As an experienced beekeeper and representative for the LBKA this is a question that I have frequently been asked for advice on over the years. It’s a question with no clear cut or easy answer but one which I have a burning desire to find answers to and hope to explore in a future PhD project.
Beekeeping at height has increased significantly over the past decade as more and more city dwellers opt to keep bees on their roof tops and terraces. Keeping bees on roof tops in built up environments where space at ground level is in short supply makes sense as it utilises dead space. There are also added security benefits of siting hives off the ground and out of reach of thieves and vandals.
At the height (excuse the pun) of this craze are the increasing number of corporates opting to keep bees on their premises under the misguided notion that doing so in some way helps saves the bees which they perceive to be under threat and is good for the city environment and biodiversity. It is widely believed that being seen to help honey bees demonstrates good social and environmental responsibility and boosts a company’s green credentials.
Firstly, we need to establish that Honey Bees in the UK, Europe or indeed on a global level are in no immediate danger of going extinct. Despite what the sloppy journalists working for the tabloid press would have you believe there is no impending honey bee apocalypse on the horizon.
In the UK honey bee numbers have recovered from declines beginning in the post War 50’s and now stand at around 250,000 managed colonies (excluding N Ireland) with amateur beekeepers up from 8,500 a decade ago to 25,500 in 2015 (source: DEFRA and BBKA 2016). Across Europe colony numbers are up by an estimated 7% in the 5 years from 2005 to 2010 (Breeze et all 2014) and in other parts of the world significant increases in colony numbers have been witnessed.
In North America the US Department for Agriculture announced in 2015 that national colony stocks were at a 20 year high, exceeding numbers of hives before the first instances of Colony Collapse Disorder were reported (USDA 2015). China has seen increases of its numbers of managed hives as fruit producer’s battle to overcome the expensive need to hand pollinate Nashi Pears and other orchard fruits. New Zealand has significantly increased its national stocks of Honey bees in response to the unprecedented demand for Manuka Honey – a product which 20 years ago beekeepers in New Zealand struggled to give away until it was discovered to have miraculous medicinal benefits. When we separate honey bees from other bees (which are under serious threat) it’s clear that they are not in immediate danger and that managed honey bee stocks are again at healthy levels. Concerns about fulfilling pollination demands stems from our own human population’s ever growing need to grow more food.So corporates wanting to place hives on their roof tops to help bees is not really needed as honey bees are actually faring well. Their solitary cousins however are not so lucky.
Many cities now house substantial numbers of honey bee hives. NYC reportedly has around 450 hives, Washington DC around 200 and Metro Atlanta almost 5000! (pers comm with American BKA’s 2015). Many European cities accommodate healthy numbers of managed hives.
In London stocks of honey bees stood at 4218 colonies as of December 18th 2014. In 2015 this rose to almost 5000 registered colonies, many of which are to be found in the city centre parts of which contain an average of 13.5 hives per km2 (National Bee Unit 2016). With all these honey bees in a very built up environment already short on flowers, pumping more and more colonies into the city does not make sense and in no way benefits biodiversity or helps the environment. There are already sufficient honey bees to pollinate the cities trees and adding more can stretch floral resources thinner.
There is also the question of how increased numbers of honey bees places wild pollinators under greater pressure through resource competition. Wild bees have physical and behavioural adaptations which allow them to avoid competition with other bee species including honey bees but when resources are in short supply competition may be forced upon them. There is also the possibility that high densities and movements of honey bees could pose a disease risk to wild bees. Nosema, Deformed Wing Virus and parasites associated with honey bees are now frequently found in other species (Goulson & Hughes 2015).
Companies could be doing more for the environment and biodiversity by supporting planting initiatives and helping wild bees through the installation of solitary bee nesting habitats. In doing so they would be earning real green kudos.
So now we’ve established that opting to keep honey bees isn’t the huge boost to one’s green credentials corporates often assume it would be – that doesn’t stop some of the semi commercial beekeepers from telling them it is so when cash is involved. Herein lies another conflict.
‘cash for bees’ brigade
Most beekeepers have their bee’s welfare at heart and want to see their bees thrive and do well, not least because they will get a better honey crop from them and if you’re a commercial keeper then this honey represents an income. In towns and cities however a growing number of beekeepers now make more of their income from running training events and from offering managed hive solutions to corporates. They’ve been branded with the term ‘cash for bees’ beekeepers.
The problem with accepting money to maintain hives for extremely wealthy corporate clients who think nothing of blowing a few grand on improving their corporate image and impressing their wealthy clients is when money comes into play ethics and common sense often go out the window.
Beekeepers aware that the bees won’t do terribly well and make as much honey as they could do if kept at more sensible locations may turn a blind eye to the obvious as the honey is not theirs and they are usually being paid a far more lucrative income just for tending the hives, than if they were keeping bees for honey production. Conflicts of interest soon creep in.
Sums of £2-3000 per year per hive are not uncommon, some cash for bees keepers are charging £500 just for a risk assessment – something which usually takes very little time and effort for an experienced person. Some ‘cash for bees’ beekeepers also claim to have cracked the bees to flowers ratio and offer a flimsy pseudo-scientific analysis of potential locations to justify positioning bees in less than desirable sites. Many also claim to be sustainability experts when there academic background and real professions lie elsewhere. Take the time to ask what field of research their PhD studies were in. Chances are it was in something like theatre and not ecology or biological life sciences.
Often those offering ‘cash for bees’ services also emphasis the fact that they are part of a beekeeping association or perhaps even an association official. Beekeeping associations seldom endorse individuals or provide references to potential corporate clients. Furthermore official representatives of associations are bound by their constitutions to declare conflicts of interest and not to abuse their positions for financial gain. Membership of a BKA also does not carry any weight in terms of the person’s skill and competence as a beekeeper. The RSPB has over 1 million members but that doesn’t make them all expert ornithologist does it? Ask to see a keepers bee basic, honey bee management or general husbandry certificates which are British Beekeeping Association issued qualifications in cognition of one’s ability as a beekeeper. You can read more about beekeeping qualifications here: http://www.bbka.org.uk/learn/examinations__assessments
The problem is most corporate and social responsibility managers for these corporations know very little about bees and are very gullible. If a ‘cash for bees’ keeper turns up in a bee suit acting like an expert on the subject and tells them honey bees are in decline, in trouble and they will be helping them, the CSR manager is likely to believe them even when it isn’t true and front cash for bees.
Seeking Green Kudos the easy route can backfire spectacularly!
In the last few years numbers of corporates in the city acquiring bees has increased significantly. A group called ‘In Midtown’ once boasted the ambition to house the largest number of urban roof top hives in London which encouraged many neighbouring businesses to invest in bee hives. Many prestige hotels have also acquired bee hives so that they can sell their honey for ridiculous prices in their gift shop or charge a bomb for it in a dish served in their fancy restaurants. The problem is there is always a wealth of filthy rich customers willing to pay for the experience and this drives demand for bees on hotel roof tops. For example in New York the Waldorf Astoria has 6 hives 20 storeys above street level in view of the Empire State building for which they charge guests $1800 to witness a hive inspection lasting up to an hour followed by honey themed treats in the restaurant. Experienced keepers in Manhattan advise against siting bees higher than 6-8 storeys as the wind speed and turbulence makes it difficult for the bees to fly and not profitable from a honey production point, yet many keep bees for corporates at dizzy heights because cash is involved. The same is true in cities across the western world.
