0:00:02 > 0:00:04CHATTER FROM NEWSROOM
0:00:04 > 0:00:08'I'm Bill Turnbull.
0:00:08 > 0:00:11'This summer, I set out to get to the bottom of a story
0:00:11 > 0:00:13'that's captured the headlines...
0:00:15 > 0:00:17'..and it's one I've got some experience of
0:00:17 > 0:00:19'because I'm also a beekeeper.'
0:00:19 > 0:00:23- There.- Is that good?- Perfect. Oh, I hate squeezing them like that.
0:00:25 > 0:00:30'I met some scientists doing some extraordinary experiments -
0:00:30 > 0:00:32'putting tiny antennae onto bees.'
0:00:32 > 0:00:34- She's out, she's out. - There she goes.
0:00:38 > 0:00:39This is just a part of an attempt
0:00:39 > 0:00:43to understand what's happening to our bees.
0:00:43 > 0:00:45It's the biggest mystery
0:00:45 > 0:00:48to hit the countryside in living memory.
0:00:48 > 0:00:52Bees are dying in their droves and we don't know why.
0:00:54 > 0:00:56'I'm going to be examining the evidence
0:00:56 > 0:00:58'that points at three of the main suspects.
0:00:58 > 0:01:01'First, a deadly invader that's devastating colonies.'
0:01:01 > 0:01:05I know from bitter experience that if you see one of those in your beehive,
0:01:05 > 0:01:08you know you're going to be in big trouble, because they can pretty much wipe out a colony
0:01:08 > 0:01:13- in a couple of months, really, can't they?- Very short time, yes. Kiss of death, isn't it?
0:01:13 > 0:01:18'Second - pesticides, their use is causing huge controversy.
0:01:22 > 0:01:26'And finally, the changes we have made in how we farm our land.
0:01:26 > 0:01:28'What is clear is that these extraordinary
0:01:28 > 0:01:31'creatures are dying in their billions.'
0:01:31 > 0:01:34This is a film about what's killing them.
0:01:54 > 0:01:57I've been keeping bees for better or worse for 12 years now.
0:01:57 > 0:02:01I've always found them to be beautiful, intricate creatures.
0:02:01 > 0:02:06Think of this - a bee in a single day will visit several thousand flowers.
0:02:06 > 0:02:09Its wings will beat at 200 times a second,
0:02:09 > 0:02:13they'll fly 15 miles an hour up to four miles from the hive
0:02:13 > 0:02:17in the search for food, and yet they'll always find their way home.
0:02:17 > 0:02:20And this for my bees is home.
0:02:23 > 0:02:27They don't live very long - on average just a few weeks in the summertime -
0:02:27 > 0:02:34but in that time, they'll fly 400, maybe 500 miles in total.
0:02:34 > 0:02:41And here's the best part, they're the only insect to provide us
0:02:41 > 0:02:43with food,
0:02:43 > 0:02:47in the form of liquid gold - honey.
0:02:48 > 0:02:51But our bees are clearly in trouble.
0:02:55 > 0:02:58'I've come to Heather Hills Farm in Perthshire
0:02:58 > 0:03:02'to meet commercial honey producer Mark Noonan
0:03:02 > 0:03:05'and to find out what's been happening to his bees.'
0:03:06 > 0:03:09You've got a fair number of bees down here, haven't you?
0:03:09 > 0:03:11Yes, this is one of our sites
0:03:11 > 0:03:15just outside Blairgowrie and we've probably got about 40 hives here.
0:03:15 > 0:03:17They've been here for about three or four weeks.
0:03:19 > 0:03:22'It's June and Mark is lending his bees
0:03:22 > 0:03:26'to a local farmer to pollinate hundreds of acres of raspberries.'
0:03:27 > 0:03:30So what is the deal between you and the farmer, then, here?
0:03:30 > 0:03:33Well, it's a natural symbiosis where he knows that
0:03:33 > 0:03:37if our bees pollinate his fruit, he'll get a lot more fruit.
0:03:37 > 0:03:40He'll get a better quality of fruit and we get
0:03:40 > 0:03:43the nectar from the raspberries, which makes a fantastic honey.
0:03:45 > 0:03:48'It's a deal that works well for the bees and for the farmer.'
0:03:50 > 0:03:52So these have been in full flower the last two or three weeks.
0:03:52 > 0:03:56As you can see, the fruit has started to form already.
0:03:56 > 0:03:59It's looking really healthy, there's nice shape to the berries there.
0:03:59 > 0:04:03And that's going to produce tonnes of raspberries.
0:04:06 > 0:04:09'But all is not well at Heather Hills Farm.
0:04:12 > 0:04:16'Mark's bees are dying and he has the empty hives to prove it.'
0:04:17 > 0:04:19So you've had a tough year?
0:04:19 > 0:04:24We have, Bill, yeah, it's been an incredibly bad winter
0:04:24 > 0:04:28and that's compounded with probably the worst summer
0:04:28 > 0:04:31- we've ever had as well last year.- Right.
0:04:31 > 0:04:35So these boxes should all be out, full of bees working?
0:04:35 > 0:04:38Yeah, they've been brought back from the fields
0:04:38 > 0:04:42because the bees didn't survive the winter, which went right on to May.
0:04:42 > 0:04:45It must have been devastating.
0:04:45 > 0:04:46It was very depressing, yeah.
0:04:46 > 0:04:49We reckon we lost 300 or 400 hives just this last winter.
0:04:49 > 0:04:53And we've had five bad years in a row.
0:04:53 > 0:04:58So Heather Hills should have 1,300 hives in operation
0:04:58 > 0:05:02at this time of year, and we've got less than half of that.
0:05:02 > 0:05:06And that's pretty common throughout not just Scotland
0:05:06 > 0:05:07but the whole of the UK.
0:05:07 > 0:05:10- I've heard stories of someone losing 96%.- Right.
0:05:10 > 0:05:11BUZZING
0:05:11 > 0:05:14And one less bee there! It just flew in my ear.
0:05:14 > 0:05:17So a very difficult position for you.
0:05:17 > 0:05:19What are you going to do to survive?
0:05:20 > 0:05:24Come and have a look. Here we have some imported bees,
0:05:24 > 0:05:26just arrived this morning all the way from Italy.
0:05:26 > 0:05:30They've probably been on the road for two or three days, I would have said.
0:05:30 > 0:05:33I would think they're pretty fed up by now, aren't they?
0:05:35 > 0:05:37'Seeing this really brings home to me
0:05:37 > 0:05:39'the problem that we have with bees here.
0:05:44 > 0:05:47'Mark's loss is an all-too-familiar story that's being
0:05:47 > 0:05:49'replicated around Britain.
0:05:52 > 0:05:53'Today I'm going to help him
0:05:53 > 0:05:57'put a hundred thousand newly arrived bees into his hives.'
0:05:59 > 0:06:03- That's it.- In you go, girls. - That's it.
0:06:11 > 0:06:14I don't like banging them around, but I suppose it has to be done.
0:06:14 > 0:06:18It has to be done and that's a kilo and a half of bees.
0:06:18 > 0:06:20- Will they be all right in there? - Yeah, yeah.
0:06:23 > 0:06:27'Mark puts the losses on his farm down to the bad summers
0:06:27 > 0:06:28'we've had in recent years.'
0:06:31 > 0:06:35The thing is, bees are very sensitive to the weather. If the temperature falls
0:06:35 > 0:06:39below 14 degrees or if it rains, they just won't leave the hive.
0:06:39 > 0:06:43The nectar output of flowers is also temperature-dependent,
0:06:43 > 0:06:46so if it's colder, there will be less nectar and therefore less food.
0:06:46 > 0:06:48And if the weather's bad
0:06:48 > 0:06:51when new virgin queens go on their mating flight, it can mean
0:06:51 > 0:06:56poor fertilisation and a weaker colony which may eventually die out.
0:06:56 > 0:06:59Add all these factors together and a bad summer can mean
0:06:59 > 0:07:03the bees will fail to survive a mild winter, let alone a harsh one.
