“Varroa: still a danger; still a chemical solution?”
A talk by Richard Ball, 1st April 2021 via Zoom
What was it like 40 years ago? (before Varroa)
There was more ‘let alone’ beekeeping, but honey crops were still good, with clover playing an important role. 10% winter losses would be seen as high and there were virtually no medicament issues.
The first MAFF leaflet warning of possible Varroa infestation was issued in 1985, and the first confirmed sighting was in Torbay in 1992, but very few beekeepers were prepared for the arrival of the mite and knew what action to take.
When the mite arrived
With nothing to slow the mite population explosion, Parasitic mite syndrome became an all-too-common sight to Bee Inspectors. Symptoms include abandoned brood, dead emerging adult bees, damaged adult bees and visible mites on the bees and comb.
What is Varroa?
A mite, Varroa Jacobsoni, naturally infests the Eastern honeybee, Apis cerana. Man moved the Western honeybee, Apis mellifera, into Asia where Varroa started to infest mellifera colonies. It has since spread through Russia and Europe and most other parts of the world where A. mellifera is kept. Varroa found in A. mellifera in the west is thought to be a strain of V. Jacobsoni and is now called V. destructor.
The mite can only be described as ‘devastating’. It breeds in sealed brood, doubles population every three weeks in the active season and damages the immune system of the bees.
- A mature female enters a bee brood cell just before capping.
- She goes into the brood food.
- She emerges as the larva lays down to pupate and scratches a patch on the prepupa where her young will feed, then lays eggs in a specific order, male first.
- The eggs hatch out and feed on the pupa.
- Mature female mites emerge with the bee.
- They enter a ‘phoretic’ stage of about 4-11 days to mature and then enter a bee brood cell to carry on the reproductive cycle.
- Each female mite can reproduce 3-4 times on average and can stay in the phoretic stage for up to 6 months.
It is now known that the mites feed on the bees’ fat bodies, not the haemolymph as originally thought.
The first mite to hatch is a male. Subsequent mites are females which will mate with this male, or other males if two mites enter the same cell. Varroa mites prefer drone brood because the life cycle of the drone is 24 days, compared to 21 days for worker brood. Thus, a higher reproduction rate can be achieved in drone brood leading to more rapid attainment of critical infestation levels.
How are mites spread?
The answer is ‘Very easily!’ Human beings were largely responsible for the rapid dissemination of Varroa all over the British Isles. In addition, mites can spread by drifting bees, swarms, and collapsing colonies.
The problem with Varroa
By September, bee numbers are reduced, brood is reduced but Varroa numbers have increased, resulting in a high infestation rate of the new brood which will become winter bees. Infested bees are less likely to survive the winter. This is why a Varroa treatment in August, after the honey crop has been removed, is recommended.
Where do we go from here?
V. destructor is a parasite on A. mellifera at the moment but the relationship is subject to evolutionary pressures and could, in the future, evolve to a symbiotic relationship where the mite does not destroy the host. In addition, there are breeding programmes to develop ‘hygienic’ bees and/or Varroa tolerant bees. None of them have been wildly successful.
If we were to abandon all varroa controls, the survivors would develop as our feral bees have, using a number of techniques to enhance their survival. These may include more frequent swarming and uncapping of infected brood to kill mites. It is likely this would have commercial implications for crop pollination and food production.
Bee diseases act in concert
It is said that Varroa does not kill bees, though obviously it weakens them. Likewise, Nosema or Acarine do not kill colonies. Even viruses at low levels are unlikely to kill colonies. However, viruses transmitted by Varroa will exacerbate the damage caused by the mites and eventually weaken the colony so much that it dies. So, it is the combination of diseases that kills.
Many viruses have been identified in connection with honeybee colony losses. The list includes:
- Black queen cell virus (BQCV)
- Filamentous virus (FV)
- Bee virus Y (BVY)
- Bee virus X (BVX)
- Cloudy wing virus (CWV)
- Slow paralysis virus (SPV), Acute paralysis virus (APV)
- Deformed wing virus (DWV)
DWV has been identified as a significant killer to the extent that colonies with many deformed bees are considered to be in serious danger of collapse unless treated. However, although bees usually suppress the effect of viruses, the presence of Varroa appears to stop this in some way, so the virus multiplies rapidly resulting in sudden colony collapse. So, once viruses are well established in a colony, controlling the mites is less likely to stop colony collapse.
What does it take to kill a colony?