There is a real danger however of these prestige establishments lust for green kudos back firing on themselves as has been witnessed in 2015 when a well known prestige hotel in London had to have its 2 hives destroyed after recommendation by government bee inspectors following neglect to manage the bees properly and the outbreak of disease.
Many establishments have reluctantly been forced to give up their bees, donating hives away to BKA’s after swarms caste from their hives upset their neighbours. In 2012 two hives had to be relocated from Covent Garden, central London after the bees repeatedly stung bathers at a neighbouring leisure centre with an outside pool.
In 2011 bees from roof top hives at Oxford Circus shut down the cross road junction for hours when they alighted on road traffic lights meaning the bus drivers could not read the signal lights. Mayhem ensued. It took 3 beekeepers many hours to clear up the bees.
Keeping bees in the city centre is a lot of fun and rewarding until they fly into a neighbouring restaurant, scare away their customers and cost the establishment a days’ worth of revenue! This actually happened for real in the summer of 2013 in London’s Piccadilly Circus when 3 times in 10 days a hive on the roof of a commercial property swarmed. Each time the bees descended onto people at ground level costing 1 restaurant a whole days’ worth of takings, a local green grocer £4000 in lost earnings, caused a traffic obstruction and stung several members of the public and police officers attempting to cordon off the area. On each occasion volunteer swarm collectors from the London beekeeping association had to leave their days jobs to attend the scene as the beekeeper being paid to tend to the hives was conveniently not available having a full time job of his own. This is one of my real bug bears about ‘cash for bees’ keepers, they take your money to install and manage hives but are seldom around to deal with the chaos of a high profile swarm in the city centre.In summer 2015 a Netherlands based commercial services company with bees 14 storeys up on a sky scrapper in London’s Canary wharf were the talk of many neighbours after a swarm appeared 200ft above ground level on the adjacent high rise building. Office workers were panicked when they discovered the swarm clinging to their windows and were fearful they may enter the building. Volunteer swarm collectors had to be winched up the side of a building in a safety harness to retrieve the swarm to the amazement of onlookers. The people responsible for managing the Canary Wharf hives claim the swarm did not come from their hives but at 200ft above ground level on the opposite building where else would they have come from?
How high do bees nest naturally?
Legendary honey bee biologist Thomas Seeley who studied honey bees for many decades discovered that Honey bee swarms have a preference for nesting between 3-6 meters off the ground, though they will occasionally nest higher than this as well as occasionally nesting lower down, even at ground level. Honey bees probably prefer to nest several meters above ground because the height affords them a degree of protection from ground based mammalian predators such as badgers and bears. Natural cavities of sufficient size are also more likely to be found in mature trees at these heights. In urban areas we often find feral colonies of honey bees in buildings higher than this, often in air bricks. Bees are adaptable and in man-made environments will nest at higher heights than would normally be found but in the many call outs to remove bees from building cavities I’ve never came across a feral colony any higher than 3 storeys high.
It is not known what the maximum altitude is for honey bees to fly at though they are rarely observed flying higher than 30 meters or 100 feet above ground level. This is most likely due to the fact that bees prefer to avoid strong winds and the higher we go the faster the wind speeds become.
Honey bees are very much a fair weather insect and are reluctant to fly in wind speeds above 15 miles per hour (Morse and Hooper 1985) or force 4 on the Beaufort wind force scale. This is described as a moderate breeze rustling leaves and vegetation, or sufficient to fill the sails on a ship. When this increases to a strong breeze of 21 miles per hour (force 5, Small trees sway, leaves and small branches blow around in gusts) bees really begin to struggle to maintain controlled flight. Flying in stronger winds requires the bees to spend more energy maintaining controlled flight and they will tire more quickly and reach point of fatigue.
Increased wind speed also increases the wind chill, making actual temperatures appear significantly colder, the bees can lose heat and energy more quickly and if they become chilled and inactive they may die. Maintaining metabolic activity outside of the hive in cool conditions again causes the bees to burn more calories and expend more energy. Honey bees seldom fly when temperatures are below 12 degrees Celsius and then they won’t travel very far.
Other repercussions of flying in strong winds include increased instances of drifting with bees alighting at the wrong hive, resulting in fighting at the hive entrance and increased risk of pathogens being spread between colonies. This is one reason why high rise beekeepers in NYC experience poor rates of successful queen mating.
It is well documented that wind speeds increase with height this is termed ‘wind speed gradient.’ For example a ground level wind speed of 21mph (a strong breeze on the Beaufort wind force scale) can increase to 27mph (a strong wind capable of inverting umbrellas) 100 metres above ground level (Bañuelos-Ruedas et al . 2014) . Even on calm days when there is very little to no apparent wind speed at ground level wind speeds 20 metres above ground level could reach 13mph. There are numerous mathematical models for illustrating how wind speed gradients increase with height but the actual wind speeds experienced depends very much on the location and local topography. Physical objects in the landscape including buildings, trees and presence of open water all influence wind speed gradient. In towns and cities rows of tall buildings can channel winds. When strong winds collide with tall buildings strong downward drafts can result, this can make it difficult for bees flying against them trying to return to their high rise hive with heavy loads they have foraged. River valleys are also notoriously windier because the open water of the river offers no resistance to the winds resulting in faster wind speeds and sharper increase in wind speed gradient along river corridors.
The wind speed gradient can have a major impact on hives kept at heights above a couple of storeys reducing the amount of time the bees can experience good flying conditions.
The London Honey company keeps bees on the rooftop of the Tate Modern Gallery on London’s South Bank. They relocate the Tate hives from their modest 5 storey perch each winter to ground level, citing the extreme winds billowing down the Thames valley too troublesome for the overwintering bees. This is a thoughtful act and an example of a company putting the welfare of their bee’s first. Most corporates with hives on tall buildings have nowhere to relocate their hives to ground level in winter when conditions are at their harshest for the bees.
Honey bees prefer natural nest sites with an entrance facing the equator (Seeley 2010). This is because exposure to morning sun aids the honey bees in warming their flight muscles in preparation for leaving the hive and going out to forage. Facing managed hives south or south east benefits the same way as well as preventing prevailing westerly winds from blowing in through the hive entrance. Where possible high rise hives should always be positioned facing south or south east. On roof tops where bees are exposed to increased wind speeds and increased wind chill it is vital that this rule be followed to provide maximum benefit to the colony and protection from the elements. It is also worth checking which direction the prevailing wind comes from (it may not be a direct wind, tall buildings can deflect winds) and siting hives so that they are protected by a wall, chimney or other obstacle to break the wind. Checking the wind speed can be done easily with an inexpensive anemometer which are readily available to buy.
What research has been done on keeping bees at height?
Precious little scientific research has been carried out looking at the effects of keeping bees at great height on tall buildings. In the USA where bees have been kept on tall buildings in many cities for a number of years, there comes a great deal of conflicting anecdotal evidence from different keepers.
In the far north (similar latitudes to London) keepers frequently state that bees don’t do too well above 10-15 storeys, less so in cities on the Atlantic coast or cities located in a river valley or where several river valleys converge such as New York City. Cities away from river valleys and the coast seem to be able to keep bees higher more successfully.
In the Southern States I have met 2 beekeepers who both successfully keep bees in Atlanta Georgia 30 storeys above ground level. The significant difference here is the climate which is significantly hotter and being far inland less influenced by coastal winds.