0:07:05 > 0:07:08'The number of honeybee hives in England alone
0:07:08 > 0:07:12'fell by around about 50% between 1985 and 2005.
0:07:12 > 0:07:17'Different studies indicate a decline in total bee numbers
0:07:17 > 0:07:19'over the past 50 to 80 years.
0:07:21 > 0:07:24'So in terms of the weather on its own, it clearly doesn't
0:07:24 > 0:07:27'explain what's killing our bees - there have to be other factors.'
0:07:35 > 0:07:37CHATTER IN NEWSROOM
0:07:39 > 0:07:42'My colleagues at BBC Breakfast think I'm a bit obsessed.
0:07:44 > 0:07:47'But I want to give them a sense of what could happen
0:07:47 > 0:07:48'if we keep losing our bees.
0:07:53 > 0:07:56'It's Monday morning and the Breakfast crew have been up
0:07:56 > 0:07:57'since before dawn.
0:08:03 > 0:08:06'This is our normal breakfast, but not today.'
0:08:09 > 0:08:12Right, chaps, here comes breakfast.
0:08:12 > 0:08:14'Today they're going to be offered a menu
0:08:14 > 0:08:18'which only includes food that doesn't need bees to produce it.'
0:08:18 > 0:08:21Right, help yourselves, tuck in.
0:08:21 > 0:08:24- No butter.- No butter.
0:08:24 > 0:08:26Dry toast. I feel like I'm in prison.
0:08:26 > 0:08:29Mmm. Thank you.
0:08:29 > 0:08:32- No milk with my tea? - No milk.- No milk.
0:08:32 > 0:08:38You may be wondering what else there is. Do you want to know what else there is?
0:08:38 > 0:08:40- Go on.- Nothing. That's your lot.
0:08:40 > 0:08:42'All they have to choose from this morning is brown bread,
0:08:42 > 0:08:45'white bread and black tea.'
0:08:45 > 0:08:47We just want some fruit.
0:08:47 > 0:08:49No fruit. There's no fruit available today.
0:08:49 > 0:08:54- Could I have some tomatoes on my toast?- Tomatoes, no. No, absolutely no tomatoes.
0:08:54 > 0:08:55It's a fruit pollinated by bees.
0:08:55 > 0:08:57Like it? Are you enjoying your meal?
0:08:57 > 0:08:58LAUGHTER
0:08:58 > 0:09:00- Not really.- No.
0:09:00 > 0:09:03- It's a little bit dry, Bill.- OK.- Bit bland.
0:09:04 > 0:09:06You may know, I've been looking into, er,
0:09:06 > 0:09:09the disappearance of our bees and what's been going wrong,
0:09:09 > 0:09:12and I thought I'd have a... an experiment to see what the impact
0:09:12 > 0:09:17would be on our lives if there were no honeybees here in Britain.
0:09:17 > 0:09:19And this is the result.
0:09:19 > 0:09:24So, without bees, not much pollination goes on,
0:09:24 > 0:09:26so that's all that you're left with.
0:09:26 > 0:09:29But to make up for it, here's the breakfast that you can have
0:09:29 > 0:09:32- while we've still got honeybees. - CHEERING
0:09:32 > 0:09:35- So tuck in.- That's good.
0:09:35 > 0:09:38'To be honest, this is a bit of a treat - it's not what they're used to.
0:09:41 > 0:09:44'Take away bees and you risk losing this.
0:09:45 > 0:09:49'Most fruit, but not bananas and pineapples.
0:09:49 > 0:09:53'And most vegetables, along with protein-rich beans.
0:09:53 > 0:09:57'And because most animal feed is made from plants pollinated by bees,
0:09:57 > 0:10:01'it means meats and dairy products could also become more scarce.'
0:10:03 > 0:10:06So, we really do need to save the bees if, er,
0:10:06 > 0:10:08we want to have breakfasts like this.
0:10:08 > 0:10:11'It does give you a sense of just how important bees are.
0:10:13 > 0:10:15'I want to track down the most ground-breaking research
0:10:15 > 0:10:18'into what's killing our bees in such numbers.
0:10:27 > 0:10:30'I'm starting at a rather special place.
0:10:30 > 0:10:35'Rothamsted Research - they've been studying bees here for 90 years
0:10:35 > 0:10:39'and they've recently invented some rather ingenious ways of observing them.
0:10:40 > 0:10:43'I'm here to look at the first suspect in our mystery...
0:10:44 > 0:10:45'..the varroa mite.'
0:10:46 > 0:10:49This tiny parasite has led to the spread of some of the most
0:10:49 > 0:10:53contagious and widely distributed viruses on the planet,
0:10:53 > 0:10:59killing billions of bees and truly earning its name - Varroa destructor.
0:10:59 > 0:11:01It can be utterly devastating.
0:11:03 > 0:11:06'The first step is to try to really understand the enemy.'
0:11:08 > 0:11:09Poor little bee.
0:11:11 > 0:11:15So, Jean, where is it on this bee there?
0:11:15 > 0:11:18OK, I think if you look, even with a naked eye, just to this side
0:11:18 > 0:11:19of the abdomen.
0:11:19 > 0:11:23- Yes, oh, on the belly there? - That brick-red-coloured...- OK.
0:11:25 > 0:11:31Gosh, it looks like it is carrying a football on its stomach, isn't it?
0:11:31 > 0:11:34It's huge. It's at least two millimetres across.
0:11:35 > 0:11:38So they hang on there and they sort of feed on the...
0:11:38 > 0:11:41Puncture the soft tissue and then start...
0:11:41 > 0:11:44- Feeding on the bodily fluids. - That's right.
0:11:44 > 0:11:46I know, from bitter experience,
0:11:46 > 0:11:48when you find one of those, you're going to be in big trouble,
0:11:48 > 0:11:52cos they can pretty much wipe out a colony in a couple of months, really, can't they?
0:11:52 > 0:11:55Very short time, yes. Kiss of death, isn't it?
0:11:57 > 0:12:01'Jean Devonshire uses one of the most powerful instruments
0:12:01 > 0:12:03'in her lab - a scanning electron microscope.
0:12:05 > 0:12:09'She freezes the bee with liquid nitrogen,
0:12:09 > 0:12:12'then coats it with an ultra-fine layer of conductive gold.
0:12:14 > 0:12:18'Now we can view every tiny detail of our enemy.'
0:12:20 > 0:12:24What we're looking at now in the centre of the image there
0:12:24 > 0:12:31is the actual varroa, and if I focus it finer,
0:12:31 > 0:12:35we can see the hairs on the body obviously very easily there.
0:12:35 > 0:12:40You can see these sternal plates and the varroa sitting in the centre.
0:12:40 > 0:12:44And the head is digging in there, so it's feeding now?
0:12:44 > 0:12:46It's probably... It's probably... Yeah.
0:12:46 > 0:12:51The varroa knows that if it slides itself underneath these plates,
0:12:51 > 0:12:54it can actually puncture the soft tissue parts.
0:12:57 > 0:13:02'The varroa mite arrived in the UK in 1992. Its spread has generally
0:13:02 > 0:13:06'been linked to infected bees being imported around the world.
0:13:06 > 0:13:09'And our bees had no resistance.'
0:13:09 > 0:13:14Once it's finished munching, it leaves these open sores, which then
0:13:14 > 0:13:18leaves the bee open to infection, so it's a clever little fiend, isn't it?
0:13:18 > 0:13:20It is.
0:13:20 > 0:13:24'Thankfully, the mite on its own can be treated.
0:13:24 > 0:13:27'But when you look more closely, you can see what could be
0:13:27 > 0:13:28'the real culprit...
0:13:31 > 0:13:32'..a virus.'
0:13:34 > 0:13:37Here are the virus particles.
0:13:37 > 0:13:41We're looking at this at about 40,000 times magnification.
0:13:41 > 0:13:45Obviously there will be a lot of them in their body,
0:13:45 > 0:13:48which will eventually cause their demise.
