A brief guide to bees
This is a simple summary of the differences between the three main groups of bees, and their varying requirements. Bees are fascinating insects and we may develop a greater interest in them as we look into their individual足needs. What are their key requirements and can we, within profitable agriculture, make better provision for them?
Of the 3 types of bee, there are 26 bumblebee species, 1 honeybee species, and more than 200 solitary bee species. Honeybees
The honeybee is the only species that makes honey as a food source. Honey is produced to see the colony through the winter, and is made from nectar, which is essentially a sugar solution. Nectar provides energy, so is used as fuel for flying and sustaining the adults. Pollen, which is protein, feeds the queen and the young. Honeybees live in a colony which is about fifteen thousand strong. The queen is the dominant bee and her role is mainly to lay eggs. The other bees in the colony comprise workers, which are unfertilised females which provide the colony with all its needs, and males, which mate with females to produce new queens. An important difference between honeybees and the other two types of bee is that honeybee colonies continue an unbroken cycle from year to year, with new queens replacing old queens or setting up new colonies. Honeybees are farmed, as they can live very successfully in man-made hives which act as movable homes, whilst making honey which is a valuable crop.
There are many species of bumblebee, only six of which are common in the UK. All are generally larger, rounder and hairier than either honey or solitary bees. They do not make honey, but store a small amount of nectar which acts as an emergency food supply. As only the new queens overwinter, bumblebees have no need for honey as a food store. Bumblebees live in much smaller
colonies, from 50 to 250 depending on the species. The colonies are made up of a queen, unmated female workers, and males which mate with females to produce new queens. These new queens hibernate through the winter and emerge in the spring to begin new colonies. Only the new queens survive the winter; all other bees from the old colonies die in the autumn. Bumblebees are active from about March to September depending on the species.
The many species of solitary bee vary in size, but are usually smaller and a little hairier than honeybees. They can sometimes be difficult to separate from honeybees, but the female solitaries carry dry pollen on their rear legs or under their abdomen, whilst honeybees carry a ball of wetted pollen. Solitary bees do not live in colonies, but can often be found living close to each other in a patch of good habitat. This group of bees can be split into mining bees (which make holes in the ground or sometimes walls), and leaf cutter and mason bees. These last two use leaves and mud respectively, to make their nests. In all cases the female makes the nest, lays the eggs and collects the pollen, placing the pollen alongside the egg before sealing the nest chamber. Solitary bees can be seen between March and August. Some solitaries have two generations a year, April and July, but most only have one.
What do bees need?
The six-week life of a bee
All female bees (except queens) live for about six weeks. Honeybees – become active when the weather warms up in mid-March. Once a nest has been established, the queen produces a continuous supply of female workers till late autumn, each with an approximate six-week life span. Food is provided by flowers orstored honey. In the autumn the colony and any newlyformed colonies overwinter ready for the next year.
All bees need nest sites where food can be found within foraging range. Honeybees can forage effectively up to 2 km, bumblebees up to 1.5 km and solitary bees 500 m–1 km depending on their size.
Food is pollen which is mainly protein, used by females to develop ovaries and feed young; and nectar, which is basically sugar solution, used to provide energy (flying fuel!). All bees need the right food at the right time, so depend on a range of flowers from March to September. There are fewer flowers between March and May compared with June to August, so the bees that live their lives between March and May are more likely to experience a critical ‘hungry gap’.
Honeybees use man-made hives, but feral bees can use trees, chimneys or other similar dark cavities.
Bumblebees can be split into two groups. Those which nest above ground are called ‘carders’ such as Bombus pascuorum, B. ruderarius, B. muscorum, B. humilis and B. sylvarum. The other species nest below ground. The belowground nesters use small mammal holes, generally found in tall tussocky grass in warm sunny locations, whilst the carders use a more open tussocky grass structure where light and warmth can penetrate. Solitary bee nest sites are many and varied, but are generally in full sun on bare ground or in very short, gappy grass.
Bumblebees – also become active when the weather warms up in about mid-March. At this time, new queens emerge from hibernation and begin new colonies by producing female workers, each also with about a six-week life span. Males are produced in late summer, and these mate with new queens which then go into hibernation. The old queen, and all workers and males, die in the autumn. The new queen emerges from hibernation the following spring to begin the cycle again. Food is needed from March to September and has to come from a succession of available flowers.
Unlike honeybees, bumblebees have no stored food (honey); this means that each year the ‘hungry gap’ for bumblebees constitutes a real hazard which farmers can help to overcome. Solitary bees – The earliest of the solitary bee males hatch in mid-March just before the females (there are no queens), and mate with the females as they emerge. They then die, leaving the fertilised females around six weeks to find a nest, lay eggs and provide food for the egg when it hatches, before themselves dying. If food is limiting in March and April (the early solitaries’ ‘hungry gap’) a whole year’s generation will fail because there is no colony to support the single female (hence ‘solitary bee’). Later flowers/food may rescue the season-long honey and bumblebee colonies so continuity can be maintained. This luxury of later food is of no use to a female solitary living her six-week life in early spring.
“The hungry gap is a real hazard that farmers can help alleviate by sowing the right flowers” Marek Nowakowski, The Wildlife Farming Company
Farmers and Syngenta – working together The Syngenta initiative Operation Bumblebee 2005-2008 trained over 700 farmers who collectively sowed 1,200 hectares of pollen and nectar. At the end of the project this sown area was approximately 50% of the total pollen and nectar in the Entry Level Scheme. The rapid recovery of the once rare Bombus ruderatus is attributed to Operation Bumblebee sowing areas containing red clover.
Pollination or honey? • 1990 – 2000 15 x 10 km2
Change in distribution of Bombus ruderatus
The honeybee is the only species which makes honey.
• 2000 – 2009 64 x 10 km2
However, all use pollen – with one big difference: wet or dry? Honeybees and bumblebees collect pollen, moisten it, roll it into a ball and stick it to special hairs on their hind legs, forming pollen baskets. Recent work shows that this wet pollen could be as low as 20% viable, so is of limited use in pollination. In contrast, solitary bees carry dry pollen on their hind legs or abdomens. Dry pollen can be around 80% viable, so solitary bees provide a vastly more effective pollination service. So why are honeybees and bumblebees used in pollination? Honeybees are readily available and ‘farmed’ by many beekeepers, so have a place in pollination. Bumblebees can also be farmed, with colonies available for specialist crop pollination. Solitary bees are far more demanding and as yet have never been ‘farmed’, but Syngenta, together with a group of specialists, are developing the habitat delivery skills to provide these natural pollinators with greater opportunities. This will enable farmers to encourage more natural pollinators on their farms.
How do you get involved? For more information on Operation Pollinator and details of how you can get involved, visit: www.operationpollinator.com
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