In NYC for a number of years a small group of beekeepers
have been monitoring hives on tall buildings equipped with an assortment of
remote sensors including hives scales to monitor how the colony gains weight, a
bee counter at the hive entrance which collects data on numbers of foragers
leaving and returning to the hive and temperature sensors. Anemometers have
also been used to record wind speeds at different locations. Thus far only a
small number of hives have been used in this low key study so the results are
not statistically significant but their data gathered does suggest that at
higher heights where wind speed is greater, colonies are less productive, gain
less weight, more foragers leave the hive than return and they have reduced
mating success with their queens.
The researchers believe that colonies higher up experience increased loss of young bees on their first orientation flights. Basically the young bees are weak flyers and are being swept away by the high winds and are unable to find their way home. Increased mortality among young bees orientating then leads to a reduced recruitment to the colonies foraging force. It is also hypothesised that bees at greater heights may live shorter lives as a result of their increased efforts flying in less than favourable conditions. Most of the beekeepers I’ve met in Manhattan have to buy in replacement queens each summer as they struggle to raise their own queens and have them successfully mated in the city. High winds will make it difficult for queens to fly and there is also talk of whether or not the winds and tall buildings are making it difficult for drones to successfully form congregation areas where mating occurs.
These initial findings provide some indication as to the hardships we may be forcing upon our bees by citing them at unnatural heights.
So how high is too high for London?
When we examine the above information and look at London as a city, we can compare it similar cities in the US such as New York or Toronto. Our climate is similar but we have a wetter climate than either of those cities due to the effects of the jet stream which brings moist turbulent weather fronts our way from the Atlantic. London like NYC is in a river valley and along the river in particular wind speeds are greater as they are channelled down the valley. Following the helicopter crash in Vauxhall several years ago there has been increased concern over how the construction of the many proposed new sky scrapers along London’s river corridor will effect wind turbulence to low flying aircraft. These new buildings could also create more turbulent conditions for our bees to fly in.
As a sensible precaution I would think it unwise to site bees more than 4-6 storeys above ground level or not much higher than the tallest mature trees. This is a height which bees would naturally fly at but not necessarily exceed.
Things to bear in mind when citing bees at height
When siting bees at height on our roof tops we must remember that what is convenient for ourselves may not be the most convenient for the bees who we will be forcing to work much harder and as good responsible beekeepers we should always place the bee’s welfare needs before any needs of our own.
Think about the aspect, what features there are to protect
the hive from wind and rain?
Think about the bee’s access to water. Lugging loads of water from ground level to dizzy heights must be hard work for a bee. Give them a water container on the roof top to make life a little easier for them. I use a poultry drinker with small pebbles in the tray so the bees can climb in and out. This works very well as the bees have access to water, the water won’t evaporate quickly in the exposed environment and the bees can’t easily drown in the water vessel.
Some city rooftops have metal roofs, are lined with roofing felt or other dark materials which absorb the heat of the sun and or reflect the suns glare. Thought should be given to protecting hives from overheating and to protecting the bees from being misled into leaving the hive on cool days if the sunlight is reflected by surfaces onto the hive entrance.
Avoid siting hives near vents, windows or air conditioning units – anywhere bees may explore and enter a building or where equipment may produce vibrations or smells which could upset the bees.
Think about how you will manage your hives natural desire to want to swarm. Swarms produced from high rise hives do either 2 things; they cling to the side of a building often in an inaccessible or difficult to access place or they descend towards ground level where they may bother people. Can you inspect the hives every 6-7 days April to August to ensure swarms are avoided? You could clip queens and keep young queens of a strain of bee with a low swarming index which will make managing and avoiding swarms much easier.
At our Nando’s apiary our hives (which are 3 floors up) face South East, have a wall and row of mature trees protecting them from west and northerly winds and the skylight window openings are covered in fine nylon mesh to prevent bees entering the restaurant.
We’ve also planted the roof top with containers filled with spring flowering bulbs rich in pollen. This gives the bees something to forage on close to the hive early in the year when the wind chill may make it a bit more difficult for them to fly than if they were cited at ground level. Every little helps.
As a responsible beekeeper you should ensure your hives are registered with the National Bee Unit and allow when requested access to the roof top apiary by the bee inspectors. If a bee inspector deems your high rise apiary as too precarious for them to access they can make a reasonable request that you move the hives to ground level for the purpose of an inspection.
One thing to be mindful of is how you will dispose of any hives, bees and equipment should your roof top apiary develop a statutory notifiable disease such as Foul Brood. You can't dig a 6 foot hole in the ground on a roof and you cant light a bonfire either! A government bee inspector can order you to euthanise diseased bees, hermetically seal the entire hive and then have you send it for incineration - at great financial cost to yourself. Do you have sufficient insurance to cover such a scenario? This is something I always make people aware of as it is rarely thought about.
I hope this blog post provides food for thought for those thinking about installing bees at height. I don’t want to discourage rooftop beekeeping but it needs to be done correctly and done with the bees welfare needs put before our own desire for honey (or financial gain!).
Morse and Hooper. 1985 The Illustrated Encyclopaedia of Beekeeping. Dutton Publishing
Breeze et all. 2014 Agricultural Policies Exacerbate Honeybee Pollination Service Supply-Demand Mismatches Across Europe. Journal Plos one
Hive Data supplied under freedom of Information request to National Bee Unit 2015
BBKA membership data provided by BBKA 2015
USA hive statistics available from USDA website
Figures for US city hive numbers is based upon personal communications between city BKA chair persons and beekeeping equipment suppliers.
Hadlock, Charles (1998). Mathematical Modeling in the Environment. Washington: Mathematical Association of America
Bañuelos-Ruedas et al . 2014. Methodologies Used in the Extrapolation of Wind Speed Data at Different Heights and Its Impact in the Wind Energy Resource Assessment in a Region. ISBN 978-953-307-483-2
Thomas D Seeley. 2010. Honey Bee Democracy. Princeton Press. ISBN 978-0-691-14721-5
Gouson and Hughes. 2015. Mitigating the anthropogenic spread of bee parasites to protect wild pollinators. Biological Conservation 191, 10–19
Are Western Honey Bees Apis mellifera really the world’s most important pollinator?
This is the claim made in a recently published paper in the proceedings of the Royal Society of Biological Sciences 10th January 2018. The authors claims are based upon existing published datasets consisting of observations of bees on flowering plants in natural environments around the globe and based upon the abundance of Honey bees recorded during the study have come to the conclusion that they are therefore the most important pollinator in the world.
The claim that a single species can be solely relied upon or referred to as the most important pollinator in the world has been widely criticised by academics who have been quick to point out that many other recent studies show that wild bees are responsible for a greater proportion of the pollination service previously attributed to domesticated honey bees and that in addition there are many crop plants that can only be pollinated by a restricted number of species not including Honey bees. There are also other groups of pollinators which play a huge role in plant reproduction around the world. Moths have recently been shown to pollinate up to 50% of oil seed rape crops in some studies questioning practices of spraying at night to safeguard day flying honey bees.
Globally beetles are the largest group of pollinators by sheer volume. There are over 400,000 species of beetle worldwide (compared to 20,000 bee species) which help pollinate 88% of the world’s flowering plants. Beetles vastly outnumber bees in both terms of species diversity and numbers of individuals. Beetles pollinate many flowers in tropical and desert regions where it is too hot for most bees to survive, they also pollinate many plants who's flowers open at night or which mimic decaying bodies with strong scents.