0:13:51 > 0:13:54'And this is the sort of thing they can do.
0:13:54 > 0:13:57'This bee is suffering from deformed wing virus.
0:13:57 > 0:13:59'You can see pretty easily what's happened to it.
0:14:00 > 0:14:03'But what makes the varroa mite so sinister
0:14:03 > 0:14:06'is that it can cause something much more difficult to spot.'
0:14:11 > 0:14:13The viruses carried by varroa mites
0:14:13 > 0:14:16can have all-too-obvious, devastating effects
0:14:16 > 0:14:19but, in reality, these are only seen in extreme cases.
0:14:19 > 0:14:23And what worries researchers now is that these may be just
0:14:23 > 0:14:27a tiny minority of all infections and that many more bees,
0:14:27 > 0:14:30apparently healthy, may be affected by them
0:14:30 > 0:14:34in less visible ways, which are just as devastating for the colony.
0:14:37 > 0:14:40'What they're trying to find out here is what happens
0:14:40 > 0:14:43'to these infected bees once they leave the hive.
0:14:47 > 0:14:50'To do that, they've invented something pretty remarkable.'
0:14:53 > 0:14:54Jason, it looks like we have some kind of
0:14:54 > 0:14:56military espionage station here. What is it?
0:14:56 > 0:14:59Well, this is a specially designed radar that we developed that
0:14:59 > 0:15:03allows us to track the flight paths of bees once they leave their hive.
0:15:03 > 0:15:05You can very easily study what happens
0:15:05 > 0:15:07when the bees come back to the hive and leave
0:15:07 > 0:15:10but what happened when they were on their foraging flights
0:15:10 > 0:15:13at some distance away was always a great challenge to study
0:15:13 > 0:15:16and it wasn't until we developed a system such as this radar
0:15:16 > 0:15:19that we were able to accurately track their flight paths
0:15:19 > 0:15:23over distances of hundreds of metres, even up to a kilometre or so.
0:15:23 > 0:15:27How does it work, then? There are millions of insects out there
0:15:27 > 0:15:31in the area that you're sweeping, but you target specific individuals?
0:15:31 > 0:15:33That's right, and so we have an individual honeybee
0:15:33 > 0:15:37which will be carrying this very small, fine antenna on its back
0:15:37 > 0:15:41and as the wavelength of the emitted radar beam hits that,
0:15:41 > 0:15:45the little diode in the centre converts the incoming signal
0:15:45 > 0:15:48to a unique signal which is half of the wavelength
0:15:48 > 0:15:52and so we can listen to that signal with a special receiver dish,
0:15:52 > 0:15:54and therefore just track the individual insect
0:15:54 > 0:15:56without it being swamped by echo.
0:15:56 > 0:16:00That is almost as long as a bee itself.
0:16:00 > 0:16:02Isn't it a bit too big for it?
0:16:02 > 0:16:05Honeybees have evolved over millions of years to carry heavy loads.
0:16:05 > 0:16:08They can carry pollen loads almost half their body weight
0:16:08 > 0:16:11and this tag only weighs about a tenth of the body weight
0:16:11 > 0:16:13so it's very easy for them to carry that weight
0:16:13 > 0:16:15and it doesn't affect their behaviour in any way.
0:16:17 > 0:16:20'But for me, seeing is believing.
0:16:20 > 0:16:24'The man at the other end of the experiment is Dr Stephan Wolf.'
0:16:24 > 0:16:28- So, here we have the bee.- Yes.- She can't get through there, can she?
0:16:28 > 0:16:30- She can, but...- OK.- ..you know.
0:16:30 > 0:16:33It's just trial... We'll be here all day!
0:16:33 > 0:16:35- There!- Yeah.- Is that good? - Perfect, wonderful.- OK.
0:16:35 > 0:16:37I just...hate squeezing them like that.
0:16:37 > 0:16:40Hold the transponder at the white bit.
0:16:40 > 0:16:42- At the white bit?- Yes. - At the bottom, OK.
0:16:42 > 0:16:45OK, and just stick it on there, really lightly.
0:16:47 > 0:16:50- Like that?- There we are. - And down she goes, go on.
0:16:50 > 0:16:51It's a bit like running round
0:16:51 > 0:16:54- with broomsticks on the back of your head, isn't it?- Perhaps.
0:16:56 > 0:16:59'This technology has already revealed some of the secrets
0:16:59 > 0:17:01'of the life of a bee.
0:17:01 > 0:17:05'In particular, one of the great mysteries about these creatures -
0:17:05 > 0:17:07'how, when they first leave the hive,
0:17:07 > 0:17:10'they manage to find their way out and their way back,
0:17:10 > 0:17:15'visiting up to 2,000 flowers in a day, without getting lost.'
0:17:17 > 0:17:19She's in a landscape that she's never seen before
0:17:19 > 0:17:22so she starts with very small loops in the beginning around the hive,
0:17:22 > 0:17:27and then extends these loops ever further in order to build up
0:17:27 > 0:17:30a memory of the landscape that will enable her to get back to the hive.
0:17:33 > 0:17:38And here it is, the flight of the humble bee.
0:17:38 > 0:17:41This is what's called its exploratory path,
0:17:41 > 0:17:46the route it takes as it circles around the hive for the first time.
0:17:47 > 0:17:49Over several days it builds up a mental map
0:17:49 > 0:17:52of more than ten square kilometres around the hive.
0:17:56 > 0:17:59The radar allows us to see this with unprecedented precision.
0:18:03 > 0:18:06What's been found is that their orientation flight
0:18:06 > 0:18:09is very, very efficient, to explore the biggest area
0:18:09 > 0:18:11with the shortest time effort
0:18:11 > 0:18:13and the shortest energy effort, obviously.
0:18:16 > 0:18:19'I'm here to see Stephan's latest experiment.
0:18:20 > 0:18:23'He wants to find out if the viruses carried by the varroa mite
0:18:23 > 0:18:28'will affect how the bees fly. And that's important,
0:18:28 > 0:18:31'because if they can't navigate properly, some of them will die.'
0:18:33 > 0:18:35So, what we have, we have a colony in here,
0:18:35 > 0:18:39and in that colony live bees which have various levels of diseases.
0:18:39 > 0:18:41These bees have only lived in that cage.
0:18:41 > 0:18:44They don't know the landscape around.
0:18:44 > 0:18:48'The bees here are all healthy enough to fly. The question is,
0:18:48 > 0:18:52'does the virus affect their exploratory flight?'
0:18:52 > 0:18:56So, here you have a not-quite-so-willing volunteer.
0:18:56 > 0:19:01- Nearly dropped her there!- OK, Jason. The bee's equipped. Have a look.
0:19:01 > 0:19:04- JASON ON RADIO:- Oh, yeah. There. - Here she goes.
0:19:04 > 0:19:08- OK, Jason. She's out, she's out. - Warming up a bit.
0:19:13 > 0:19:14There she goes.
0:19:14 > 0:19:16OK, she's off, she's off, Jason.
0:19:16 > 0:19:19OK, bee is flying, the one bee is flying.
0:19:19 > 0:19:22Flying away from the cage.
0:19:22 > 0:19:23She's out there somewhere.
0:19:23 > 0:19:25- You definitely saw her taking off, did you?- Yes.
0:19:25 > 0:19:29Bee's making a loop. Er, bee stopped, bee stopped.
0:19:29 > 0:19:32'As bee number one goes to ground for a while,
0:19:32 > 0:19:35'it's my chance to head for the radar station across the field.'
0:19:35 > 0:19:38- Hi, Jason.- Hello.- How's it going? - Yep, fine.- Right.
0:19:38 > 0:19:42'To the bottom left of the screen, a red spot marks the position
0:19:42 > 0:19:45'of the hive just over 200 metres from the radar.'
0:19:45 > 0:19:46300 metres away, now.
0:19:48 > 0:19:51'And each time the radar sweeps past,
0:19:51 > 0:19:53'a white mark reveals the position of the bee.'
0:19:53 > 0:19:57OK, bee is coming back, the white bee is coming back.
