Bee Pollination

Updated: 22nd February 2021

Around a third of the food we eat is estimated to be dependent on insect and bee pollination.  In providing this pollination service, bees literally contribute billions in cash to the world economy. This article is about the cash value contribution of bees to pollination services, and the importance of different types of bees species (e.g. leafcutter bees, mason bees, honey bees and bumble bees) to pollination and the food chain.

How Much Is Bee Pollination Worth To The Global Economy?

common carder bumble bee in mid flight, flying toward raspberry flowers

In October 2010, the United Nations published a report, in which they place a value on insect pollination at £134 billion (153bn Euros).  The reason for putting a financial value on things are understandable, though I think it's an exceedingly narrow means of measuring real value. Basically, it misses the point that biodiversity is priceless, but nevertheless, here are some financial values in different currencies (although estimations vary):

US $:  $40 billion per annum

Canada: C$1.2 billion per annum

European Union (EU): Euros 5 billion per annum (1989 figures)

Australia: Aus$156 million per annum

Source: cited in Bumblebee Behaviour and Ecology, by Professor Dave Goulson, 2003.

Which food crops do bees pollinate?

gingery-colored carder bumble bee foraging on a pale pink apple blossom flowersA carder bumble bee foraging on an apple blossom flower. As she does so, she will enable pollination to occur by carrying pollen grains on her furry body from the male (stamen) to the female (carpel) parts of flowers, ultimately resulting in fruit (apples) on the tree.

Many different food crops are pollinated by bees, along with other insect pollinators.  The list includes:

  • various vegetables from the pea and bean family
  • squashes, curcubits, corgettes
  • a variety of nuts such as almonds (for which the honey bee is especially important)
  • berry fruits, for example, blueberries to cranberries, strawberries, raspberries and blackberries  and more
  • stone fruits, such as cherries, plums, apricots
  • fruits with pips, such as apples and pears
  • food crops eaten by livestock, such as alfalfa.

Many plants are pollinated by bees and other insects, which in turn create foods for other creatures in the form of seeds, hips, nuts and berries, as well as the plant itself. Chestnuts, for example, are enjoyed by deer; holly berries are snaffled hungrily by birds in winter - these fruits are borne on trees that first have their flowers pollinated by insects like bees.

How do bees pollinate flowers?

Bees pollinate flowers by carrying pollen on their bodies from the male part (the ‘stamen’) of one flower to the female part (the ‘carpel’) of another flower.

Read more about the  plant pollination process. 

Which bees pollinate the most flowers?

All bee species are potential pollinators, although some are likely to be broadly more efficient than others, whilst some will be specialists, and as such may be crucial to the survival of the plant on which it specializes. 

Currently, honey bees are mostly used in crop pollination and they are vital for some food crops, such as almonds.  This is because they are able to venture out in cooler temperatures when almond flowers need to be pollinated.  However, many wild bees of different species are increasingly being recognized for their value as pollinations.  It's unlikely that all wild bee species are equally valuable in terms of their pollination service.  It's worth remembering that the 'bee' group of insects includes species such as the waspy-looking cleptoparasite Nomad species pictured below.  Whilst they may provide some service, it is difficult to imagine they would be on a par with the bumble bee, honey bee, or solitary species such as leafcutters and mason bees.

black and yellow nomad bee perched on a yellow flowerAbove - a nomad bee species

It is impossible to calculate which bees pollinate the most flowers overall (including wild and garden flowers, trees, hedgerows and shrubs), because it relies on many factors, such as the presence of wild species and the suitability of local habitat.  Likewise, the availability of honey bees will rely on the presence of wild colonies, or, for example, the involvement of commercial colonies (colonies hired out by beekeepers to farmers wanting to purchase crop pollination services).

Why are honey bees mostly used for pollination in commercial crop growing?

honey bee worker with full pollen baskets on a yellow dandelion flower

Primarily, honey bees have been used in crop pollination, because humans have been keeping bees for many years.  This has meant it is possible to transport colonies from one location to another.

However, increasingly, ways are being found to harness  pollination from other bees species:

The Megachilidae Family

leafcutter bee visiting a purple geranium flowerLeafcutter bees are very efficient pollinators of flowers and foods.

These types of bees are extremely efficient pollinators. This family includes mason bees and leafcutter bees. Some are used in commercial pollination, such as Alfalfa leafcutter bees (Megachile rotundata), and Osmia lignaria (the "Orchard Mason Bee" or "Blue Orchard Bee"), which is especially sold for use in orchard crop pollination.

According to the U. S. Department of Agriculture researchers, only 250 female blue orchard bees (Osmia lignaria) are required to pollinate an acre of apples - a service equivalent to one or two honey bees hives, each containing 15,000 to 20,000 workers (Bosch and Kemp, 2001).

It's possible to farm in harmony with nature, attract these bees to the land, which is better for crop yields.

Bumble Bees

bumble bee flying toward a blueberry flowerBumble bees love foraging on blueberries. They simultaneously pollinate the flowers which ensures the bush produces more fruits.

Bumble bees are also used for commercial pollination of crops, although farmers can attract them naturally to their land by using wildlife friendly farming techniques, such as allowing areas of meadow, maintaining pollinator margins and so on.

Some plants require ‘buzz pollination’ – this is especially important for crops such as tomatoes.

Additionally, different types of bumble bees have different tongue lengths, and so bumble bees as a whole will tackle a wide variety of plants.  Read more about bumble bee pollination.