It has also been quite obviously pointed out that whilst Honey Bees may be the most numerous flower visitors that does not necessarily mean they are pollinating all the flowers they visit. Honey bees are incapable of releasing the pollen grains of many plants so are ineffective pollinators. There are also many species of flower which they visit only to steal the nectar without pollinating at all.
This claim is potentially damaging and could deflect attentions from wild bees who are of more serious conservation concern than the honey bee (which by the way is in no immediate threat or danger and are actually doing ok globally). Relying on a single pollinator such as the Honey Bee for pollination services is dangerous and the loss of diversity of other pollinator species should be of great concern as it could lead to loss of plant diversity should specialist pollinators disappear.
I am a full time beekeeper and lover of the honey bee but simply cannot support the claim made whilst being aware of the complexities of pollination services and awareness of the myriad of other insects which outperform honey bees in the pollination of so many of our valued crops.
As a reminder of the importance of non-honey bees in production of our Food crops I’ve listed below some of our most valuable crop species and the wild bees which help pollinate them.
Pollination by bees
Bees particularly pollinate 87 (or 70%) out of the 124 main crop species grown globally for human food consumption. This contributes to one third of the food we eat. They don’t just provide us with fruits and nuts and vegetables, bees are also an essential element in the production of meat and other animal products.
Bees are essential for the pollination of many herbs, spices and oils used in baking and cooking.
Fish, Meat, Eggs and Dairy products
Most animal feeds contain plant products which are highly reliant on bees for pollination. Without them Diary, meat and egg products would be much harder to produce and would be significantly more expensive to buy.
Livestock reared for meat and milk don’t just graze on grass and cereals. Alfalfa, Peas and Soya beans are primary ingredients in animal pellet feeds fed to Cattle, Sheep and Pigs. In addition Silage and hay containing Alfalfa, clover and other legumes is also an important feed given to cattle. These ingredients are a source of protein essential for muscle growth and production of milk.
Poultry feeds are largely made up of maize and cereals which are wind pollinated but include Soya bean, Alfalfa and Peas (a more sustainable source of protein than Soya) as a protein source. Many poultry feeds given to laying hens contain Calendula petals, the orange pigment encourages brighter yolk colour.
Many Free Range poultry farms include grazing mixtures high in edible herbs for the birds to graze on. These are pollinated by bees.
Cover crops of Sunflower, Kale and other tall herbs designed to provide cover and seeds for game birds and free range poultry rely on bees for pollination.
Commercially reared fish are often fed on a diet of pelletized foods containing Soya bean, Lupine and Oil Seed Rape all pollinated by bees.
Bees essential for pollination of plants used in Animal feeds include the Alfalfa Leafcutter Megachile rotundata , Alkali Bee Nomia melenderi , flower bees Anthophora species which pollinate autumn sown beans and peas, Osmia bees and Bumblebees which work alongside Honey Bees to pollinate Oil seed rape and brassicas used in cover crops and forage crops.
Calendula used in poultry feeds to encourage strong egg yolk colour are pollinated by a number of solitary bees including Lassioglossum Andrena and Halictus species.
Fruits, Nuts and Vegetables
The majority of our fruits and vegetables are reliant on bees to some degree for pollination. Because we grow many crops outside of their native geographical region it is often necessary to introduce honey bees to pollinate them but many crops grown outside their native regions will also be visited and pollinated by locally occurring wild bees. In regions where honey bees are not native ( like the Americas) local crop plants often have their own specialist bee species which will pollinate them.
Members of the Solanum family include Tomato, Potatoes, Yoji berries and Aubergine along with Capsicum ’s like Peppers and Chillies are solely reliant on Bumble Bees for pollination. These plants require sonic vibrations of a specific frequency to dislodge the pollen grains from their tubular shaped Anthers. Throughout Europe millions of Buff Tailed Bumble Bee Bombus terrestris colonies are reared each year to supply poly tunnels and glass houses which grow these fruits. Elsewhere in the world other Bumble Bees are used including the Eastern Bumble Bee Bombus impatiens in North America.
Ericaceous fruits such as Blue Berry and Cranberry are pollinated by a number of bees including commercial managed honey bees. Each year thousands of hives are transported to farms growing these crops but the honey bee is an inefficient pollinator of these fruits. Dense numbers of hives have to be brought in to ensure a good fruit set. Bumblebees are far more efficient at pollinating these fruits and are of significant value. Other bees valuable as a pollinator of Blueberries include the solitary ‘Eastern Blue Berry Bee’ Habropda labriosa . The Blue Berry Mason bee Osmia ribifloris and Anthophora pilipes. The Eastern Blueberry bee is a particularly efficient pollinator of blue berries. Each female bee will pollinate around 6000 fruits in her brief lifetime.
The Rusty Patch BumbleBee Bombus
and Megachile addenda
pollinators of Cranberry, Sadly the once widespread Rusty Patched Bumblebee is
now sadly in steep decline and included on the Endangered list by the American authorities
therefore no longer a viable alternative to honey bee in pollination of
In the USA the most important wild bee in Cranberry pollination is a blunthorn bee Melitta Americana , the females of this species collects pollen exclusively from Cranberry flowers and like bumblebees have evolved the ability to ‘buzz pollinate’ the flower. They are among the most numerous wild bees on large Cranberry farms.
Raspberry are pollinated by a number of short tongued Bumble Bees, Osmia Bees and Honey Bees. In the UK the Buff Tailed Bumble Bee Bombus terrestris , Early Bumble Bee Bombus pratorum and Tree Bumble Bee Bombus hypnorum are important pollinators.
Blackberry are pollinated by a huge variety of insects including bees. Much of London’s honey comes from Bramble as the plant grows along the cities railway sidings and brownfield lands. Aside from Honey Bees other species to pollinate Blackberry include Bumble bees Megachile bees, Andrena Bees , Lassioglossum, Halictus, Hylaeus, Osma the Blue Carpenter bee Ceratina cynea and Xylocopa bees.
Strawberry are widely pollinated by Honey bees and Bumble Bees. The Bumble bee provides more efficient pollination of commercial strawberries leading to larger more uniform fruit set and are also easier to maintain inside poly tunnels and glass houses where Strawberry plants are grown under cover to encourage early cropping. In the open Strawberries also attract Lassioglossum, Andrena, Halictus, Osmia and Nomada bees.
Currants are pollinated predominantly by Queen Bumble Bees since they flower very early in the season.
Gooseberry are pollinated predominantly by Honey Bees but also pollinated by Early Bumble Bee and solitary species such as Andrena fulva .
rely heavily on both Honey Bees and wild bees for pollination. Honey
bees are brought into orchards in large numbers to ensure saturation of the
area with bees and a good fruit set however honey bees are fair weather
creatures and only fly in warm conditions. Many Solitary bees and Bumble bees
will fly in cooler conditions either earlier in the day before temperatures
have risen or during cooler weather when honey bees are reluctant to fly.
Evidence shows that the presence of bumble bees and solitary bees alongside
honey bees ensures a greater fruit set with larger more uniform fruit
Osmia or Mason bees pollinate many orchard fruit crops. Osmia lignaria and Osmia rufra are commercially important pollinators of Cherries, Apples, Almonds, Plums Prunus species. Osmia lignaria is so much more efficient at pollinating Apples that just 300 female bees can perform the pollination role of 90,000 honey bees. Osmia cornuta pollinates Almonds and Osmia cornifrons pollinates Apples and Pears. This bee is important as an important orchard fruit pollinator in Japan where it is responsible for pollinating ¾ of Japaneese orchard fruits and has been spread to the USA to pollinate orchard fruits there. Bumble Bees also visit Apples, Plums, Pears Quince and Medlar. Andrena Cineraria the Ashy Mining Bee can be a notable pollinator of Cherries.