0:19:57 > 0:20:01'The radar records each successive loop the bee makes,
0:20:01 > 0:20:04'until she returns safely to the hive.'
0:20:04 > 0:20:06The bee is at hive, the bee is at hive, Stephan.
0:20:06 > 0:20:10- So, now the bee's come back to the hive?- Yes, exactly. Yes.
0:20:16 > 0:20:18'Over the summer, Stephan and his colleagues
0:20:18 > 0:20:20'will be trying to find out if the virus
0:20:20 > 0:20:24'DOES affect the bees' flight. We'll have to wait for those results.
0:20:27 > 0:20:29'But this system, which allows us to track bees
0:20:29 > 0:20:31'in a way we've never done before,
0:20:31 > 0:20:34'should provide some important clues.'
0:20:39 > 0:20:43We can test for whether the flights are close to an optimal flight or not.
0:20:43 > 0:20:45This is what we want to show with this experiment,
0:20:45 > 0:20:48whether the diseases actually do change one
0:20:48 > 0:20:51or all of these aspects, or perhaps none.
0:20:53 > 0:20:55What we do know about the varroa mite then,
0:20:55 > 0:20:58is that it has killed billions of bees.
0:20:58 > 0:21:00We know it does spread viruses
0:21:00 > 0:21:04but we don't yet know what the full effect of those viruses may be.
0:21:07 > 0:21:10'But I don't think this is the whole picture...not yet.'
0:21:19 > 0:21:22Professor Simon Potts has brought me
0:21:22 > 0:21:25to the Oxford University Museum of Natural History...
0:21:27 > 0:21:31..to show me one of the biggest collections of bees in the UK.
0:21:33 > 0:21:34Some of these don't look like bees...
0:21:34 > 0:21:37- well, like the bees that we would expect.- No, exactly.
0:21:37 > 0:21:40So it's because they're incredibly diverse in what they do.
0:21:40 > 0:21:44Here's a really good example of how big a variety you get.
0:21:44 > 0:21:45We actually have 250 species,
0:21:45 > 0:21:48which many people will be surprised about.
0:21:48 > 0:21:50Some people will see honeybees in the garden,
0:21:50 > 0:21:54maybe the occasional bumblebee, but actually there's 250 to look at.
0:21:56 > 0:21:59Some of these look terribly small, almost as if they're mosquitoes.
0:21:59 > 0:22:01Yeah, they could do,
0:22:01 > 0:22:03but as you get to see them they've got two pairs of wings
0:22:03 > 0:22:08- and actually they are proper bees. - How do you define "bee", then?
0:22:08 > 0:22:10- So, er... - BILL LAUGHS
0:22:12 > 0:22:14Well, essentially it's a hymenoptera
0:22:14 > 0:22:16so it has a small, pinched waist that you can see.
0:22:16 > 0:22:19- All of these bees have that. - They're always very particular
0:22:19 > 0:22:21- about their figure, bees, aren't they? They have a waist.- Yes.
0:22:21 > 0:22:24They do a lot of flying around, burning off a lot of calories.
0:22:24 > 0:22:27And they go out and they collect pollen and nectar
0:22:27 > 0:22:28so they're vegetarian
0:22:28 > 0:22:31whereas their kind of close relatives, the wasps,
0:22:31 > 0:22:33they're very often carnivorous.
0:22:33 > 0:22:35And when it comes to crop pollination,
0:22:35 > 0:22:37these are the unsung heroes of the pollination world.
0:22:37 > 0:22:40Honeybees DO make a contribution but actually it's the wild bees
0:22:40 > 0:22:43particularly that are doing most of the work.
0:22:43 > 0:22:46So for instance, in the UK, think about the huge areas of oil seed
0:22:46 > 0:22:49and beans and apple crops and also all the soft fruits we have.
0:22:49 > 0:22:51We've only got enough honeybees
0:22:51 > 0:22:55to pollinate an absolute maximum, a third. So, who does the rest?
0:22:55 > 0:22:58It's these guys. They work so hard to ensure that we get
0:22:58 > 0:23:01everything pollinated. Not just crops, but all our wild flowers.
0:23:01 > 0:23:06- Do these bees suffer from varroa? - They don't suffer from varroa
0:23:06 > 0:23:08but these guys are in real trouble as well.
0:23:08 > 0:23:09It seems what you're saying is
0:23:09 > 0:23:12- even if we sorted out the varroa problem...- Mm-hmm?
0:23:12 > 0:23:15- ..we'd still have a major issue on our hands?- Absolutely.
0:23:24 > 0:23:27The honeybee and hundreds of other species, are all in decline.
0:23:32 > 0:23:35But those other species don't suffer from the varroa mite.
0:23:42 > 0:23:44There's no doubt that varroa is lethal.
0:23:44 > 0:23:47As it's spread across the globe over the past 50 years,
0:23:47 > 0:23:50it's resulted in the death of billions of honeybees.
0:23:50 > 0:23:52In some countries, including the United States,
0:23:52 > 0:23:56it's been linked to the disappearance of entire colonies -
0:23:56 > 0:23:58what they call colony collapse disorder.
0:23:58 > 0:24:00Here in Britain, though, it's a rather different story.
0:24:00 > 0:24:05For a start, varroa only affects honeybees, not wild bees,
0:24:05 > 0:24:08and they've been in decline here as well for some time.
0:24:08 > 0:24:12And crucially, it only arrived here about 20 years ago
0:24:12 > 0:24:15and we know our bees have been dying off for much longer than that.
0:24:15 > 0:24:19So, while it's true that varroa has put an added strain
0:24:19 > 0:24:22on the honeybees, the evidence would indicate
0:24:22 > 0:24:25that it's not responsible for the whole problem.
0:24:30 > 0:24:34Our second suspect, pesticides, are the most controversial.
0:24:37 > 0:24:41This year, the European Commission announced the two-year ban
0:24:41 > 0:24:44on the use of certain pesticides called neonicotinoids.
0:24:45 > 0:24:48They said the evidence now showed that they were
0:24:48 > 0:24:52an unacceptable danger to bees feeding on flowering crops.
0:24:57 > 0:25:01And THIS is what's generating more heat than anything else -
0:25:01 > 0:25:03neonicotinoid pesticides.
0:25:03 > 0:25:07Often, they come coated on the seeds, like on this rape seed,
0:25:07 > 0:25:09so that as the plant grows,
0:25:09 > 0:25:12the chemical spreads throughout the organism through the roots,
0:25:12 > 0:25:15the leaves, the flowers, even to the nectar and the pollen.
0:25:15 > 0:25:19Now one of the terms scientists use to measure just how lethal
0:25:19 > 0:25:24these things are is called "LD50" - the dose that is lethal to 50%,
0:25:24 > 0:25:26half of the test subjects.
0:25:26 > 0:25:28And the lethal dose for a bee
0:25:28 > 0:25:30is just four billionths of a gram,
0:25:30 > 0:25:33which raises an important question,
0:25:33 > 0:25:36just what are these things doing to our bees?
0:25:38 > 0:25:43Neonicotinoids are nerve agents, and they only affect insects.
0:25:43 > 0:25:47They were introduced in the 1990s to replace more harmful pesticides.
0:25:47 > 0:25:49When used properly,
0:25:49 > 0:25:53they cause deadly paralysis in small pests like aphids.
0:25:53 > 0:25:55But if they do that to aphids...
0:25:56 > 0:25:59..what's the effect on the bees?
0:26:09 > 0:26:12There's a scientist in Germany investigating just that.
0:26:15 > 0:26:1840 years of research have made Professor Randolf Menzel
0:26:18 > 0:26:21a global authority on the nervous system of bees.
0:26:24 > 0:26:26One thing that's excited him for many years
0:26:26 > 0:26:28is just how advanced their communication is.
0:26:30 > 0:26:33Especially their famous waggle dance.
0:26:36 > 0:26:40Returning from a foraging trip, this bee is telling its co-workers
0:26:40 > 0:26:42precisely where she found her pollen.