Three levels recognised:
- A few mites have little or no effect.
- Over 1000 mites can damage the colony.
- Over 3000 mites constitute a severe risk of colony damage.
This is the basic concept behind monitoring mite levels, so that as levels approach 1000 something can be done to reduce risk of damage.
Three principals have been put forward:
- The methods used should aim to control Varroa and disease levels, not eradicate them.
- Varroa and disease below the treatment threshold level should not be controlled.
- Chemical control methods should be the ‘last resort’, not the first.
These principals translate into Integrated Pest Management, as used by most beekeepers today. Using bio-techniques wherever possible and using chemical intervention only if necessary, allows colonies to develop in a more natural way. It should be noted that mite population counts can sometimes be misleading, so should be considered in conjunction with local conditions such as time of year and colony size.
Richard detailed many of the techniques that are available for controlling mite numbers. For more information go to BeeBase. His advice for improved chemical control was to pick those treatments that leave the least long-term residues. These include oxalic acid (found in rhubarb), lactic acid (found in cheese) and formic acid (used by ants). He also advised not to use the same product repeatedly.
Download the NBU Advisory leaflet: Managing Varroa (pdf 10.7 MB). This is a ‘Must Read’ for all new beekeepers.
To answer the original questions, ‘Yes’, Varroa is still a problem and ‘No’, the answer is not a chemical one. Richard suggests:
- Keep a local strain of bee.
- Select from the best surviving colonies.
- Monitor carefully.
- Only control varroosis when necessary.
- Use bio-techniques first.
- Use chemical control methods as a ‘last resort’.
- Use the ‘softer’ chemicals if you have to as the ‘harder’ chemicals leave more harmful residues.
This is the last of the Winter talks for this year, so our thanks also to Richard Simpson for all the arrangements and thanks to the small army of contributors, Zoomers and supporters. We hope you have enjoyed the talks and look forward to meeting you in person. Feedback welcome.
The talk may be viewed on YouTube HERE
You may also wish to download the BEEHAVE free software mentioned by Richard. BEEHAVE is a computer model to simulate the development of a honeybee colony and its nectar and pollen foraging behaviour in different landscapes.
* Image courtesy The Animal and Plant Health Agency (APHA), Crown Copyright
“Pollinator Landscaping, a Roadside Story?”
A talk by Leonardo Guber and Dan Field
Thursday 4th March 2021 via Zoom, with 31 participants.
Leo is Senior Ecologist with Highways England, based in Exeter. Dan recently retired from the same organisation specialising in land acquisition, highway law, and management training. Dan is a member of East Devon Beekeepers and it turns out that Leo has also kept bees in his youth and intends to take up the hobby again when he retires.
Roads and the Natural Environment
Leo stated that roads cut through virtually every terrestrial ecosystem in the world and have become a permanent part of the landscape. Understandably, roads have great ecological impact on the environment, often responsible for increased biodiversity loss around the world. Thus, road verges have attracted much attention as important areas of conservation and pollution mitigation.
The importance of road verges
Where main roads pass through farmed landscapes, the road verges may be the best quality habitat in the area, often with links to past landscapes, e.g. where old hedgerows border main roads. Verges tend to be relatively undisturbed and as will be shown later, verges can be of high aesthetic value.
The soft side of Highways England’s estate
The term ‘soft estate’ is used by road authorities to describe natural habitats adjacent to motorways and trunk roads. This amounts to 178,000ha in the UK, of which 30,000ha are in England, this region being managed by Highways England. The importance of road verges has gradually been going up on the agendas of both management and ecology since the 1960s, so what is the present-day situation?
Working with soft estate: what is out there?
To find out what is out there Leo uses a variety of techniques.
- Targeted surveys to inform environmental assessments and/or minimise the impact of planned operations.
- Desktop surveys to identify habitat boundaries of important sites and species recorded nearby.
- Drive-by surveys to identify areas that merit further investigation.
- Habitat and botanical surveys in areas of interest or that show potential.
- Soft estate conditions surveys.
- Ad hoc reports and inspections.
Constantly under attack!
The soft estate is constantly under attack. The list includes vehicle fires, litter, spillages, invasive species (ragwort, winter heliotrope, Japanese knot weed), plus a constant barrage of pollutants (zinc from tyres, cadmium from oil, salt from de-icing and nitrates from exhausts).