Citrus fruits like Orange, Tangerine, Limes and Grape fruit rely on Honey bees and bumble bees for pollination. Whilst some varieties of citrus are self-fertile and capable of pollinating themselves without bees, fruit set and yields are greatly improved by the presence of bees.
Cucurbits include Melons, Courgette, Pumpkin, Cucumber and Squash. In Europe they rely largely on commercial Honey bees, Wild Bumblebees, Anthophora bees and Halictus bees for pollination.
In addition to these there are Squash Bees of the Peponapis and Xenoglossa genus found in North America. These bees are squash and Pumpkin specialists only collecting pollen to feed their offspring from Pumpkin and Squash plants. The name Peponapis in greek means ‘pumpkin bee.’
Squash bees are solitary and nest in underground burrows often among the crop plants they feed upon. Tillage practices can cause significant damage to their underground nests and non-tillage farming practices have been shown to triple the number of these bees on pumpkin farms. A good population of Squash bees means the farmer can avoid having to bring in Honey bee hives at cost to pollinate his crop. These bees are active very early in the morning from 4am onwards when squash and pumpkin flowers are newly opened and before they have begun to wilt. This habit makes them more efficient at pollinating pumpkin than honey bees which are not active until the sun is up and has warmed the air temperatures. In addition the male Peponapis bees sleep often communally inside Squash flowers where they pick up significantly more pollen than the females do on their brief flower visits. This makes the male Squash bees particularly efficient pollinators of Pumpkin and Squash.
Many tropical fruits
are commercially grown outside of their native
range and are pollinated by managed honey bees. These fruits include Lyche, Longon, Jujubes Avocado
and Passion Fruit
. In Vietnam many of these fruits are pollinated not
by western Honey Bees but by the smaller Asiatic Honey Bee Apis cerana. Apis
cerana reportedly account for 84-95% of pollination in Jujubes and Longans.
Pawpaw or paypaya fruit are pollinated predominantly by nocturnal moths but honey bees contribute to their pollination. Many tropical fruits are also pollinated by Stingless Meliponini bees and Carpenter Bees Xylocopa .
Pineapple do not require pollination to set fruit but they do to set seed. They are predominantly pollinated by Hummingbirds.
Tamarin is a tropical Legume producing long pods containing edible seeds with a pulpy texture. They have many culinary uses including as an ingredient in Worchester Sauce. They are pollinated primarily by the Giant Honey Bee Apis dorsata .
Coconut grow in the tropical regions and are pollinated by native stingless bees of the family Meliponini as well as introduced Honey Bees.
Almonds are pollinated by Honey bees, Bumble Bees and Osmia Bees such as Osmia cornuta . Almonds are the single biggest export of the state of California which grows over 810,000 acres of the crop in vast orchards in the Central Valley. Each year 81 Billion honey bees from 1.6 Million hives pollinate over 2.5 Trillion Almond blooms in what is the largest insect migration on the Planet. Beekeepers truck these bees in from all across the United States on 6000 Lories. Due to the scale of the operation, seasonal nature and lack of alternative forage sources around the Almond groves Honey Bees are the only realistic option for pollination of this crop.
Brazil Nuts are pollinated by colourful Orchid Bees Euglossini species. The females of these bees pollinate a variety of tropical plants as they collect pollen to feed their offspring. The males pollinate Orchid flowers which they visit to collect scented secretions they use to attract the females hence the common name Orchid Bees. Only Euglossini and larger Carpenter bees Xylocopa species can access the flowers as a robust body is needed to force entry into the tightly lipped flowers.
Peas and Beans are members of the Fabaceae plant family. Calliopsis, Protoxeae, Colletes, Caupolicana, Osmia, Anthidium, Megachile, Eucera, Florilegrus, Anthophora and Bombus bees all work alongside honey bees to help to pollinate Beans and Peas globally.
In the UK Beans and Peas are pollinated mostly by Bumblebees, Megachile and Osmia bees. The Hairy Footed Flower Bee Anthophora plumipes is commercially important in the pollination of early flowering peas and beans sown in autumn in regions like East Anglia. It is a hardy bee active very early in the season before Honey Bee colonies are very active and it has a very longue tongue to access the nectar of beans unlike the Honey Bee and short tongued Bumblebees which often damage bean flowers to steal the nectar without pollinating the crop.
Vegetables don’t require pollination to develop the parts of the plant which we harvest and eat but in order to grow them in the first place we need viable seed to sow and bees are essential for this.
Brassicas include Cabbages, Mustard, Oil seed Rape, Turnip, Kale, Cauliflower, Broccoli and Sprouts are pollinated by a wide range of insects including Anthophora Bees, Honey Bees, Bumble Bees and Osmia Bees.
Carrots, Fennel, Parsnip and Parsley are pollinated by many small solitary bees from Andrena, Colletes, Hylaeus , Nomada and Lassioglossum species. Hoverflies and pollinating beetles also play a significant role in pollinating these vegetables. Larger pollinators like Honey Bees and Bumble bees are poor pollinators of these crops. The Carrot Mining Bee Andrena nitidiuscula is solely reliant on Carrot for pollen to feed its offspring.
Onions. Allium flowers are popular bee forage and visited by a wide range of bees. In the US a small mining bee called Andrena prunorum is one of the most efficient pollinators of commercially farmed onions whilst in Europe the Onion Yellow Faced Bee Hylaeus punctulatissimus collects its pollen exclusively from onions and . This species is sadly thought to now be extinct in the UK. London appeared to be the species last stronghold in the UK prior to its extinction and the last specimen was seen foraging on cultivated onions in a Chelsea garden in 1827. Celery is pollinated by many Solitary bees as per carrot.
Beets include the sugar Beet, Beetroot and Leaf Beet or Chard. These are all pollinated by Honey Bees and many solitary bees.
Potatoes belong to the Solanum family and are closely related to Tomato. The part of the plant we eat is the tuberous root and not a pollinated fruit as with other Solanum crops but bees are necessary to breed new varieties of potato unless they are hand pollinated. Like other Solanums Potato have flowers bearing cylindrical pollen holding apparatus which very few bees can access. In order for the flowers to shed their pollen they must be sonically vibrated at a specific frequency. Bumble bees and a select few solitary bees have evolved the ability to do just this by revving their flight muscle out of gear vibrating their bodies.
In the USA Anthophorula and Exomalopsis bees work alongside Bumble Bees to pollinate Potato and other Solanum crops.
Sweet Potato are members of the Morning glory ipomoeae family and pollinated by several bees in the Melitoma genus but one bee in particular is important as an efficient pollinator of these plants, Wild Sweet Potato Bee Cemolobus ipomoeae . This bee is the sole species in a unique Genus of bees with unique adaptations to pollinate Ipomoeae flowers. Once common and widespread across North America it is now in rapid decline and threatened with extinction.
Most of our common culinary herbs are pollinated by solitary bees and Honey Bees and short tongues bumble bees. These include Basil, Coriander, Oregano, Sage, Mint, Thyme, Lavender, Chives, Rosemary and Bay Lorrel.