0:26:45 > 0:26:47They just use the body to, uh,
0:26:47 > 0:26:50inform the others about any important place
0:26:50 > 0:26:51out in the field -
0:26:51 > 0:26:54a wonderful flower or a pollen place.
0:26:56 > 0:26:59As she circles, the bee repeatedly waggles
0:26:59 > 0:27:03during one phase of her dance. Here, walking straight upwards.
0:27:06 > 0:27:11It is this phase which codes the direction relative to the sun
0:27:11 > 0:27:13and the distance.
0:27:16 > 0:27:19Walking upwards while she waggles, tells the other bees
0:27:19 > 0:27:21to head towards the sun.
0:27:21 > 0:27:24The number of times she moves from side to side,
0:27:24 > 0:27:27tells them how far to fly.
0:27:28 > 0:27:31The brain controlling this sort of behaviour
0:27:31 > 0:27:33is clearly rather sophisticated.
0:27:35 > 0:27:38This kind of cognitive processing requires the highest order
0:27:38 > 0:27:42of neural processing in this little brain.
0:27:42 > 0:27:45That means anything which is disturbing
0:27:45 > 0:27:50on these fine network processes should have a high impact.
0:28:00 > 0:28:04With the radar technology, Randolf and his team have been investigating
0:28:04 > 0:28:08whether neonicotinoids could affect bees' brains.
0:28:10 > 0:28:15They're testing their ability to find their way home after feeding.
0:28:17 > 0:28:18This is our feeding place.
0:28:18 > 0:28:21That means bees have been trained from the hive,
0:28:21 > 0:28:24and we train them step-wise to this location.
0:28:26 > 0:28:31We catch it in the moment it arrives here, put it into a container
0:28:31 > 0:28:38like this which con...contains 50 microlitres of sugar solution.
0:28:41 > 0:28:44The bees are fed one of two different solutions.
0:28:47 > 0:28:50We have groups which are fed with the pesticide
0:28:50 > 0:28:52delivered in the sugar solution,
0:28:52 > 0:28:55and other groups which are not fed with the pesticide.
0:28:55 > 0:28:57And we compare them.
0:28:57 > 0:29:00The bees have made many trips to the feeding station.
0:29:00 > 0:29:03And that means they know how to fly in a straight line
0:29:03 > 0:29:05between here and the hive.
0:29:05 > 0:29:10They do this on auto-pilot, using what's known as their vector memory.
0:29:10 > 0:29:13So, when she is ready, uh, to take off,
0:29:13 > 0:29:17she will just fly back to the hive using her vector memory.
0:29:17 > 0:29:19That's all that she would do.
0:29:19 > 0:29:23And she expect the hive in 500 metres in the northwest.
0:29:24 > 0:29:28But today, Randolf is setting out to confuse the bees a bit.
0:29:30 > 0:29:33He's going to take them several hundred metres away from
0:29:33 > 0:29:35the place where they normally feed.
0:29:36 > 0:29:39And then track their attempts to get back to the hive.
0:29:41 > 0:29:43OK, we are at release site now.
0:29:43 > 0:29:46So, let's say that this is the release site.
0:29:46 > 0:29:49The feeding station was over there
0:29:49 > 0:29:52and this is the hive in this direction.
0:29:52 > 0:29:55So, let's say this is the feeding station, this is the hive,
0:29:55 > 0:29:59and they have learnt to fly along this vector over 500 metres.
0:29:59 > 0:30:02Now, we release them here.
0:30:02 > 0:30:06Which means they use their memory for the vector
0:30:06 > 0:30:10and that means they fly along this route.
0:30:10 > 0:30:12But when they arrive there, there is no hive.
0:30:12 > 0:30:16So, the question is, if the animal's released here,
0:30:16 > 0:30:17how do they find home,
0:30:17 > 0:30:20and what is the effect of pesticides on this behaviour?
0:30:22 > 0:30:27First, he releases a control bee that hasn't been fed the pesticide.
0:30:32 > 0:30:36As the bee tries to find her way home, she's tracked by the radar.
0:30:38 > 0:30:42She flies on auto-pilot 500 metres northwest.
0:30:43 > 0:30:46She gets to where she thinks the hive should be...
0:30:47 > 0:30:49but because it's not there,
0:30:49 > 0:30:52she has to use a different navigation system to find it.
0:30:54 > 0:30:58One that uses landmarks in the countryside to find her way home.
0:31:00 > 0:31:03So, she is... is still flying towards the hive?
0:31:03 > 0:31:06- Yeah, she's landing there now. - OK, she has arrived already.
0:31:06 > 0:31:09- I think she's already here. - OK, she is already there.
0:31:14 > 0:31:16Before she can disappear into the hive,
0:31:16 > 0:31:18our radar bee is intercepted
0:31:18 > 0:31:20and the antenna is removed.
0:31:25 > 0:31:29Next is a bee that HAS been fed on the pesticide.
0:31:37 > 0:31:40It quickly becomes apparent that something is up.
0:31:41 > 0:31:45So that means she comes back. She turns back towards north.
0:31:48 > 0:31:50Rather than heading straight home,
0:31:50 > 0:31:52she starts to make a series of
0:31:52 > 0:31:54erratic changes of course.
0:31:56 > 0:31:59West. OK.
0:32:01 > 0:32:03Where is she now?
0:32:03 > 0:32:06So she is flying further north.
0:32:06 > 0:32:10After a few minutes, the bee appears to be completely lost.
0:32:12 > 0:32:16She's cruising around us, undecided which direction to fly.
0:32:16 > 0:32:20She has not done what we expected of her to do,
0:32:20 > 0:32:23to fly along the vector direction,
0:32:23 > 0:32:26which would have meant that she would fly exactly in this direction.
0:32:29 > 0:32:33Over two years of study, Randolf's shown that, at these doses,
0:32:33 > 0:32:37neonicotinoids DO affect bees' higher cognitive processes.
0:32:38 > 0:32:42Especially their memory of the landscape around them.
0:32:42 > 0:32:45We've tested about 200 bees, both control bees and, uh,
0:32:45 > 0:32:47pesticide treated bees.
0:32:47 > 0:32:49And we found the control bees are just fantastic.
0:32:49 > 0:32:50They find home quickly,
0:32:50 > 0:32:54they use the vector and the landscape memory and they do fine.
0:32:54 > 0:32:58Now, the treated bees, depending on doses and substance,
0:32:58 > 0:33:01we find that they are kind of more confused.
0:33:01 > 0:33:05They usually do quite well when they fly along the vector,
0:33:05 > 0:33:08but when they need to refer to the landscape memory,
0:33:08 > 0:33:09then usually they are lost.
0:33:11 > 0:33:15They change their behaviour in a very strong way. And so that simply
0:33:15 > 0:33:21means to me, that neonicotinoids ARE endangering honeybees.
0:33:24 > 0:33:28It's work like this that lies behind the European Commission ban.
0:33:30 > 0:33:33But one thing I've learned in this detective story,
0:33:33 > 0:33:36is that it's all too easy to jump to conclusions.
0:33:38 > 0:33:40Despite this research, though,
0:33:40 > 0:33:44neonicotinoids are still at the centre of a HUGE controversy.
0:33:50 > 0:33:54The UK Government did not support the EC ban on neonicotinoids,
0:33:54 > 0:33:57it said there wasn't enough evidence to justify it.
0:33:59 > 0:34:02Let's find ways of how farming can co-exist with nature.
0:34:02 > 0:34:04This is what we're talking about.
0:34:04 > 0:34:09'As a beekeeper and journalist, it's a debate I've followed very closely.
0:34:10 > 0:34:12'Tonight, the British Library
0:34:12 > 0:34:15'has asked me to host a discussion on the subject.'
0:34:15 > 0:34:17We are facing a difficult situation
0:34:17 > 0:34:20with bees and other pollinators in Britain, at the moment.
0:34:20 > 0:34:23'The argument in favour of a ban was made by one of the scientists
0:34:23 > 0:34:25'on the panel.'