The Importance of road verges
The importance of road verges can be seen in a 2014 study by Plymouth University. Their surveys showed that bumblebee abundance in verges was more than twice that of field margins. Also, that species richness and abundance of flowers used by bumblebees was higher on roadside verges.
The Study statistics:
- Carried out in 42 different locations in Devon and Cornwall.
- In total, 866 taxa were recorded.
- These included: 32 different species of bees, 16 nationally scarce species, 4 species of principal importance and 1 endangered species.
Biodiversity Conservation Initiatives
The department have a simple method of species rich grassland creation. It uses the ‘whole crop’ or ‘green hay’ method whereby seed material from existing species-rich roadside verges are harvested and introduced at cleared, prepared sites where scrub and self-seeded trees had taken over the verges. The ‘before’ and ‘after’ pictures show the effectiveness of this method and comments in the press!
A30 and Goss Moor Marsh Fritillary Project
This is a Highways England led project, in partnership with Natural England and Eden Project, aimed at creating biodiverse habitat along the A30 in Cornwall.
The Moor is one of the main breeding sites in England for the rare Marsh Fritillary butterfly. The long-term survival of the Marsh Fritillary is dependent on maintaining a suitable habitat. The best sites are open, unimproved, lightly-grazed grasslands with abundant patches of Devil’s-bit Scabious, the caterpillar’s only foodplant. Eden Project raised 10,000 plugs of Devil’s-bit Scabious which were successfully planted on Goss Moor.
HERE is the link to view the talk on YouTube.
Black Bees – ‘The Past or the Future?’
A talk by Jo Widdicombe on 7th January 2021, via Zoom
Also participating were West Dorset Beekeepers group and Somerset BKA
Alastair Bruce, Chair of East Devon Beekeepers, introduced Jo, who is the President of the Bee Improvement and Bee Breeders Association (BIBBA). The aims of BIBBA are
‘the conservation, restoration, study, selection and improvement of native (Apis mellifera mellifera) and near-native honey bees of the British Isles’
What are Black Bees?
Jo first of all showed some images of Black Bees, workers and queen, which clearly showed the characteristics that set them apart from the mongrel bees that exist in most of the British Isles. These features can be seen in the screen shots from the talk.
The hairs on the thorax tend to have a yellow/brown tinge
The queens are dark
If mated with drones of the same race then all the bees in a colony look similar
The workers have only narrow lighter bands on the abdomen
Black bees are the native sub-species of honey bees, sometimes called the Dark European Honey Bee, and famously declared extinct by Br. Adam. Prior to about 1850 the Dark European Honey Bee predominated in France, UK, large areas of central Europe and extending northwards as far as Sweden. Since then, imported bees with distinctly different characteristics have flooded into the British Isles to produce the mélange of characteristics we have today.
The genetic makeup of our bees
The genetic makeup of our bees was studied by Dr. Elleanor Burgess and Dr. Catherine Thompson who found that about 45% of UK bees had mellifera genes, the rest being a hotch potch of genes from all round the world.
Breeding in this very mixed population often produces problems of ‘defensiveness’ and ‘uselessness’, so where do we go from here? Do we try to put the clocks back to 1850, or find the best way to move forward?
Finding a way forward
Imported bees are the root of the problem and they also pose a high biosecurity risk (Isle of Wight disease, Varroa, SHB, viruses, to name a few). Although crossing sub-species has the advantage of hybrid vigour the resulting subsequent uncontrolled matings will not breed true and are likely to cause ‘defensiveness’ and other unwanted traits. Also, the imported bees are brought in from other climates with no local adaptation and prevent us developing the best bee for local conditions.
The National Bee Improvement Programme (NatBIP), a BIBBA Initiative
NatBIP came about because of concerns about declining bee populations after Varroa was discovered in 1992. DEFRA’s ‘Healthy Bees Plan’ of 2009 aimed to achieve a
‘sustainable and healthy population of honey bees for pollination and honey production in England and Wales…’
The Plan identified imports as a biosecurity risk to our bees. Unfortunately, since 2009, imports have more than trebled!
Queen Rearing Working Groups (QRWG) were set up to identify the reasons for the popularity of imported queens. These reasons turned out to be ready availability, generally cheaper, good quality. Given the perceived advantages of imported queens
‘a good reason is needed for beekeepers to favour home-reared queens’
NatBIP is an attempt to refine our honey bee population with the aim of:
- Reducing imports
- Improving the quality of our bees
- It is a proposal for a sustainable programme of bee improvement
- BIBBA is not proposing a ban on imports, but is aiming to provide an alternative to imports, and a reason for not using imports.