Saffron the most expensive herb comes from an autumn flowering crocus Crocus sativus . They are pollinated by bees which visit them to collect pollen to feed to their offspring.
Vanilla comes from the fruiting pods of a climbing tropical orchid which is pollinated by several species of tiny stingless bees of the Meliponini genus. These bees are social forming a large colony not unlike a Honey bee and also produce honey. Stingless bees are valuable pollinators throughout tropical America. Outside its native range Vanilla is commonly grown in Madagascar where it is largely hand pollinated.
Cardamon is pollinated by Honey Bees.
Allspice Pimenta diotica is grown commercially and pollinated by Honey Bees however coming from the west Indies and Central America where Honey bees are not native they are likely pollinated by the native solitary and stingless bees.
Nutmeg comes from a tropical tree in the magnolia family. Magnolias are ancient forms of flowering plant and pollinated by primitive pollinators the Thripes, Beetles and Flies.
Star Anise Illicium verum is pollinated by Beetles.
Coffee comes from 2 species of plant. Arabica Coffee is a self fertile plant but pollination by Honey Bees improves yields and fruit set. Coffee robusta is an inferior coffee and dependent upon bees for pollination. 33 species of wild bees pollinate coffee beans.
Tea comes from an evergreen bush in the Camelia family. Its flowers are pollinated by bees.
Chocolate comes from the fruit of the Cocoa plant. Cocoa plantations support a wide variety of bees but appear to be mostly pollinated by tiny midges.
In addition to food crops wild bees pollinate many of our wild plants in the wider environment and also plants important to man for use in the manufacture of fabrics, and clothing like cotton.
This month’s forage blog takes a different direction. There’s not much to write about in terms of seasonal forage for bees in the depths of winter when little is in flower and our bees are dormant so for a change my blog takes a look at what we can do to make our gardens better environments for bees all ear round going forward into a new year.
Create Habitat for bees
Bees need places to forage and find pollen, nectar, water and propolis and this can be done by planting the right types of flowers for them and incorporating a small water feature into your garden where bees can gather water.
Another sort of habitat bees need is nesting habitat where they can raise their offspring. For Honey bees this is a hive but for other bees this can be piles of decaying logs for them to excavate a nest burrow, a patch of sandy soil or clay bank for mining bees to dig out a nest tunnel or bundles of hollow plant stems and cardboard tubes for the likes of mason and leafcutter bees. These nesting habitats can be conveniently catered for in the form of the many pre-fabricated bee nesting boxes available from garden centres and online shops or you can make your own – see my guide ‘how to make homes for solitary bees’ here: http://www.apicultural.co.uk/contact
Other ideas you could try include making a nesting cylinder for ground nesting bees. You need to invest in a sheet of perforated metal sheeting which you bring together at the ends and fasten together with nuts and bolts to form a cylinder. This is then filled with sand and or free draining soil to provide a medium which bees can burrow into. This design allows bees to nest in the top of the planter by burrowing downwards but they can potentially also excavate lateral burrows entering through the many perforated holes in the metal sheet. Try using soft and sharp sand, cactus compost or John Innes loam based soil with added sand. You can plant drought tolerant flowering plants in the top too to provide cover as some bees prefer some vegetation cover near their nests whilst others prefer a more open aspect.
Lastly the final habitat that bees need is over wintering habitat. For bumble bees this is often a shallow hollow excavated in dry soil beneath tufts of grass or piles of decaying vegetation, compost heaps or for solitary bees hollow plant stems. Try not cutting back all your herbaceous perennials in autumn and leave some stems intact for insects to hibernate inside the hollow stems. Many solitary bees over winter in their nest chambers.
Plant useful things in your garden
At Apicultural our gardening mantra is either the bees can eat it or we can. If a plant can’t fulfil either of these two requirements then it doesn’t get a look in! Of course most of the things that we can eat are also beneficial to bees and other pollinators as the majority of vegetables do also flower and the fruits we eat need the bees to pollinate them.
Plant the best plants for bees
Not all flowers are equally attractive or beneficial to bees and other pollinators. Attractiveness and benefit to pollinators varies a great deal with some plants being 100 times more attractive and useful than the worst. To complicate things not all plants are equally beneficial to all insects due to the shape and morphology of the blooms which may prevent all but a few dedicated visiting bees whilst others contain toxins which only certain species of bee are immune to the effects of. Great examples are the foxglove Digitalis Purpurea , Comfrey Symphytum officinalis and Everlasting Pea Lathyrus latifolia which are among the top 10 UK plants for Sugar content in their nectar and the amount of nectar produced per hectar (kg of sugar/ha/year). These 3 plants should be a magnet for all bees having the greatest rewarding nectars among British Plants. However Fox Glove and Comfrey are plants with deep tubular flowers which prevent all but the longest tongues from accessing their nectar meanwhile Everlasting Pea has both a deep nectary and tightly lipped flowers which require a long tongued bee with a robust body to enter.
Bulking up your gardens by planting the most attractive and beneficial plants for a broad range of insects will provide the most benefit to pollinators whilst adding plants which are attractive or of benefit to only a small number of species helps provide food for more fussy specialists. There are many bees which are not generalist and will only feed their offspring pollen from a small number or a single species of plant. Plant a mixture of broadly attractive and specialist plants and choose plants which will offer flowers over a long season or plan a succession of flower types throughout the season.
As we progress through December the vast majority of the UK’s bees are well tucked away for winter.
The majority of our bees are solitary and the most of these bees die in late summer leaving behind their offspring entombed deep inside underground burrows or imprisoned inside hollow plant stems or decaying wood. These bees will either overwinter as a pupae, pre-pupae or as a fully mature bee but they will not vacate their birth site until spring with the advent of warmer weather.
This year many seasonal species of bee have been spotted on the wing and visiting garden flowers well into autumn. These Include Andrena scotica, Andrena haemorrhoa, Andrena nitida . These are spring species which have either been disturbed resulting in early emergence or they have been tricked into emergence by the deceptively warm temperatures in the Autumn. With the arrival of hard frost and prolonged snow these will have now perished and won’t be seen again until their proper time of emergence in early spring.
Whilst enjoying your Cranberry sauce this Christmas spare a thought for the plight of this little chap, Bombus affinis - the Rusty Patch Bumble Bee.
An important pollinator of Vaccinium including Cranberry and Blue Berry, the Rusty Patch Bumble Bees form large colonies with up to 1000 workers per nest - far larger and longer lived than other bumble bee species meaning a single colony can facilitate more pollination than other species.
Cranberry and Blueberry like other members of the Vaccinium family are poorly pollinated by most bees including Honey Bees. Growers have to ship in lots of Honey Bee hives to saturate the crop in order to guarantee a good fruit set. Rusty Patch Bumble Bees along with other Bumble Bees and a handful of Solitary bees including the Cranberry Blunthorn Bee Melitta americana have evolved to perform buzz pollination and are important pollinators of these plants. These bees can sonically vibrate their bodies by revving their thorax muscles to shake pollen loose from the flowers. Flowers in the Vaccinium family are reluctant to give over their pollen grains to other types of bee as similarly to Solanums the pollen is held inside cylindrical apparatus which does not yield pollen freely.
Sadly the Rusty Patch Bumble bee is now facing extinction.