0:34:27 > 0:34:30There are these pieces of evidence which show really serious impacts
0:34:30 > 0:34:33from levels of neonicotinoids that bees,
0:34:33 > 0:34:37wild bees could be exposed to in the wider environment.
0:34:37 > 0:34:40'And the argument against the ban was laid out
0:34:40 > 0:34:42'by one of the pesticide manufacturers.'
0:34:42 > 0:34:46These trials show that there is no risk to, to pollinators from
0:34:46 > 0:34:49those products when they're used correctly in the environment.
0:34:50 > 0:34:52'There was a lot of concern in the audience.'
0:34:52 > 0:34:56I'm very worried I still can go into my local supermarket
0:34:56 > 0:35:02and buy litres of garden spray which contain various neonicotinoids.
0:35:03 > 0:35:05'It's clear to me
0:35:05 > 0:35:07'that even though many of the people here tonight
0:35:07 > 0:35:11'had differing opinions, there is a hunger for clarity.'
0:35:18 > 0:35:21So I'm heading back to Rothamsted...
0:35:23 > 0:35:26..where there is another group of scientists looking at pesticides
0:35:26 > 0:35:28from a completely DIFFERENT angle.
0:35:31 > 0:35:35'These dimly lit red corridors are the first line of defence
0:35:35 > 0:35:38'against a very dangerous collection of insects.'
0:35:38 > 0:35:39Why the red light?
0:35:39 > 0:35:43Insects don't really see red light, so to them this corridor is dark,
0:35:43 > 0:35:44which means
0:35:44 > 0:35:48they're not going to fly out here. It's just additional security.
0:35:48 > 0:35:49The rooms are sealed anyway...
0:35:49 > 0:35:51'Professor Lin Field wants to show me
0:35:51 > 0:35:54'how we underestimate the value of insecticides.'
0:35:54 > 0:35:56This room here.
0:35:56 > 0:35:57So what have we got here?
0:35:57 > 0:35:59OK. So this is actually a Chinese cabbage plant,
0:35:59 > 0:36:04and this is a plant that we've only just introduced the pest to,
0:36:04 > 0:36:07and this is one that's been in the cage with the pests
0:36:07 > 0:36:09for maybe a week, and you can see there's very little left.
0:36:13 > 0:36:17And with most of the crops we grow, somewhere between 30-40%
0:36:17 > 0:36:19would be lost to pests and diseases
0:36:19 > 0:36:21if we made no effort to control them.
0:36:25 > 0:36:27So in your view, we really need these pesticides?
0:36:27 > 0:36:28In my view at the moment.
0:36:28 > 0:36:30I think there are some alternatives
0:36:30 > 0:36:34but most of our crop protection does rely on modern chemistry,
0:36:34 > 0:36:37which are very effective insecticides,
0:36:37 > 0:36:40very safe, very low mammalian toxicity,
0:36:40 > 0:36:44and they play a big role in our food production systems.
0:36:48 > 0:36:52Lin's recently become Rothamsted's spokesperson
0:36:52 > 0:36:54in the neonicotinoid debate
0:36:58 > 0:37:00The big advantage of neonicotinoids,
0:37:00 > 0:37:02is that you can plant the seed already treated.
0:37:02 > 0:37:05It means the farmer doesn't have to spray.
0:37:05 > 0:37:08If you've got to spray, that's expensive,
0:37:08 > 0:37:11it's got a high carbon input, you have a risk of drift,
0:37:11 > 0:37:14you have to wait for the right weather conditions,
0:37:14 > 0:37:17whereas if the plant is protected by the chemistry
0:37:17 > 0:37:20coming up as it grows, you avoid all of those steps
0:37:20 > 0:37:23From the farmer's point of view, it's really useful.
0:37:23 > 0:37:25It is VERY useful.
0:37:25 > 0:37:28You'll be familiar with Professor Menzel's work in Germany,
0:37:28 > 0:37:31where he's shown that neonicotinoids can have
0:37:31 > 0:37:34an effect on the bees' navigational ability.
0:37:34 > 0:37:36And that may explain why we've been losing so many bees.
0:37:36 > 0:37:37It might explain it
0:37:37 > 0:37:40and I'm not in any way questioning his data.
0:37:40 > 0:37:41I think at certain levels
0:37:41 > 0:37:43they will have sub-lethal behavioural effects.
0:37:43 > 0:37:45Whether the amount that bees pick up
0:37:45 > 0:37:48by foraging in crops that are treated with neonics
0:37:48 > 0:37:51are at the same level to give that effect, I don't know,
0:37:51 > 0:37:54and I don't think that's been shown.
0:37:54 > 0:37:55Why have some of them been banned by the EU?
0:37:55 > 0:37:57In my view the lobbying -
0:37:57 > 0:38:02that went along with the fact that neonicotinoids were suspected -
0:38:02 > 0:38:05was so strong that, in the end, they got banned
0:38:05 > 0:38:08on a precautionary principle, on a just-in-case principle.
0:38:19 > 0:38:22A lot of people are looking for clear and simple answers as to
0:38:22 > 0:38:25whether neonicotinoids are to blame
0:38:25 > 0:38:28but the way that creatures as sensitive as bees interact
0:38:28 > 0:38:31with their changing environment is a complex one.
0:38:31 > 0:38:32For instance in France,
0:38:32 > 0:38:35neonicotinoids were banned for a decade
0:38:35 > 0:38:37and yet the decline continued,
0:38:37 > 0:38:41whereas in Australia the pesticides are still widely used
0:38:41 > 0:38:46and the bees remain generally healthy. It just is complex.
0:38:46 > 0:38:49For me the most important question here in Britain,
0:38:49 > 0:38:51is about dose
0:38:51 > 0:38:54and the effects that neonics are having at low levels,
0:38:54 > 0:38:57the sort of levels you'll find in the countryside.
0:39:03 > 0:39:06That's why I'm heading to East Sussex.
0:39:06 > 0:39:11'I've heard about an experiment happening right now, to establish
0:39:11 > 0:39:15'how much pesticide bees are really getting in the wild.
0:39:17 > 0:39:20'So I'm joining Professor Dave Goulson and his team,
0:39:20 > 0:39:22'to find out how they're going to do it.'
0:39:25 > 0:39:27The dispute largely focuses on the fact
0:39:27 > 0:39:31that pretty much all the experiments done today have...
0:39:31 > 0:39:35exposed the bees to the pesticides in an unnatural way.
0:39:35 > 0:39:39And what we really don't know is actually what wild bees, natural,
0:39:39 > 0:39:41free-flying bees are actually exposed to.
0:39:41 > 0:39:43Cos obviously in the real world,
0:39:43 > 0:39:46they have a choice about where they can forage.
0:39:46 > 0:39:48There are lots of different flowers around.
0:39:48 > 0:39:50They might, for example, avoid ones with pesticides in them.
0:39:50 > 0:39:53If they did, then that would mean that, actually,
0:39:53 > 0:39:55they might be exposed to less than we think.
0:39:56 > 0:40:00'To find out how much pesticide wild bees are really exposed to,
0:40:00 > 0:40:04'he's set up a series of bumblebee nests in fields around East Sussex.
0:40:06 > 0:40:09'Each started with just a handful of bees.
0:40:11 > 0:40:14'Three weeks later, they're flourishing - new colonies,
0:40:14 > 0:40:16'packed with nectar and pollen
0:40:16 > 0:40:19'collected from the surrounding fields.'
0:40:19 > 0:40:22I'm always told bumblebee stings are more painful than regular bees,
0:40:22 > 0:40:23- is that right?- I don't know.
0:40:23 > 0:40:26I don't think there's much in it, they're both... They both hurt.
0:40:26 > 0:40:29So what we need to do is get a pollen sample
0:40:29 > 0:40:31and a nectar sample and a sample of the wax.
0:40:31 > 0:40:33And then, when we've got all the samples in,
0:40:33 > 0:40:35we're going to analyse them all
0:40:35 > 0:40:37to detect these tiny traces of pesticides.