Can sustainable improvements be achieved?
The aims can be easily stated:
- A self-supporting and sustainable system, able to maintain and improve quality over successive generations.
- Maintain genetic diversity but within a useful framework.
- Encourages ‘local adaptation’ producing bees suited to, and thriving in, its local environment.
- Aims to produce a hardy, docile and productive bee.
- Produces a bee that adapts and evolves over time to changing conditions – a bee for the future, not the past.
How can we implement a system that fulfils all these points?
Beekeepers and bees must both benefit for a sustainable system to emerge. The major prerequisite is participants should avoid the use of imported stock, or offspring of recently imported stock. The Programme is based on the best available local bees, built on ‘natural’ and ‘artificial’ selection. Nature selects for survival. Beekeepers select for the qualities they want.
Outline of how the Programme will work
Participants will keep a record of their colonies’ performance (this is not a management record). This will allow the selection of ‘breeder queen’ to produce the next generation.
Image of record card
The key to the system is the ‘breeder queens’ because the daughters reared from good breeder queens produce good drones, so selected breeding or mating zones can be flooded with these superior drones to develop a local strain.
Diagram of cycle of drone management
The advantages of breeding from ‘what we’ve got’ are a reduction in biodiversity risk, avoiding the introduction of new and untested genes. There will also be a gradual reduction in hybridisation as the ‘natural’ and ‘artificial’ selection shapes the population. As bees start to breed true the result is more rapid progress. Open mating helps maintain genetic diversity so the end result will be locally adapted bees with enough genetic diversity to select any qualities we want.
Summary of NatBIP
All beekeepers can benefit from a sustainable programme of bee improvement thereby reducing biosecurity risk. The programme will be based on current stocks and use a combination of ‘natural’ and ‘artificial’ selection to develop better quality bees. The Improvement Programme will not use imported bees or the offspring of recently imported bees.
BIBBA will produce a Guide Book with suggestions and ideas for beekeepers to choose and adapt to suit themselves.
To join BIBBA go to their Website and follow the links.
Useful reference: The Principles of Bee Improvement by Jo Widdicombe
An online poll was carried out during the meeting. See results sheet below.
During the Q&A session Jo gave details of the mating nucs he uses. They are made by Abelo and are big enough to overwinter small colonies. Abelo UK website
Our thanks to Jo for this information-packed talk and for permission to use the images. Our thanks also to Lynne Ingram for organising the Zoom meeting.
“From Start up to Kilnasaggart”
A talk by Thomas O’Hagan of O’Hagan Meadery, and member of East Devon Beekeepers, 3/12/2020
Thomas was introduced by Richard Simpson as one of the participants on the Beginners Course several years ago. As a scientist he was interested in fermentation processes and so realised he could turn his skills in fermentation and his hobby of honey production into a commercial enterprise making mead. So how does he do it?
Yeast and Honey
Put simply, mead is fermented honey. The honey provides the sugars and yeast supplies fermentation in a watery mix. The products of fermentation are alcohols and carbon dioxide gas, provided there is insufficient oxygen from the air to spoil fermentation, hence the air lock used in home brewing.
The carbon dioxide is the same gas that causes bread to rise and the fizziness of champagne, so mead can be still (all sugars have been fermented) or fizzy (some gas retained).
The type of yeast used affects the end product markedly. Standardised, dry powder yeasts are often used but, for the more adventurous, a host of botanical materials can be added to the brew to achieve subtle flavours. Wild yeast fermentations, such as these, can go disastrously wrong but honey is considered a very forgiving medium because potential spoilage microorganisms will be discouraged by the natural antimicrobial agents in honey.
Meads and Mythology
The fermented product called ‘t’ej’ in Ethiopia has a long history and is still consumed to this day. T’ej is a honey wine made with gesho, which consists of the leaves and stems of an Ethiopian thorn bush, the bitterness of which counters some of the sweetness of the honey.
In Greek mythology Ganymede was cupbearer to Zeus, having been abducted by an eagle, and representations of the event can be seen is Roman mosaics, as at Bignor Roman villa in Sussex.
There is a story of St Brigit of Ireland who performed miracles, including the occasion when she blessed the empty drinking vessels of the host ‘and they were at once full with choice mead’.
Kilnasaggart pillar stone stands in a field not far from Kilnasaggart Bridge near Jonesborough, County Armagh. Thomas’ father also makes mead not far from here, hence the Irish connection.