In the last decade its numbers have plummeted by 95%. Once one of the most common bees in the mid-west and Eastern United States and Canada its range has been reduced by an enormous 80% and is now found in just a few tiny pockets of habitat. European Bumble bee diseases such as Nosema bombi are thought to be the cause behind their decline – this and other European bee diseases were accidentally introduced to North America on imported Buff Tailed Bumble bees from Europe which were used to pollinate tomatoes in glasshouses. Being a naive host to European Bee pathogens the Rusty Patch Bumble Bee was quickly overwhelmed. Scientists believe that due to the speed with which this bee has declined the cause can only be due to an extotic pathogen. Even populations in mountain forests far away from pesticide treated crops have been badly affected.
In 2015 the International Union for the Conservation of Nature (IUCN) recommended that the Rusty Patch Bumble bee be added to the Critically Endangered Red List.
There is now an ongoing battle with the Trump Administration to see through protection measures necessary to ensure the species survival. Right Wing US politics have the potential to compromise conservation measures.
The decline of the Rusty Patch Bumble Bee serves as a reminder of the consequences of living in a global society filled with international trade and the movement of plants and animal materials around the world which peaks around Christmas time.
The Christmas Wreath
Christmas wreaths predate Christmas and Christianity by several thousand years. Originally ancient Britain’s and other northern Europeans would have made loose hanging wreaths (basically just a bundle of greenery tied at the top and hung from the walls of their home) as a means to warn off winter spirits. It is only later with the rise of the Christian churches that Wreaths adopted a circular shape mirroring the crown of Christ. Our ancestors believed that evergreen plants were magical because unlike other plants they didn’t die back and shed their leaves in winter. Additionally many evergreen plants like Holly produce long lasting berries which were a symbol of life and fertility. Plants like Ivy who’s berries persist long into winter as well as being evergreen climb and entwine representing matrimony and togetherness. Strongly scented sprigs of conifer would have hidden the foul odours of winter (no fridges back then so perishable foods would not last long even when dried and salted and would produce a pungent smell)
Key items used in wreaths include Holly Ilex aquifolium which is pollinated by Honey bees and Andrena mining bees who’s short tongues are well equipped to manipulate the strongly scented but visually insignificant flowers. Ivy flowers are pollinated by a wide variety of insects and are a valued autumn forage source but has its own special pollinator the Ivy Mining Bee Colletes hedera which only collects pollen from Ivy and times its emergence to the opening of the Ivy flowers.
The bee Apocalypse
I’m sure I am not the only person who’s fed up of hearing or reading about the looming bee apocalypse?
All too frequently mis-informed journalists are spitting out articles which help perpetuate the myth that our honey bees are facing imminent threat of extinction.
Just this week I’ve read 3 different articles which refer to the UK losing 1/3 of its honey bee colonies this past year and several others referring to 40% losses in the USA resulting in honey bees facing possible extinction. However none of them cite the source for the information which raises the question of the validity of their statements. So where is the evidence?
I’m also getting quite fed up with the fictitious quote supposedly made by Einstein being quoted which wrongly says “If the bee disappeared off the face of the Earth, man would only have four years left to live.” The fact is there is absolutely no evidence that Einstein ever made this statement, and even if he did it’s not true – whilst true without bees we would see a reduction in pollination services leading to higher food prices and a reduction in food crops, we would still have other pollinators and the many foods which do not require insect pollination. Bees particularly pollinate one or more cultivars of over 66% of the world's crop species and contribute to one third of the food we eat. So food would be more scarce and more expensive but not gone.
The facts are Honey bee numbers are actually on the increase globally!
In the UK hive numbers have increased as more and more amateurs take up beekeeping. Membership of the British Beekeepers Association has risen from 8,500 in 2008 to over 25,000 in 2017 and it continues to climb. In Cities like London numbers of honey bee hives have more than doubled in the past decade to over 5,100 hives in 2017 according to the National Bee Unit. Nationally colony numbers have grown to over 147,000 hives in England and Wales.
Meanwhile in the USA the US Department for Agriculture has stated that hive numbers in 2017 are the highest they have been in over 20 years as resourceful beekeepers maintain numbers despite severe winter loses in some years.
In New Zealand numbers of hives have increased by 30% to meet rising demand for Manuka honey. 30 years ago New Zealand’s beekeepers struggled to give Manuka honey away before it was discovered to have high antibacterial properties. The situation is similar in China and across Europe.
Honey bee populations are stable for now and out of any immediate danger (if they were ever in any immediate danger at all). Whilst our honey bees and their keepers still face a difficult future dealing with Varroa mites and other exotic pests they are in no way under any threat of extinction or apocalyptic die offs and sensational journalists perpetuating the myth are just unhelpful and counter productive.
The situation for Many of Europe’s trees on the other hand is looking very bleak.
The tree apocalypse
What not enough people are not talking about is the future of the UK’s trees.
In the 1970’s Dutch Elm Disease spread throughout the UK decimating the nations magnificent Elm Trees. Once among our largest and grandest trees Elms have been reduced to a scattering of immature specimens which seldom reach full maturity before they succumb to Elm Disease.
In recent years Chalara otherwise known as Ash Die Back caused by the fungus Hymenoscyphus fraxineus has been spreading rapidly through the UK’s Ash trees.
Experts predict that within a generation the native Ash tree will be no more. An article published last year tiled ‘ashes to ashes’ sums up the predicted fate of our native Ash trees perfectly. Even if a handful of Ash trees develop a resistance to Chalara they are still facing doom and gloom from the exotic beetle pest the Emerald Ash Borer. The beetle native to Asia was accidentally introduced to North America probably in the 1990’s and has decimated Ash trees wherever it becomes established. Whilst not in the UK yet experts believe it’s only a matter of time before the pest arrives here.
Ash is an important broadleaf tree in the UK, the second most commonly planted genus, and makes up nearly 15% of all broad-leaved woodlands. The character of the British countryside would be changed forever should Ash disappear from the landscape. To prevent the spread of Ash Die Back the species is currently under a movement ban with no nurseries or growers allowed to stock or sell the plant.
Another iconic British tree under imminent threat is our Native Oak Quercus robur. In recent years a deadly disease known as sudden Oak Die back caused by a fungus like pathogen Phytophthora ramorum has been spreading through Oak woodlands of Southern England. The pathogen causes bleeding cankers on the trunk, necrotic stem lesions, leaf blackening, branch die back and eventually complete de-foliation of the tree resulting in its death.
Phytopthora is not limited to Oaks. As well as all Quercus species the disease also effects Rhododendron, Viburnums and Camelia’s widely grown in parks and gardens throughout the UK.
In addition to Phytopthora Oaks are also under attack from the invasive Oak Processionary Moth. The pest is now entrenched in parks and woodlands in South West London and continues to spread. The situation has meant that all movements of Oak trees and other high risk Phytopthora hosts now require plant pass porting and the notification of the Governments Plant Health Unit.
Other diseases effecting UK trees include the Sweet Chestnut Blight Cryphonectria parasitica and Xanthomonas arboricola pruni - a pathogen which causes bacterial leaf shotting and stem cankers on Prunus species. These pathogens are currently found in several European Countries and have been intercepted on a number of occasions on imported plants recently arrived in the UK.