0:40:41 > 0:40:44'The bees will have this all patched up in a day or two.
0:40:44 > 0:40:48'The team will collect samples every few weeks.
0:40:48 > 0:40:49'But this will give them the first
0:40:49 > 0:40:52'REAL measure of the dose that wild bees are getting.
0:40:52 > 0:40:55'They've chosen to study bumblebees for good reason:
0:40:55 > 0:40:58'because each colony lives for just one year.'
0:41:01 > 0:41:05So the nest is founded by a queen in the spring and she rears up
0:41:05 > 0:41:08her worker daughters to start with. And then, after about three months,
0:41:08 > 0:41:14the nest produces males and new queens and the nest dies off.
0:41:14 > 0:41:16So that discrete life cycle, uh, actually enables us
0:41:16 > 0:41:19to do an experiment in just a few months and measure
0:41:19 > 0:41:22the effects of pesticides on the colony performance.
0:41:24 > 0:41:26'As well as analysing samples,
0:41:26 > 0:41:29'they're going to measure the growth of each colony.'
0:41:32 > 0:41:36So that's 674 grams.
0:41:41 > 0:41:43'They have 40 boxes in East Sussex.
0:41:43 > 0:41:46'And another 40 in Scotland.
0:41:49 > 0:41:52'Dave will be able to compare the growth rates of each colony
0:41:52 > 0:41:55'with the levels of pesticide measured in them.
0:41:55 > 0:41:58'It'll be September before the results are analysed.'
0:42:12 > 0:42:15We know the levels that are found in oilseed rape crops.
0:42:15 > 0:42:18It's between about one and six or seven parts per billion.
0:42:18 > 0:42:20What we don't know is where else
0:42:20 > 0:42:23these pesticides are in the environment.
0:42:23 > 0:42:26One of the kind of concerns is that they can last for years
0:42:26 > 0:42:28in soil. And then, subsequently,
0:42:28 > 0:42:30if flowers, wildflowers for example,
0:42:30 > 0:42:36grow in that field. So, um, poppies, in the field just here -
0:42:36 > 0:42:38that had a wheat crop in it last year
0:42:38 > 0:42:39that was treated with pesticides,
0:42:39 > 0:42:43so it seems quite likely that there'll be small amounts of
0:42:43 > 0:42:46neonicotinoids in the pollen and nectar of this poppy as well.
0:42:47 > 0:42:49So is banning neonics a good idea?
0:42:49 > 0:42:50I think that the moratorium
0:42:50 > 0:42:53that's just about to come into place is better than nothing.
0:42:53 > 0:42:55But even if we stopped using them completely right now,
0:42:55 > 0:42:58it would be years before they're gone from the environment.
0:42:58 > 0:43:01So two years is not enough to detect any kind of benefit
0:43:01 > 0:43:02to the environment from stopping using them.
0:43:02 > 0:43:06So it's very unclear how we'll decide what to do
0:43:06 > 0:43:09in two years' time and really, um,
0:43:09 > 0:43:13we've just kind of deferred the decision, as far as I can see.
0:43:20 > 0:43:24'This is one of the most important experiments taking place.
0:43:24 > 0:43:27'The one that could help us understand the degree
0:43:27 > 0:43:31'to which research done so far is relevant to bees in the wild.'
0:43:37 > 0:43:39So what do we know so far?
0:43:42 > 0:43:46There's a good argument for saying that disease and mite infestation
0:43:46 > 0:43:50could be playing a bigger role than we'd previously thought.
0:43:50 > 0:43:55The image there is the actual varroa...
0:43:55 > 0:43:59Meanwhile, the results of Professor Menzel's experiments with pesticides
0:43:59 > 0:44:01would appear to be persuasive,
0:44:01 > 0:44:03but we'll have to wait for more evidence from the work
0:44:03 > 0:44:06of people like Dave Goulson and his bumblebees before we can make
0:44:06 > 0:44:10a convincing case about the effect of neonicotinoids.
0:44:15 > 0:44:17And then you have to think about the effects that banning
0:44:17 > 0:44:21pesticides could have on agriculture and the cost of food production.
0:44:21 > 0:44:23It could end up doing more harm than good.
0:44:27 > 0:44:29With so many potential suspects, it's no wonder
0:44:29 > 0:44:33there's so much debate and confusion amongst the scientific community.
0:44:33 > 0:44:36And just as we think we're getting to the big picture,
0:44:36 > 0:44:38we've come across another entirely different
0:44:38 > 0:44:40scientific angle on the story,
0:44:40 > 0:44:43which raises the rather troubling question
0:44:43 > 0:44:46as to whether we've missed the real issue altogether.
0:44:51 > 0:44:54There are some bees which are doing surprisingly well.
0:44:57 > 0:44:59In places you might not expect.
0:45:01 > 0:45:04If we can work out why these city bees are doing well,
0:45:04 > 0:45:07it might give us the clues as to what's happening
0:45:07 > 0:45:09to the rest of the bee population.
0:45:13 > 0:45:18Steve Benbow is an urban beekeeper, and his bees seem to be doing OK.
0:45:21 > 0:45:22Now, that's pretty lovely.
0:45:24 > 0:45:28He puts that down to his honeybees' rather unusual habitat.
0:45:30 > 0:45:33We're on the roof of Tate Britain here
0:45:33 > 0:45:37and these are some of the bees that I look after for the Tate.
0:45:37 > 0:45:39I have to say, and congratulate you,
0:45:39 > 0:45:42on having really very, very polite and friendly bees.
0:45:42 > 0:45:44Here we are, standing in front of the hives
0:45:44 > 0:45:45and they're just floating around.
0:45:45 > 0:45:48I've never been able to do this with anybody else's bees.
0:45:48 > 0:45:50Oh, good. No, they are particularly polite,
0:45:50 > 0:45:53but a little bit different when you go in them.
0:45:53 > 0:45:55And they love this aspect.
0:45:55 > 0:45:56It's lovely and light and sunny
0:45:56 > 0:45:59and there's a lot of good forage in this area here.
0:45:59 > 0:46:01Is the city really a good place to keep bees?
0:46:01 > 0:46:04Most people would think, well, loads of steel and glass
0:46:04 > 0:46:07and concrete and roads and traffic in the city
0:46:07 > 0:46:09would put bees off, what are they going to feed on?
0:46:09 > 0:46:11If you look out here, there's chestnuts here
0:46:11 > 0:46:14and they'll start on those early in the year.
0:46:14 > 0:46:17And then the bees are all heading this way at the moment
0:46:17 > 0:46:19and there's a lot of lime trees over that way.
0:46:19 > 0:46:22And there's less insecticides
0:46:22 > 0:46:25and there's an abundance of pollen and nectar.
0:46:27 > 0:46:30There's a real medley, I suppose,
0:46:30 > 0:46:32as well, with all the different parks
0:46:32 > 0:46:35and avenues and people's gardens as well.
0:46:35 > 0:46:36So, they do incredibly well.
0:46:38 > 0:46:42Evidence from all over the world is showing that urban environments
0:46:42 > 0:46:45are bucking the trend when it comes to the decline in bees.
0:46:46 > 0:46:50In the UK, for instance, honeybees produce more in Birmingham
0:46:50 > 0:46:52than they do in surrounding areas.
0:46:52 > 0:46:55And hives in Paris yield roughly twice as much honey
0:46:55 > 0:46:57as colonies in the French countryside.
0:47:00 > 0:47:03For now, the research seems to suggest that it's the varied diet
0:47:03 > 0:47:07that city bees are getting that may be keeping their numbers up.
0:47:07 > 0:47:11And the evidence of how different habitats affect honey is very clear.
0:47:14 > 0:47:17So, we've got a Wapping honey here from E1,
0:47:17 > 0:47:19and this is quite a toffee-like honey.
0:47:20 > 0:47:22I love that. You've got it all down you, but I love it.
0:47:23 > 0:47:26- This is a good honey. - It's a very good honey, yeah.
