The importance of bees in agriculture
How do bees help food production?
Albert Einstein allegedly said that, “If the bee disappeared off the face of the Earth, man would only have four years left to live.” Doom-laden words indeed, even if Einstein himself never actually said it. So why would the demise of the humble bee bring about ecological Armageddon?
Pollination is vital to life on our planet. Bees and other pollinators have thrived for millions of years, maintaining biodiversity and vibrant ecosystems for plants, humans and the bees themselves. Pollinators are essential to the production of fruits, vegetables, oils, nuts and seeds that we eat every day. Pollinators affect 35 percent of global agricultural land, supporting the production of 87 of the leading food crops worldwide. Furthermore, pollination-dependent crops are five times more valuable than those that do not need pollination. The price tag of global crops directly relying on pollinators is estimated to be between US$235 and US$577 billion a year.
In the UK alone, the services of bees and other pollinators are worth £691m a year, in terms of the value of the crops they pollinate. Without bees, it would cost UK farmers £1.8 billion a year to pollinate their crops.
There are around 20,000 described bee species worldwide. Most of these bees are known as solitary bees with only 250 bumblebee species, 9 honey bee species and a number of social stingless bees worldwide. The UK is home to 25 species of bumble bee, 224 species of solitary bee and 1 honey bee species. However, the UK has already lost around 13 species since 1900 and another 35 are currently at risk of extinction.
Why are bees declining?
A recent study, carried out by the Centre for Ecology and Hydrology (CEH) in Oxfordshire, looked at trends in 353 wild bees and hoverflies in Scotland, England and Wales over 33 years from 1980. Scientists found that losses were concentrated among the rarer, specialised species. Although this is good news for the more common pollinators, it means that biodiversity is weakened.
This has an enormous impact on agriculture as many farmers rely on a diversity of bees to pollinate their produce. For example, British commercial apple growers benefit from the free pollination services of the Red Mason Bee. This species can be 120 times more efficient at pollinating apple blossoms than honeybees.
Land use changes are one of the main causes of biodiversity loss, including of pollinator species. Urbanised areas and intensively managed agricultural land have reduced floral diversity and nesting habitat for pollinators compared to natural habitats. Since the Second World War, the UK has lost 97% of its wildflower meadows, a vital habitat which pollinators depend on for food and shelter.
Parasites and disease, particularly the parasitic Varroa mite and the viruses it transmits, have been identified as a particular threat to honey bees. Varroa mites and viral diseases are known to affect the efficiency of crop pollination by honey bees through the elimination of colonies. Colonies infested with Varroa mites become less efficient pollinators, because they deposit fewer pollen grains on the flower stigma.
Insecticides, particularly neonicotinoids, have been implicated in the decline of both domestic and wild bee species. Neonicotinoid pesticides protect crops against pests such as aphids by blocking receptors in the insects’ brains, paralyzing and killing them. In small doses, the pesticides aren’t lethal to bees, but they can wreak havoc on bees’ abilities to navigate, find food, reproduce, and form new colonies.
What is being done to halt the decline in bees?
In November 2014 the government introduced a National Pollinator Strategy which set out a 10-year plan for “taking action to improve the state of our bees and other pollinating insects and to build up our understanding of current populations and of the causes of decline”. Many of the Strategy’s actions are about working with farmers and the public to expand food, shelter and nest sites across types of land (the key requirements for bee colonies) as well as new research and monitoring to fill gaps in knowledge.
Farmers and growers across pastoral, mixed and arable farmland are well placed to improve the quality and amount of diverse and flower-rich habitats for pollinators. The Government works with farmers to improve the environmental management of farmland, balancing this with the need to promote competition and protect food security. They are supported by emerging evidence that providing habitat through agri-environment schemes (e.g. buffer strips, pollen and nectar mixtures, wild bird seed mixtures, hay meadows and wild flower areas) does attract pollinators.
Since December 2013, the EU has restricted the use of three neonicotinoids, Clothianidin, Imidacloprid and Thiamethoxam, on a number of crops attractive to bees, such as oilseed rape. In November 2017, the UK Government announced its support of European Commission proposals to extend these restrictions after advice from the Expert Committee on Pesticides.
On a smaller scale, charities such as Friends of The Earth and the Bumblebee Conservation Trust are encouraging people to plant bee-friendly gardens. Such plants include lavender, hawthorn, honeysuckle and even snowdrops which can provide much-needed pollen for bees emerging on sunny winter days.
According to bee expert, Professor Dave Goulson, “Imagine if every garden, park and school grounds had bee-friendly flowers, and we grew wild flowers on our roundabouts and road verges; our towns and cities could become huge nature reserves for pollinators”.
