One of the things I have been very interested in during my travels throughout the United States was investigating how different urban areas compare to London in terms of forage availability. To begin my comparison we first need to understand what we have here at home in London.
Here in London we have very high hive densities in some parts of the city. According to 2016 figures from the National bee Unit Greater London has around 5000 hives and around 1400 beekeepers. The exact number is unknown as it is estimated that 25-30% of beekeepers do not register. With this in mind the actual number of managed hives in Greater London could be as high as 6200. NBU data also shows that in some central London areas hive density is as high as 13 hives per square kilometre – greater than many rural areas. Unlike many rural areas which have vast swathes of agricultural crops which provide a limited variety but seasonal super-abundance of nectar, London has less abundance of forage but a greater variety due to the wide range of exotic plants grown in the city’s parks and gardens. What this means for bees and beekeepers in London is that our bees have a much more balanced and varied diet offering them a wider range of nutrition but our honey crops generally fall 30% short of the UK national average. According to the BBKA honey survey results for the past decade London has consistently been the lowest yielding region in the country in terms of average volumes of honey produced. The exception to this trend has been 2015 and 2016 when national averages plummeted due to the cold, wet and windy spring weather but London yields remained the same (due to our microclimate and more stable weather patterns)
London is 61 percent green space by land area. Of this 14% is domestic garden green space, 38.4% is public green space and the remaining is made up of commercial green space, railway sidings, brownfield land and green roofs according to data from Green Space Information for Greater London (GIGL), The General London Assembly (GLA) and the 2012 World Culture report.
London also has an abundance of trees with tree canopy covering 21.87% of the city. In 2003 London had around 7 million trees – almost as many trees as there are people and there are targets to increase this by 5% by 2025. Under the Mayors RE:LEAF initiative 75’000 new trees are planted in the City each year. On the surface London is a pretty green city but when we look more closely at the available data we begin to see that some parts of the city’s green areas are little more than green deserts. According to Kew Gardens around half of London’s half a million street trees are sterile London plane trees, as are many of the trees in central London parks. These sterile hybrids offer no pollen or nectar for pollinators and much of our parks these trees grow in are also largely short cut grass with few flowers for bees. Increasingly urban planners are planting birch and alter trees because they grow rapidly, take up little space and are low maintenance and tolerate the poor, dry urban soils. These trees offer no pollen or nectar for bees.
Generally speaking the green spaces closer to the city centre tend to offer less foraging opportunities than those further out which are often more wild and rugged and contain more wild flowers. Further out we have more large habitats including heaths and commons which are less intensively managed. Also further out into the London suburbs more of our railways are above ground and lined by thickets of Bramble, avenues of trees and more of the road verges include green buffers. There are exceptions, the gardens at Buckingham palace for example are known to have a rich diversity of flowering trees including wilder areas. For some time there has been a growing concern that in some areas of the city we may have reached saturation point where numbers of hives has reached the limits of what local forage can support. It is this concern which is leading many organisations including LBKA to promote the planting of flowers and trees for bees. There are now a number of initiatives such as river of flowers and bee lines project which aim to create landscape scale bee friendly corridors of suitable flower habitat through parts of the city to link up pollinator populations and help provide forage for bees. On the whole though London is a good place for bees, and is by no means a bad habitat for bees but as I discovered on my travels there is much room for improvement and some of the US cities I visited put us to shame when it comes to providing habitats for pollinators.
Many US cities contain far more green space than London. Much of the green space in US cities is private, few cities in the US can match London’s 38.4% public accessible green areas. Some cities Like Atlanta have very little public green space at just 6%, New York has 14% and Washington 19% but overall when you include domestic gardens and privately owned land the amount of green space within most US cities is substantially larger than what we have here in London, largely because US houses tend to have enormous back gardens. If you look at the City of Atlanta from the air for example you see a vast sprawling city made up of extensive suburbs, the houses surrounded by vast gardens containing many mature trees. There are also numerous golf courses, country clubs and wooded plantations.
It’s not just the amount of green space that maters but the quality of the green space and this is what in my opinion makes many US cities far more desirable habitats for bees than London. The vast majority of US cities have much higher tree canopy percentages than London, the US average for a typical city being 27% tree cover. New York for example, despite having less green space than London overall and being far more densely built up contains far more trees per square mile than London with tree canopy covering 24% - a large percentage of these trees are flowering trees useful to pollinators. Washington DC is 36% tree cover, also mostly flowering species and at the top of the list is Atlanta with 36.7% tree canopy.US cities also contain fewer sterile plane trees and a higher proportion of flowering trees of use to pollinating insects than UK cities. For example just 13% of New York’s trees are London Plane ( https://tree-map.nycgovparks.org/ ) and Southern states have even fewer still. In place of Plane trees we find Native Maples, Tulip Poplar, Linden and Locust bean trees. All of these trees are native to the Eastern United States and are prolific sources of forage for bees. Much of Atlanta’s urban tree population are Tulip Poplar which provide a banquet of nectar in spring.
