Thursday 16 July 2015

The Honeybee: A False Idol?






Thanks to recent media attention, most of us don’t need telling about the importance of bees and their plight in the modern world.  Along with other pollinating insects, they are responsible for providing us with one third of our crop types from plums to pecans and peppers to pulses, a voluntary workforce that pollinates 80% of wild plants in Europe1 and is worth over £500 million of crop production a year to the UK alone2. Humans have rewarded them poorly with a combination of pressures including poisoning with pesticides, infection with imported diseases and destruction of their homes through habitat loss, causing terrible declines in their numbers.

Bees have climbed the PR ladder from a perceived stinging nuisance to some of the world’s most famous and cherished ambassadors for insect kind. So great has public support been for these insects that the UK government has taken a stand by passing the National Pollinator Strategy in November 2014. The realisation of the importance of bees to human wellbeing, and the impacts of humans on bee wellbeing have made bees poster children for the environment,  our reliance and our impacts on the natural systems that support us.

But there is confusion over the exact identity of this pollinator poster child. The classic image of a bee is the yellow-and black striped, dumpy flier of children’s drawings, resembling many Bumblebees. Popular culture has presented these friendly, fuzzy insects as the filler of our honey jars, fostering the perception of ‘the bee’ as a single, honey-making entity.

In truth there are lots of types of bee and only the balder, more wasp-like honeybee makes the sweetness that fills our shelves.  This confusion of two familiar kinds of bee means that ‘bee’ and ‘honeybee’ are often given the same meaning.  Many newspaper, magazine and online articles on bee declines and conservation make this mistake, creating further confusion by leading to the belief that reversing pollinator declines is all about protecting our honeybees.

An otherwise pleasing advert for Kellog’s honey cornflakes wrongly depicts bumblebees as the workers producing the honey. Bumblebees do not produce true honey.




Getting it half right. One third of our crop types rely on pollinators, but not solely on honeybees as is often suggested.

This idea is perpetuated by many beekeepers, keen to preach the virtue of their charges (though unfortunately few know much about the honeybee’s wild cousins). This bias even reaches the official level; The UK’s first Bee Summit was mainly focused on the honeybee and industry tests on the effects of pesticides on pollinators are only performed on honeybees. In reality, honeybees are only a small part of the big picture. The true situation is well illustrated in this video by DEFRA for The National Pollinator Strategy
 


So the idea of a single bee species is incorrect, but what does this mean for the protection of our pollinators and our food supply? There are three main issues with the idolisation of the honeybee above its relatives:

1.UK Honeybees are a single species amongst many

There are several species of honeybee, but only one lives in the UK, the Western honeybee (Apis mellifera)*. This is not a species of conservation concern (i.e. it is not particularly threatened). Compare this to their British neighbours, 25 Bumblebees (7 of conservation concern) and around 260 diverse and little-known solitary bees (64 of conservation concern)3. Bees are also just part of at least 1500 species of pollinating insects in the UK4. The honeybee is far outnumbered by other species with radically different lifestyles, habitat requirements and flower preferences which need taking into account if we are to conserve our pollinator task force. 

* Only one honeybee subspecies, the Black bee (Apis mellifera mellifera) is a UK native and is receiving recent attention as it has some resistance against the devastating Varroa mite. Most UK honeybees are a complex of continental subspecies bred for their honey yields.


The ‘Busy Bees and their Cousins’ by Maude Scrivener illustrates the diversity of Britain’s bees including the Honeybee (Bottom right), Bumblebees, Leafcutter bee, Nomad bees (middle) and other solitary bees (Alongside two ichneumon wasps in the upper right corner).

 

2.       Honeybees are resilient to change

Honeybee colonies live throughout the winter, survive for several years and the tens of thousands of worker bees in the nest buffers their colonies against hardship. If conditions are poor one year, they can bounce back over the following one so long as they have a fertile queen to ensure the next generation. Moreover they can search for food over many miles if flowers are in locally short supply. 
 By contrast, all wild bees have annual life cycles. Each year is a new generation and a new nest.  They also have less insurance against hardship. Bumblebee nests have only a few hundred, or even tens of workers to support the colony and most solitary bees act as single mothers with the female taking sole responsibility for building the nest and providing for her offspring. If they have a bad year, numbers drastically decline.

