The Honest Truth

Bumblebees are an essential part of life on earth, but . . .

The males are only interested in drink and sex

IT’S May, the time of year when gardens begin to hum with activity in preparation for the height of the growing season.
But it’s not just the humans venturing out for the first time, bees are hard at work doing their vital job of pollinating the flowers that make gardens bloom.
This year, however, there may be fewer bees than usual. Numbers have taken an alarming dip in recent years — and that could be bad news for us humans.
It’s been claimed that without bees to pollinate crops the human race would die out within months. 
That’s the scenario in this summer’s blockbuster, The Happening.
The Stirling-based Bumblebee Conservation Trust is asking folk to report bee sightings so they can build a picture of how bumblebees are coping with the threats they face.
Dr Ben Darvill (right), from Dunblane, is director of the BCT. He told James Millar The Honest Truth about bumblebees.

HOW MANY are there?

There were 24 native UK species, 18 true bumblebees and six cuckoo bumblebees that take over other nests. There’s a “big six” of types that are found nationwide, the rest are restricted to different areas of the country.

There’s no way of knowing how many there are in the UK, what’s crucial is the number of nests. Finding them is extremely hard —they’re frequently underground and the only evidence might be a bee visiting every five minutes. 

However, badgers can find and dig up nests so we figured there must be a smell they give off. 

We took a chance on training a dog to find them and straight away it found one belonging to a very rare species. We now have two springer spaniels, trained by the Ministry of Defence, that are very effective. 

ARE THEY all yellow and black?

No. For example the red tailed bumblebee is black with a red tail. The white tailed bumblebee is black and yellow with a white tail.

They do all look similar though — it’s an advantage to look the same so predators know to avoid them.

HOW DO they live?

They have an annual cycle. The queen bee is the only one to survive the winter, she hibernates in a hole in the ground. In spring she starts a nest — not a hive like a honey bee — probably in a rodent burrow. Then she makes a little pot and fills it with honey. She lays her eggs then sits on them vibrating her wings for six weeks and sipping from the honey for energy. 

When the eggs hatch she collects pollen to feed the larvae. They grow into female worker bees who then forage for pollen to feed the next batch of larvae and so make the colony larger. Once the population is a certain size the queen will feed up some of the females, which switches on their reproductive system and makes them queens. 

The queen will also produce some males. She won’t have done that before because males are only interested in drink and sex, so aren’t much use to the colony — but are obviously needed to fertilise the new generation of queens who will survive the winter and start the cycle again the following year.

HOW LONG do they live?

A queen lives for a year. Workers live a few weeks. 

DIFFERENCE BETWEEN bumblebees and honey bees?

They’re closely related and rely on the same flowers to survive. Bumblebees only last one season while honey bees live throughout the year, the queen and a select group of crack workers will work through the winter. Honey bees have been bred selectively to make masses of honey. Bumblebees produce a very small amount. You’d have to destroy an entire colony just to have enough for breakfast.

Bumblebees are definitely native to Britain, honey bees may have been introduced, no-one is sure.

Bumblebees pollinate a greater range of plants whatever the weather. They do something called sonicating, a special frequency of buzz that triggers the release of pollen in plants such as tomatoes.

In Australia there are no bumblebees but they grow a lot of tomatoes so humans have to go round the tomato plants with vibrating implements to get the plants to release pollen.

WHY ARE bumblebees so important?

Their pollination services both wildflowers and agriculture. I’ve seen estimates that their work is worth £200 million to £400million per year. Without bumblebees the seed sets of agricultural crops would be reduced, meaning less and more expensive food. If wildflowers aren’t pollinated we’d lose the colour from our countryside but also other species who rely on those flowers.

Einstein is supposed to have said that without bumblebees humans would quickly die out, but then he was a nuclear physicist not a biologist. If bumblebees disappeared we probably have the technology to cope these days — but vast numbers of species of animals and crops would also die.

WHY ARE they threatened?

In the last 100 years they’ve lost 98 per cent of their flower-rich habitat. Particularly after World War 2 farmers were encouraged to increase productivity by bringing unimproved grasslands into use. Also there’s been much more use of herbicides and pesticides. 

Now there are huge areas of the countryside that are just crops and hedgerows, no wildflowers for bumblebees.

Climate change is going to affect bumblebees but loss of habitat is a far bigger threat. 

There’s no evidence that, as has been reported, it has anything to do with mobile phones or Wi-Fi.

WHAT’S THE scale of the threat?

Of the 18 true species we’ve already lost three and another six are listed on the UK Biodiversity Action Plan as under threat.

WHAT CAN ordinary folk do to help?

A lot. Gardens account for over one million hectares, more than all the nature reserves in the UK combined. Plant the right sort of plants — traditional cottage garden plants like foxgloves, poppies and lavender. There’s a long list on the BCT website. Farmers and crofters can help by taking up financial incentives to manage their land in an environmentally friendly way. There’s an affection for bumblebees and many farmers are willing to help but don’t know how. We’re happy to offer advice.

IS IT true bees defy the laws of physics to fly?

People thought they did because they have large bodies but relatively small wings. We now understand that they make use of vortex forces — achieving extra lift from the swirling wind they create by moving their wings in a circular motion rather than just up and down.

DO THEY sting?

They can, but unlike a wasp or a honeybee they won’t unless severely provoked or you interfere with the nest in a major way. I’ve been working with them for eight years and have never been stung.

WHERE DOES the name come from?

They used to be called humble bees, I’m not sure if that just transformed into bumblebees. They have lots of other names. In some parts of Scotland they are foggy bummers, I think that’s where the word fogey, as in old fogey came from.

In the west country they are sometimes called dumbledors. I believe that’s where JK Rowling got the name for the headmaster in the Harry Potter books. She said she imagined him humming as he strode round Hogwarts School.

WHAT WOULD surprise us about bumblebees?

They have smelly feet. It makes no sense for a bee to visit a plant that’s already been visited by another bee so before landing they will sniff out a flower with their antennae, if they smell cheesy feet then they’ll move on.

WHAT’S THE Bumblebee Conservation Trust?

Professor Dave Goulson and I launched it in May 2006. We already have more than 2000 members. Our work is mainly education and conservation. We have a pack for children in primary 2 or 3 that teachers can get for free by contacting us. We also work with landowners telling them how they can help.

We based the Trust at the University of Stirling because we do our research there. It has turned out to be a good location because it is so central and because Scotland contains more rare and threatened species of bumblebee than the rest of the UK.

HOW DID you become interested in bumblebees?

I’ve always had a passion for wildlife and I increasingly became aware of how incredibly important bumblebees are. There’s a great affection for them, the sound of a summer’s day is a bumblebee buzzing by. What better way is there to spend your time than trying to conserve that?

© All copyright D.C. Thomson & Co. Ltd., 2008