One of the more frightening pathogens not yet found in the UK but currently infecting parts of France, Italy and Spain is Xylella fastidiosa. This highly contagious bacterial infection has been classified as one of the most harmful plant pathogenic bacteria in the world. The bacteria is spread by sap sucking insects such as leaf hoppers feeding on host plants and spreading the bacterial spores. The bacteria has an ever growing list of host plant species but currently extends to over 150 plant genera including Oak, Elm, most UK broadleaf trees, Citrus, Lavender and herbaceous plants. As well as horticulture, forestry and natural habitats Xylella has the potential to devastate UK agriculture crops worth over £24 Billion annually.
Xylella is subject to EU
emergency measures and in October 2017 the European Commission approved increased
protection against the risk of Xylella spreading.
The new measures include strengthened movement requirements on high-risk plants, and require quicker responses to suspected findings of the disease.
If an outbreak were to occur in the UK the response could mean the destruction of all host plant material within a 5km radius of the outbreak potentially leading to loss of precious natural habitats, Farmland laid to ruin and horticultural businesses suspended. Entire rural communities reliant on those industries could be lost.
The consequences are frightening. It’s the stuff of science fiction.
There are currently dozens of statutory notifiable plants pests and pathogens spreading through Europe which could spell disaster for UK trees should they become established here.
So far this blog has focused mostly on pathogens but next we come to one of the most serious insect pests to invade the UK – The Asian Longhorn Beetle Anoplophora glabripennis . This impressive beastie (think stag beetle size with very long antenna) lays its eggs on broad leaf trees where its larva burrow into the woody material leaving behind a swiss cheese like honey comb of tunnels which weakens the tree and eventually leads to its death.
The beetles were found in 2012 in Paddock Wood near Maidestone in Kent and the entire area is now under close surveillance to try and prevent its spread. If this serious pest were to become widely established in the UK it could be the final nail in the coffin for our besieged native trees.
So whilst our Honey bees are doing fine for the time being were not having nearly as much discussion as we should be about the threats to the nation’s trees and woodlands which are facing numerous threats on all sides.
Forget the bee apocalypse it’s the impending tree apocalypse that we need to be concerned about.
More information on threats to the UK’s trees can be found on the Forestry Commission and governments Plant Health Agency websites.
Whilst in Atlanta I attended the Metro Atlanta Beekeeping Associations monthly meeting and lecture. I have a few friends there among the association and whenever I come to town I get invited to attend their meetings, meet their members and exchange beekeeping experiences.
Their October guest lecturer was the internationally known Dr Keith Delaplane MBE from University Georgia. See his profile here: http://caes2.caes.uga.edu/bees/personnel/delaplane.html
Before the meeting my friend Cindy, former president of the association introduced me to Keith who has previously worked on bee research projects in the Uk with current colleagues of mine at FERA/DEFRA. We had a brief chat about the work Keith participated in and my colleagues he'd had the pleasure of working with.
As the room packed out with around 50 people attending Dr Delaplane began to gave his talk on his latest research project which has just been funded by the United States Department for Agriculture.
He started off by explaining some of the background of honey bee social evolution and Honey Bee reproductive strategy and how having a single queen devoted to reproduction within the colony brings benefits to the hive. He went on to explain that having highly promiscuous queens which practice polyandry also brings benefits through the diverse genetic make-up of the colony which enables the colony to brave environmental stressors, be more disease resistant and produce more honey.
His latest project will involve the artificial insemination of a large number of queen bees from various stocks. These queens will be inseminated in 3 groups. One group will be given the sperm of just 10 drones, another group the sperm of 30 drones and the last group the semen of 60 drones. The researchers will then compare the colonies performances against varroa resistant hygiene, Productivity, disease etc. Their hypothesis is that instrumentally inseminated queens with a more diverse package of sperm will produce more productive colonies.
At this point he pointed out that the queens receiving sperm from 60 drones will not burst with semen because they are too full! The sperm from multiple drones is blended together then the same amount of the mixture given to each queen. Apparently he’s been asked if queens burst if they are full on several occasions.
Dr Delaplane explained that within each colony there exists sisterhoods made up of workers belonging to the same drone father. These different sisterhoods made up of super sisters often display a preference or exceptional ability at certain tasks within the hives. Some may be better at foraging, others better at producing wax or comb construction, whilst others may be better at brood rearing and others may be more inclined to swarm. Having a diverse workforce means you have more sisterhoods with task specialisms that are well equipped to excel at a wide range of tasks within the colony therefore the colony can survive and thrive easier.
This is the exact opposite of what happens in most bee breeding programs when beekeepers are selecting a small number of drones to inseminate queens as they are looking for a specific set of desired traits. Dr Delaplane believes that rather than selecting for specific traits we should be aiming for queens which have slept around allot and produce a diverse workforce which in itself produces better bees.
He also explained that among the sisterhoods in the hive there are some bloodlines which are royalty and do not make good workers. These bees when they are larva emit a pheromone which screams out to the nurse bees ‘make me a queen’ and in the event the the colony needs to make an emergency queen cell its these larva which are chosen over others as preferential queens because they are genetically programed to be better queens but poorer workers. As workers these bloodlines are basically social parasites and do little to no work in the colony. This was the first I had heard of royal bloodlines in the Honey Bee and had always thought queens were chosen at random or that the bees somehow can tell which larva are fittest and chose them.
It had for a long time been widely hypothesised that sisterhoods would prefer a supersister to raise as the next queen as that super sister queen would share more DNA with her sisters but this has turned out to be one of the biggest scientific flops of the 20th century with over 100 studies failing to prove this is what happens.
So it turns out some queens are born to be queens – but may never become one and others which are not ‘born to be queens’ just happen to get laid in a play cup and become a queen anyway without any particular desire or choice to become one.
Dr Delaplane thinks his new research project could challenge established practices by bee breeders and queen producers forcing them to re-think the trend of selecting a narrow range of desirable traits which produces genetically limited stock.
My own preference for raising new queens is the miller method or I use a special frame inside the parent colony which then snaps apart into several smaller frames fitting into a mini mating hive populated with nurse bees and I leave the bees to decide which of the larva they want to raise into queens. Its less work than grafting and providing you supply the nuc with a frame consisting plenty of eggs or very small newly hatched larva for the bees to choose from they have plenty of time to feed the larva royal jelly and make good queens.
I find that this method works for me better than grafting or using the jenta cup system which I have also experimented with. I get great queens using this method and I think my results coincide with Dr Delaplanes findings thus far.
Late summer for the bees is one of the most desperate times of the year when they can struggle the most to find enough food to eat. Many people find this fact difficult to believe as the weather is often hot and sunny and presumably great for the bees but it is in fact often one of the leanest times for the busy insects. At this time of year colonies are large with many mouths to feed and as the beekeeper has removed the honey crop the flowers are also diminishing in abundance meaning the bees can struggle to replace honey which has been taken off. For this reason it’s crucial not to be over greedy and take all the honey leaving the bees with no stores for themselves.
Come late summer the majority of our nectar rich native wild plants have ceased flowering and gone to seed, especially woodland and meadow flowers whose flowering period is in rhythm with the closing of the woodland canopy and cutting of meadows for hay. Bramble and all our native trees have also long since finished flowering and are now sporting fruits and seeds leaving little for the bees.
Away from Heather moorland and Heaths, the only real bountiful sources of forage from native wild plants are Greater Willow Herb, Thistles, Ragwort, Bindweed and Hogweed – though many of these are early this year and already going over. Along water courses Purple Loosestrife, Marsh Woundwort, Water Mint and the invasive Himalayan Balsam provide welcome relief but not everyone is in range of such localised sources of forage.