Pollination is of paramount importance for the world agricultural production.
The service provided by pollinators is of $153 billion US Dollars, equivalent to 9.5% of the value of the total world food production.
If they are wild or domestic, bees are the major players in this essential activity for the quality and performance of agricultural production. For information, in 2009 the value of pollination of honeybees was estimated at $11.68 billion US Dollars in the United States, and that of wild pollinators at $3.44 billion US Dollars.
In order to accurately assess the dependence of pollinators of the world agricultural production used directly by humans for food, in 2006 a group of researchers from Germany, France (INRA Avignon), Australia and the United States analyzed the results of scientific work on the 115 most important crops for more than 200 countries worldwide.
Based on these studies, the production of over three quarters of crops benefit from the pollination activity of animals: most fruit crops, vegetables, oil and protein, nuts, spices and stimulants (coffee, cocoa)... in terms of weight, this represents 35% of global food production: a bite out of three on average!
This difference between the many species that depend on bees for pollination and their relatively lower weight in the production of food comes only from the fact that grains such as wheat, corn and rice, which accounts for almost 60% of food consumed in the world, hardly depend on pollinators for reproduction. (The remaining 5% are from crops for which the impact of pollinators has not been studied yet).
That is reassuring. This means that if bees disappeared, we would theoretically not starve overnight. However, the variety and quality of our food would fall instantly and quite dramatically for the world population.
Without foragers, most crops do not reach a satisfactory production. This is the case for:
Many wildlife species: rosemary, thyme, lavender, mustard …
Almost all fruit trees: apple, pear, apricot, almond, peach, cherry, etc.
Major oilseeds, rapeseed and sunflower, and protein,
Almost all vegetable crops: zucchini, pumpkins, tomatoes, lettuce,
Strawberries, raspberries and everything else ...
Seeds of cruciferous: radish, cabbage, turnips ...
Umbelliferae: carrots, celery, parsley ...
alliaceae: onions, leeks …
Hard to imagine any of our meals for which bees are not associated closely!
"The way humanity manages its natural assets, including those related to pollinator populations, will in part define our collective future in the 21st century. The fact is that of the 100 crop species that provide 90% of food production worldwide over 70 are pollinated by bees. In the 21st century, human beings have fabricated the illusion that they could be independent of nature through technological prowess. The case of the bees reminds us to reality with nearly seven billion people on earth, we are rather more dependent on services provided by nature." Achim Steiner, Under-Secretary-General of the United Nations and Executive Director of UNEP
How could bees acquire such importance in biodiversity that their disappearance would make fear scientists a real quiet cataclysm: the questioning of the entire food chain as we know it today?
To understand we need to look a little on the history of evolution, and the quite exceptional characters that bees have acquired during their joint history with flowering plants.
A long love story between insects and plants
This is one of the greatest achievements of evolution.
Flowering plants and insects are released both winners in their respective categories: those of plants and animals.
Flowering plants first:
They appeared last in the evolution of the plant world about 130 million years ago (compared with the appearance of the first land plants more than 500 million years ago!). They account for slightly more than two thirds of today’s plant species, with 250 to 300,000 species over the entire earth surface.
The sex life of flowers, initially entrusted exclusively to the wind, responsible for propelling huge masses of pollen in the atmosphere, in a risky journey and most of the time unsuccessful, proved to be a not very profitable adventure in the end.
Significant progress was recorded when the insects discovered that pollen was a source of food for them and ate simply capsules stamens containing the pollen.
When consuming series of stamens of flowers nearby, the transport of sufficient quantities of the pollen took place on the female receptacles of other flowers. And reproduction was somehow guaranteed. Some insects such as rose chafers behave still today in such a brutal manner with flowers.
A transfer of very mobile pollen grains from flower to flower characterizes a delicate behavior with flowers, which is ideal from the point of view of the flowers.
Among the phytophagous (herbivorous), the butterflies were the first engaged in this kind of couple's relationship, which is so special with flowers. A relationship cemented by small reciprocal arrangements. Scientists call this co-evolution: insects and flowers evolving together, adapting to each other over a long history. The proboscis of butterflies and the nectaries at the bottom of tubular flowers bear witness to this common journey.
But it is in bees that flowers have found peerless partners. They carried with them at the heart of a long co-evolution, such a game of back and forth that they reconciled as much as possible the behavior of an ideal couple.