Solitary bees are particularly sensitive, since they usually have short adult lifespans, fly only a few hundred meters from the nest and often rely on specific flower types, even down to a single plant species.  If a wildflower meadow is so much as cut or grazed at the wrong time of year, entire populations can be lost. Our endangered bumblebees also rely on certain flowers, mainly legumes (plants in the pea family) such as clover which provide protein-rich pollen for their larvae, alongside other perennial plants which need sensitive management. Honeybees do need a variety of flowers to support them throughout the year, but they have no such specialisms.

In addition, solitary bees and bumblebees usually have no help whatsoever in their struggle for survival, but most UK honeybees enjoy all the luxuries of domestication. Beekeepers build their hives, supplement their diet with sugar syrup and treat their ills. In some cases, their colonies are moved to pastures new to pollinate flowering crops, ensuring a ready food supply, whilst wild bees are left to eke a living on the sparse wildflowers at the field edges. This is the most important distinction between the honeybee and its wild cousins. 



Left: The majority of UK honeybee colonies are tended by Beekeepers in Hives (Image by Migco-wikimedia commons). Right: Other bees are not hive dwellers. Many solitary bees (here a Lasioglossum sp.) dig nest holes in the ground, which they construct and tend all on their own (Photo © by author).

Of course, beekeepers have their fingers on the pulse when it comes to flower provisions in the landscape and the common challenges their colonies are facing with wild bees, but honeybee numbers are partly dependent on the human efforts of their beekeepers, not just the state of the environment. We must look to conserving habitats for our wild bees.


3.       Honeybees are not super-pollinators


Honeybees are undoubtedly hard-working pollinators, since they must visit around two million flowers for each pound of honey5, but they are not the sole providers of our crops as is often implied. Several research projects have attempted to find out exactly how much different pollinators contribute to our food supply and the ecosystem. A Global study found that around 2% of bee species pollinate 80% of world crops and wild bees contribute just as much as honeybees to crop pollination6(Still an impressive effort from the honeybees!). Other studies have shown that when it comes to bearing fruit, honeybees are no substitute for our wild pollinators7. The wild Red mason bee for example is 120 times more efficient on apple blossoms than the honeybee8, and on strawberries, a combination of bee species feeding from different parts of the composite flowers creates larger, better-formed and tastier fruit9!
In terms of wild flowers, a study found honeybees lag far behind their wild cousins, visiting less than 5% of flowers in an ancient haymeadow, compared to over 30% visited by wild bees which were the top pollinators10.

This has more important implications than deriding honeybees.  It shows that we must preserve our wildflower-rich habitats to support our wild pollinator diversity if we want our fields and orchards to be fruitful.

So why are these other species so much better at pollinating? The reasons are twofold.
 Firstly, though the honeybee has many amazing adaptations for its lifestyle and visits at least 75 crop types worldwide, it simply doesn’t have the kit to deal with every flower type. Many flower shapes are adapted for specific pollinators to help ensure their pollen isn’t wasted on unrelated plants.
Take the bumblebees. They have the unique ability to “buzz pollinate”, vibrating their bodies using their wing muscles to release pollen, a technique essential for the tightly-clasped stamens of the tomato family and poppies (Every tomato, pepper and chilli you’ve eaten is pollinated by bumblebees).  Long-tongued bumblebees triumph on deep flowers such as Foxgloves with nectaries unreachable to other species.

But the honeybee does put its tools to good use. Perhaps too good! This is the second issue. The relationship between plants and pollinators is not as cosy as you might think. Bees are excellent pollen-collectors, but they have a vested interest to return it to the nest as food rather than transfer it between plants.  Since it has to provide for thousands of hungry larvae and other workers, the honeybee has become the peak of pollen-gathering efficiency. It gathers pollen into ‘baskets’ on its legs, stuck together with nectar and saliva, carrying little wastage on its nearly hairless abdomen. This leaves little loose pollen to drop onto and fertilise the next flower.
By contrast, solitary bees (Such as the Red mason bee) are rather messier since they only need enough pollen to stock one nest cell at a time. Instead of a basket of bristles, solitary bees have legs and/or abdomens coated in shaggy, branched hairs like a brush. The grains are not stuck together so easily drop off onto the next flower, leading to more efficient pollination.