Make Your Own Mead
Many styles of mead have been tried over the centuries. Braggot is a form of mead made with both honey and barley malt. Heat or freeze distillation will produce a more potent brew from normal meads. Meads made with foraged flavours and fruits can produce very acceptable products and, of course, there are a whole range of mulled and spiced products (metheglin, melomel, cyser) that can be produced with additional ingredients.
The process will be familiar to home brewer:
- Add the fermentable ingredients (honey, other sources of sugar) to your Primary fermentation vessel
- Add yeast if required
- Add water and nutrients (such as Young’s yeast nutrient).
To make, say, a 12%abv mead there are calculators on the internet that will help you get the proportions right.
All that remains is to age, bottle and drink!
Thomas gave us a simple, fool proof recipe for beginners.
- Add ingredients to fermentation vessel (could use a clean honey bucket):
- Honey – 500-600g
- Water – (use calculator)
- Nutrients – (if required)
- Rack and continue with 2nd fermentation.
- Settle, bottle/age, drink
Selling your Mead
Thomas briefly took us through the necessary requirements for making and selling Mead.
- You will need Environmental Health Dept. approval of your HACCP procedures (Hazzard Analysis Critical Control Points).
- Trading Standards need to be involved.
- The Tax Regulations will require you to register as a wine producer, and pay duty on the alcohol content.
- You will need to join the Alcohol Wholesaler Registration Scheme.
- You will require a business bank account and the backing of a retailer. VAT will be required, plus a Premises licence.
- If that was not enough you will require Insurance and you will have to comply with the current Labelling Regulations.
Good luck with your brewing.
Brewing equipment supplier – Vigo of Dunkeswell
Thanks to Thomas for all the practical hints and tips, and also thanks to Nick Silver for stepping in at the last minute as host.
Report of East Devon Beekeepers AGM 2020 & ‘What I did During Lockdown’
Held via Zoom, 5th November 2020. 36 attendees.
Our President Hilary Kirkcaldie, opened the meeting with a warm welcome to everyone. As part of the address, she reminded us of past members who had sadly passed away this year. Hilary spoke of members who we may not have all known, but who were keen and committed beekeepers in their time. Hilary led us in quiet reflection in tribute to Evelyn Pelham, David Lench and Verbena Evans.
Our AGM is a chance for members to hear what has been going on in the group over the last year and for them to vote-in Officers and Committee members. The meeting was conducted efficiently as much of the information had been issued beforehand. The new Committee are:
|Committee||John Badley, Mary Boulton, Sarah Collins, Ralph Cox, Nicky Langley, Rosemary Maggs, Colin Osborne, Ann Pengelly, Richard Simpson, Peter Weller|
|Branch delegate to DBKA Executive Committee||Peter Weller|
Val Bone will also be Membership Secretary, Richard Simpson will be Education Officer and Keith Bone will be Apiary Liaison Officer.
Honiton Show Committee members will be Keith Bone, Ralph Cox, Angela Findlay, Sue Johnston, Mike Walters and Sarah Collins.
There followed two short talks by Jan Morse and Alasdair Bruce entitled ‘What I did during Lockdown’.
Jan started by telling us that for some years she had been leading two groups of walkers and along the way had been trying to educate them into the diversity of wild flowers in the vicinity of South Chard.
So when the first lockdown started she emailed her friends and said she would send them a photo each day of flowers they could look out for as they went on their walks own walks. From the beginning of lockdown to the end of Augest she sent a total of 188 different plants that she had seen in the hedgerows.
Jan then shared with us about twenty of the more interesting specimens with comments on their botanical properties. See the selection below.
Beautiful St John’s wort
Early purple orchid
Meanwhile Alasdair has been busy renovating a collection of hives that had been given to him by a farmer friend. They were obviously of an early design and had been kept in a barn for many years. There were even the remains of foundation in some of the frames!
Intrigued by the design, Alasdair started to search for their possible origins. The hives were well made which indicated commercial manufacture, and after a few enquiries he came across a reference in an old book from 1930 entitled ‘Bee-Keeping new and old described with pen and camera by W. Herrod-Hempsall. F.E.S.’
Burgess telescopic hive
So they are provisionally identified from an image in the book as Burgess telescopic hives from around 1930, this age based on when the tin spacers on the comb frames stopped being made as around 1930.
Thanks to all concerned for their contributions to the success of the meeting. Let us hope that next year the situation will have improved.