Bees and bumblebees have developed from a genuine tacit mutual agreement: "Pollen and nectar for my offspring, and in return, I unwittingly carry pollen to other flowers." This lasts for 100 million years: we see, again, a common evolutionary history. It concerns the position of the nectaries, the morphology of flowers and the mouthparts of insects.
Pollination by insects is the source of a very large part of today’s observed biodiversity. The extraordinary success of flowering plants blew the diversity of insect species that feed on plants. And these are the bees, and the large family of hymenoptera which they are part of who benefited the most of it.
That's why today, if these pollinators disappeared, 80% of species of flowering plants and 84% of the cultivated species would disappear with them.
Bees are not the only insects to pollinate the flowers: flies, butterflies, beetles, and a bunch of other flying insects related to bees, like wasps, bumblebees and even ants can act as pollinator.
But no other insect is as active and effective as bees that make honey - what scientists call "Apis mellifera".
In fact in this area, no other insect comes near the abilities of bees.
On the planet, about 80% of flowering plants are pollinated by insects and among them about 85% are pollinated by bees. For fruit trees even 90% of species are visited and pollinated by bees.
It is estimated that bees are able to forage 170,000 species of different flowering plants - a global record! And nearly 40,000 species of flowering plants depend on bees directly and would be in poor health without their annual visit.
And hold on tight: this ocean of flowers is foraged by only nine species of honeybees. Only one species pollinates whole of Africa; only one other species pollinates whole of Europe. This is something quite unique: a single species that has adapted to all climates and all European environments, and today plays a vital role for most of our flowers, our fruits and vegetables, our crops, our hedges, our trees and our forests...!
This kind of monopoly, developed at such a scale is rare in the history of evolution.
This huge disproportion between the client plants and the "pollination service providers" makes us think that the bees and their so special form of community life are so powerful that they leave their competitors little living space to coexist...
A bee colony has something to shake all competitors with the zeal to work it deploys:
In one day, a single colony of bees can visit millions of flowers. It's amazing but true: in top form, a bee can visit up to 3,000 flowers per day, and a nice colony of bees can accommodate from 30 to 40,000 individuals. Do the math: even assuming that in this colony only 2,000 bees will forage during a day it's still six million flowers visited and fertilized in the day!
Several reasons for this: "The morphology of bees (presence of branched hairs all over the body), their diet consists exclusively of nectar and pollen, and their foraging behavior (loyalty to a plant species on a trip), make them particularly effective and accurate pollen vectors. "(B.Vaissière, N.Morison, G.Carré, 2005)
Bees carry commonly tens of thousands of pollen grains on their bodies and they deposit large quantities of them on the stigmas of the flowers they visit.
Bees transmit the coordinates of all new flowers locations.
This is what allows them to visit almost all flowers as soon as they bloom. Virtually no flower escapes their vigilance. And as bees take advantage of all types of flowers, all flowers have the same opportunities to be sought by bees.
Result: The number of flowers pollinated, the rapid mobilization of the appropriate number of foraging bees inside the colony, the enormous adaptability of each worker and the entire colony to the "Floral situation" encountered in the fields, make bees the ideal partner for flowering plants.
Scientists have searched in vain, there is no alternative to replace the colossal work bees do every year.
We can use other breeding insects to pollinate farm crops, as using bumblebees for tomatoes grown in greenhouses. But it does not work in open fields. And bumblebees also know the same difficulties as bees, which they are very close to.
We can pollinate crops by hand, as is done already for small crops such as vanilla for example. But it is a technique that is far too expensive to be extended to field crops, and that would place salad, potatoes and tomatoes at the same level as caviar.
We could increase pollination technically by the wind. Several companies have already tried worldwide, with helicopters, or with machines shaking plants ... But no method has ever produced meaningful results.
(Remember: 70 to 80 million years of common evolution between flowers and bees to reach this highly sophisticated system of pollination that everyone enjoys free today!)
Some crops can produce fruits without fertilization or spontaneously – it is the case for bananas, for example - or because of the spraying of specific hormones. But these techniques are far from being applicable to all species, and the impacts on the taste quality of the fruit are sometimes catastrophic.
Today we speak to try to make bee drones that could provide the same services that our dear foragers. If we did, it would certainly be a lucrative business, as the needs seem endless.
Because bees do not only serve to ensure our food needs. They also pollinate wildflowers, shrubs and hedges, trees and forests, and in this way contribute to the survival of hundreds of thousands of plant species.
Not to mention the animals, insects, birds and mammals that depend directly on it.