a new site in 2004. They are now ALL fitted with Varroa floors; a wire mesh floor and deep removable under-tray to catch falling mites for later collection and assessment. Hives and trays are numbered for record purposes. Mites are carefully collected from the trays on a near-weekly basis making it easier to keep mites fairly free of hive debris and undamaged by us, placed into numbered mini-pots then examined under a dissecting microscope later.
A new discovery was made
By 2006 about 50,000 mites had been examined for signs of hygienic behaviour by the bees. Many thousands of them were found damaged, typically with carapace damage or legs removed. By 2014 around half a million mites had been checked.
In 2007 a new discovery was made. A colony was discovered where the worker bees seemed able to detect that Varroa were breeding upon the larval bees within capped cells. The cells were being opened and the bee pupae being removed and discarded from the hive.
My aged eyes are beginning to get the better of me so I now needed a strong lens to find the mites. I purchased a 7x loupe with LED’s.
During routine mite collecting I noticed that the Varroa tray of one hive had a central area completely clear of any hive debris. The mesh floor had an area above it where debris had collected and not fallen through. The floor was replaced for examination and cleaning. Using the new lens one of the first things I noticed were the almost transparent bee antennae (left). These had obviously come from immature bee larvae. I had not observed them before; the new lens made it possible now.
As these incomplete antennae are not to be found in other hives it suggested that the bees of this hive must be uncapping brood cells which contained Varroa mites and removing the larva and the mites.
The head of the pupae bee and its antennae are immediately behind the capping and would be the first parts to be tugged at by the workers. The woven wire screen floors allow some of these parts fall through onto the tray beneath The picture to the right shows a cell having been uncapped by worker bees. I have a video of this uncapping and larva removal happening to my bees.
Other colonies were found to be uncapping but not quite to the same degree.
When looking much closer among the floor debris i also found very tiny baby mites about I/6th the size of an adult. These fall from the bee larvae as they are being pulled from their cell.
The picture left shows lots of very young baby mites with an adult mite for comparison. A very high number of baby mites collected from that initial hive in 2007/8 proved that this hive was really getting the better of Varroa.
That colony was selected to play a major part in our future breeding programs.
Hygienic bee success
By now we had around 50 hives that have seen no form of Varroa control for many years, other than the grooming by the bees; no chemicals, shook swarm or drone culling . First the grooming and now the pupal bee removal causes a major set-back in the mite breeding cycle and dramatically reduces the potential build-up of the mite population.
The adult female varroa mite is capable of reproducing several generations; her daughters have the same potential. Therefore by the simple removal of baby mites and the grooming of adult mites, the bees have prevented a mite build-up of thousands. They are now independent and need no further help from me. My job now is to breed hygienic queens and distribute many more of them. My bees and varroa now co-exist.
To date lots of drones and queens were bred and distributed around Swindon. Some were retained for our studies. Queens heading colonies not showing a high degree of hygienic behaviour are culled and replaced with queens bred from some of our better stocks.
Another major discovery
“The 2015 season is going to see quite a few breeding and assessment programs undertaken which hopefully will improve our claim to having hygienic bees which will stop the loss of honey bees!””
I wrote that before last christmas anticipating the publication of information proving that my bees are exceptional. In case you haven’t read my NEWS page I have copied across the section below for you to read now (if you have read it please skip past it to read more).
Latest Headline News…. 26th October, 2015
Really Exciting News
My bees are IMMUNE to DWV
Hard to believe but very true
BBC South West have produced a film presented by Chris Packham showing the ground breaking work we’ve been doing over the past 20 years together with recent scientific findings.
is was available to view on BBC1 iPlayer for 25 days but has now timed-out. It is the second ten minutes of the Inside Out program dated 26/10/2015, click the following link to view the programme… BBC Inside Out South West
It is still available to view on youtube if you missed it, however, you must ‘Cut & Paste’ this link in your browser in order to view it until I discover how to ‘link’ it. https://www.youtube.com/watch?v=DUFDXl8VGvs
Scientists studied my bees starting in August 2012 and continued through 2013 testing monthly samples. They have written a paper relating their findings and the methods used, follow the links below...
and a brief explanation at www.mba.ac.uk/wp-content/uploads/2015/10/Mordecai-2015-Press-release-FINAL.pdf
(Phase 3) continued ..
The busy 2015 season was delayed by the late publication of the scientific paper, not by the BBC program. When the film was made in July 2014 the producer had agreed not to screen it until publication of the paper. — the paper was finally published on 27th October 2015.
That delay has set me back a year which I can ill afford as I will be 85 before the next season gets underway and must now set about breeding DWV Immune Queens and Bees; more or less with a blindfold on? Their immunity is a new virus which blocks the nasty DWV from affecting the bees. But how does one see a virus? How can I be sure the queens I breed have the immunity?
One other thing I haven’t yet mentioned. My varroa are also different to others in that they not only have the nasty version of DWV but also have an equal amount of the protector virus. How can that be?
With my team and the co-operation of an expert beekeeper in Salisbury we must conduct a variety of trials aimed at finding answers. Each test needs to be followed by having a virologist assess the results for us. this means I must now seek funding as such tests will be expensive, especially as a quick turnaround is needed with our short British queen rearing season.
Trials will be conducted using the bees of my Salisbury colleague as his bees are not immune. This will give us the opportunity to conduct a variety of projects.
1. Is it as simple as having a queen passing on immunity via her eggs?
2. Can my bees pass immunity on by feeding newly hatched Salisbury larvae?
3. Can immunity be passed on using semen from immune drones instrumentally inseminated into Salisbury queens?
4. Are my Varroa able to protect their hosts from their harmful form of DWV by passing on only their protector virus. After all, we are not yet sure how the immune virus developed.
5. Immunity may possibly be passed on simply by uniting a package of my workers with a similar number of Salisbury workers.
(These tests are only some of those we have in mind).
Now the virologist must do his assessments in order to determine how successful each trial has been. His fees are going to be expensive so I am seeking funding.
Can you chip in please?
Your donation should be made payable to “Swindon Honeybee Conservation Group” and sent to 10 Larksfield, Swindon, Wilts. SN3 5AD.
Some trials, even if deemed to be unsuccessful by the virologist will be replicated with some variant. Those deemed successful will be replicated often to establish consistency of results.
Watch this space as I will be noting progress.