The Honeybee (Left) is an efficient pollen-gatherer, packing it neatly into ‘baskets’ stuck to its legs. This Early mining bee (Andrena haemorrhoa) (Right) is a more efficient pollinator, brushing pollen loosely onto its hairy legs, from which it more easily drops off onto other flowers and fertilises them. Photos by ©Lamia textor (agrilus.blogspot.co.uk)


To wrap things up..


This article isn’t intended to demean the honeybee or beekeepers, rather it is to put the honeybee in context with its relatives and other pollinators. The honeybee is an amazing and incredible insect in its own right. Beekeepers share this fascination .Their knowledge, dedication and observation can tell us a great deal about the state of our pollinators and contribute to the passionate support our bees so desperately need. My father is a beekeeper and the fascinating honeybee contributed greatly to my appreciation of insects.

The take home lesson is that we shouldn’t solely idolise the honeybee. It is neither the ‘best’ pollinator nor the most reliable indicator of our environment. The honeybee shares its pollinator pedestal with a great variety of other species equally deserving of our appreciation if not more so and we need to conserve our flower-rich habitats to support this variety. It is important that we diversity of bee species and their needs, and act to protect the environment on which they depend in ways that help them,  rather than fixating on the hive dwelling honeybee, both for the sake of bees and our food supply.

Think bees, not bee.


Want to explore the diversity of Britain’s bees? Visit the Bees, Wasps and Ants Recording Society (BWARS) and Steven Falk’s Flickr collection.

Learn more about bees and how to help them with Buglife the Bumblebee conservation Trust and Hymettus. You can help to understand the state of Britain’s bumblebees by becoming a Beewalker , and help bees and other pollinators in your garden by making a Pollinator Pledge.


References

1-Buglife. (2014) Get Britain Buzzing: A Manifesto for Pollinators. https://www.buglife.org.uk/sites/default/files/Pollinator%20manifesto%20with%20covers_1.pdf

2- Breeze,T.D. et al (2012) The Decline of England’s Bees: Policy Review and Recommendations http://www.foe.co.uk/sites/default/files/downloads/beesreport.pdf

3-JNCC. (2007) UK BAP priority terrestrial invertebrate species. http://jncc.defra.gov.uk/page-5169#insects

4-DEFRA. (2014) The National Pollinator Strategy: for bees and other pollinators in England. https://www.gov.uk/government/uploads/system/uploads/attachment_data/file/409431/pb14221-national-pollinators-strategy.pdf

5- National Honey Board. Honey Trivia .http://www.honey.com/newsroom/press-kits/honey-trivia

6- Kleijn,D et al. (2015) Delivery of crop pollination services is an insufficient argument for wild pollinator conservation. Nature Communications, 6. http://www.nature.com/ncomms/2015/150616/ncomms8414/full/ncomms8414.html

7-Garibaldi,L.A. et al. (2013) Wild Pollinators Enhance Fruit Set of Crops Regardless of Honey Bee Abundance. Science, 339 (6127) 1608-1611. http://www.sciencemag.org/content/339/6127/1608.abstract

8-AHDB Horticulture. Apple Best Practice Guide. http://apples.hdc.org.uk/agronomy-pollination-additional-information.asp


9-Chagnon,M. et al. (1993) Complementary Aspects of Strawberry Pollination by Honey and Indigenous Bees (Hymenoptera). Journal of Economic Entomology, 86(2)416-420.
http://jee.oxfordjournals.org/content/86/2/416



10- Dicks,L.V. et al. (2002) Compartmentalization in plant–insect flower visitor webs. Journal of Animal Ecology 71, 32-43 http://onlinelibrary.wiley.com/doi/10.1046/j.0021-8790.2001.00572.x/full









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