Of course these cities are not all the same size as London so my comparison here is focussing on canopy % as gleamed from the US Parks Score Index and world culture report 2012. Trees make a huge difference to bees in terms of the amount of honey they can produce. A large mature tree when in bloom can contain the flowers equivalent to an acre or more of ground level blooms. For example a mature Cherry can produce 2 litres or more of nectar per day.
Americans appear to be much more relaxed about having large trees growing close to their houses. There is far less tendency in the US to heavily surgeon and prune trees growing close to residential properties, people are far less worried about the shade caste by trees – possibly because during the long very hot summers there, shade provided by trees dramatically helps to keep urban areas cool.
Americans are also much less concerned about the autumn leaf fall these trees produce. Here in London we butcher our urban trees on a regular basis so they don’t grow to their full potential or produce the same abundance of blooms that trees in US cities do. So it is the greater abundance and the choice of trees planted in US cities which I think makes many US cities much more desirable places to keep bees than much of London.
Another element which makes US cities desirable places to house bees is that most have far fewer urban beekeepers than what we experience here in London. As mentioned in my part one instalment, keeping of bees in urban areas is often strictly regulated in America and many cities until recently banned the keeping of bees so the number of keepers in most cities in America falls well below that of what we have in London. In New York the New York City Beekeeping Association estimates that there are around 50-100 keepers and a combined 400-600 hives within the city, most of which belong to a handful of individuals. Washington DC has even fewer still at around 200-400 hives as their ban was only lifted in 2013. One exception is Atlanta Georgia. According to conservative estimates from the main beekeeping equipment supplier for the area there are around 2000 beekeepers in the greater Atlanta area and around 5000 hives. This increases if you go further out to include the entire Metropolitan area and surrounding counties. Atlanta is a very green city with plenty of forage for bees but like London has recently witnessed a dramatic increase in number of new hobbyist beekeepers. The association there takes on twice the number of beekeeping students on its spring courses as LBKA does and they are also keen to spread the word that the public can help bees the most by planting for them. Even still Atlanta is no comparison to our situation In London because it is a much greener city with substantially more forage. From what I have seen no US urban centre compares to our situation in London regarding forage availability vs numbers of hives.
Urban Pollinator habitat initiatives in the US
During my travels I came across some great examples of urban greenspace regeneration that is contributing to conserving urban pollinators and providing substantial urban forage for bees. My favourite, purely because of its high contract of lush greenery and tranquillity against the surrounding canyons of sky scrapers is the New York High Line.
The high line
The high line is a 2.3km stretch of elevated railway line that had been abandoned and transformed into the Cities newest public park. It floats 1 storey above street level above the hustle and bustle of the cities Lower west side and forms a strategic green corridor from Chelsea to Hells Kitchen. The entire park has been designed and planted with native planting in mind and features many prairie plants almost all of which are beneficial to bees. Sections of the high line include prairie meadows, grasslands, scrub and pioneering woodland. During my visits to the Highline in 2011, 2014 and 2015 I saw an abundance of honey bees, Native Bumble bees and Leafcutter bees visiting the flowers. Alongside them were Monarch butterflies heading south to their wintering grounds in Mexico. The highline is a fantastic example of how a disused space in one of the most populated cities in the world can be transformed into a beautiful urban oasis for both people and wildlife. The park has a really useful website which includes a calendar showing visitors what is in flower at any month of the year. Several beekeepers keep hives close to the park and their Italian bees can be seen in abundance on the flowers gathering forage. http://www.thehighline.org/
Atlanta Belt line
I discovered a similar but much larger urban greenspace project in Atlanta. It’s called the Belt Line and it’s a 22 mile long disused railway encompassing the entire city centre. Still under construction it will be some time before the entire park is completed and open to the public but once finished it will provide green transport links, affordable housing on former brow field land, new urban greenspaces providing a valuable outdoor leisure resource for local people but also form a strategic wildlife corridor for city pollinators and other wildlife. The belt line will link almost all of the city’s existing green spaces together by passing either through them or very close to them linking isolated habitats to one another. Much of the length of the new park is being planted with native prairie plants and new native woodlands. I visited a recently completed section to the north of Piedmont park where the Atlanta Botanical Garden staff have recreated native meadows full of plants which to me were very familiar as I grow them in my Garden. Flowers like Perennial Sunflower, Echinacea, Rudbeckia, Gallardia, Liatris, Monardia, Coreopsis and verbenas. The entire park is to be designated as a regional arboretum. http://beltline.org/
In my next instalment I shall cover some of the pests and problems faced by US beekeepers and their bees.
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.