0:47:26 > 0:47:29And then this is a honey from the roof of the Tate Modern.
0:47:29 > 0:47:32- Tate Modern?- Yeah.- And Wapping - that's not very far, is it?
0:47:33 > 0:47:35Mm!
0:47:35 > 0:47:38Now, the distance between the hive that produced this
0:47:38 > 0:47:40and the hive that produced that - how far?
0:47:40 > 0:47:42A mile and half, I'd say.
0:47:42 > 0:47:45How is it that you can get such a different variety of honey,
0:47:45 > 0:47:48though, in such a small, short distance?
0:47:48 > 0:47:51In urban areas especially, there's the most, you know,
0:47:51 > 0:47:54fantastic array of flowering plants and trees.
0:47:54 > 0:47:57I couldn't pass up the chance of showing off my own produce.
0:47:57 > 0:48:00- Do you want to try my honey now? - Of course I want to try your honey.
0:48:00 > 0:48:02This is from Buckinghamshire. Deepest...
0:48:02 > 0:48:06Not deepest... It's only just outside the M25, really.
0:48:06 > 0:48:08I love the label. It's like there should be some sort of warning.
0:48:08 > 0:48:11- Could be toxic. - Could be toxic. No, it looks great.
0:48:11 > 0:48:13It's a couple of years old - I didn't get any honey last year.
0:48:13 > 0:48:16- It's a mature...- Mature.- Lovely. - It's been getting better in the jar.
0:48:16 > 0:48:18It hasn't crystallised at all.
0:48:18 > 0:48:22- Oh, now, that's rather good, Bill. - Is it?- That is rather good.
0:48:23 > 0:48:24Really lovely.
0:48:26 > 0:48:29I think Steve's probably being generous.
0:48:32 > 0:48:35This fact that bees are doing well in cities could, of course,
0:48:35 > 0:48:39be hinting at what's happening in the countryside.
0:48:39 > 0:48:43And I'd like to find out a bit more about how that habitat is changing.
0:48:47 > 0:48:49'060 degrees, 11.'
0:48:49 > 0:48:50Thank you.
0:48:50 > 0:48:53Dr Deepa Senapathi has being studying
0:48:53 > 0:48:55the changes in land use in the countryside.
0:48:57 > 0:48:59- Cool. Isn't it cool?- Yes!- I love it.
0:49:02 > 0:49:07'Traffic from 172 operating in the vicinity of Milton Keynes.'
0:49:08 > 0:49:13To demonstrate what she's found, she wants to give me a bird's-eye view.
0:49:14 > 0:49:17So, we're flying over some mixed woodland here,
0:49:17 > 0:49:22which you'd think would be a pretty nice place for bees to live.
0:49:22 > 0:49:23What's the picture been here?
0:49:23 > 0:49:28This site, historically, was woodland, and very little has changed
0:49:28 > 0:49:31and less than 5% of this site has changed over time.
0:49:31 > 0:49:33And yet,
0:49:33 > 0:49:37there's a 35% decline in species richness that's been recorded.
0:49:38 > 0:49:41So, more than a third of the different kinds of bees
0:49:41 > 0:49:45that once lived in this woodland have now disappeared.
0:49:45 > 0:49:46What's intriguing here
0:49:46 > 0:49:49is that their immediate habitat has barely changed.
0:49:51 > 0:49:53What do you think is causing that?
0:49:53 > 0:49:57If the habitat here is friendly enough, what's happened?
0:49:57 > 0:50:01What's happening around the site is really important for bees.
0:50:01 > 0:50:05So, bees could nest within this site, but they might forage
0:50:05 > 0:50:08up to a kilometre or two outside of the site.
0:50:08 > 0:50:11And what is really striking
0:50:11 > 0:50:15is the level of agriculture has gone up by about 30%.
0:50:15 > 0:50:19So, if I were to show you an old map...
0:50:19 > 0:50:24This is what this area used to look like in the 1920s and '30s.
0:50:24 > 0:50:28All the light green bits that you see are meadowland and grassland
0:50:28 > 0:50:32with a little bit of agriculture, which is the brown bits.
0:50:32 > 0:50:35But if you look out of the window now, the entire countryside
0:50:35 > 0:50:40is turned into quite intensive agriculture and farming.
0:50:40 > 0:50:45Deepa's research has been repeated around 23 other sites in the UK
0:50:45 > 0:50:48and they all show the same thing.
0:50:48 > 0:50:50Although this landscape may look greener,
0:50:50 > 0:50:54it's what ecologists call a "green desert".
0:50:54 > 0:50:57Over the years, plants that bees do feed on
0:50:57 > 0:51:01have been replaced by vast expanses of plants that they can't feed on.
0:51:01 > 0:51:04It is quite counterintuitive, because you look at green,
0:51:04 > 0:51:07you look at the swathes of plants you can see there
0:51:07 > 0:51:10and you think that must be really good for bees and pollinators.
0:51:10 > 0:51:14The logical conclusion would be, then, that we need to rethink
0:51:14 > 0:51:17our entire system of modern agriculture,
0:51:17 > 0:51:18of the way we grow things.
0:51:18 > 0:51:21I think it's just a slight shift in, perhaps,
0:51:21 > 0:51:25thinking of more wildlife-friendly farming methods,
0:51:25 > 0:51:28not saying, "Agriculture is bad."
0:51:28 > 0:51:31It's just, there are ways to improve agriculture
0:51:31 > 0:51:35in a way that it might be more useful to biodiversity,
0:51:35 > 0:51:37it might be more friendly.
0:51:39 > 0:51:41So, you won't be surprised to hear that scientists
0:51:41 > 0:51:44aren't simply looking at why are the bees are dying.
0:51:44 > 0:51:47They're also trying to work out what we can do about it.
0:51:58 > 0:52:00One of the first things they've looked at
0:52:00 > 0:52:04is taking place in the grounds of the University of Reading.
0:52:04 > 0:52:07They're hand-pollinating strawberry plants.
0:52:11 > 0:52:14It might seem strange, but hand-pollination is something
0:52:14 > 0:52:17that's already been tried out in southwest China,
0:52:17 > 0:52:21where wild bees have been completely eradicated due to loss of habitat.
0:52:24 > 0:52:27Perhaps it could be an answer for us.
0:52:27 > 0:52:30- Take some pollen from there. - So, here on the outside?- Yeah.
0:52:30 > 0:52:34- These...- These are the anthers that actually produce the pollen.
0:52:34 > 0:52:36- OK. Where shall I go? - Let's try this flower here,
0:52:36 > 0:52:38- so right on the centre. - Right on the centre.
0:52:38 > 0:52:41- That one?- Yep.
0:52:41 > 0:52:43And you dab it on there gently
0:52:43 > 0:52:45and you'll have rubbed some pollen onto the stigmas
0:52:45 > 0:52:48and that will help develop and fertilise
0:52:48 > 0:52:50and you'll start a strawberry.
0:52:50 > 0:52:53I can see straightaway, though, that it's not exactly
0:52:53 > 0:52:57the same intricate talent that a bee would have!
0:52:57 > 0:52:58We're clumsy. We're clumsy.
0:52:59 > 0:53:03What the bees do perfectly is spread the pollen very precisely
0:53:03 > 0:53:06and evenly across the stigma of the flower,
0:53:06 > 0:53:10which is extremely important when it comes to the finished product.
0:53:10 > 0:53:14So, as consumers, what do we like to have?
0:53:14 > 0:53:17We like to have nice, large, perfectly formed fruit,
0:53:17 > 0:53:20that's what we're after, and you need good pollination to get that.
0:53:20 > 0:53:23And here's an example, this is quite an extreme example,
0:53:23 > 0:53:25but this hasn't been pollinated properly.
0:53:25 > 0:53:28- Is that appetizing?- No.- Not really.
0:53:28 > 0:53:31So, given the world where we've got declining pollinators,
0:53:31 > 0:53:34we wanted to ask the question, how much would it cost
0:53:34 > 0:53:36to replace that service that bees are giving?
0:53:36 > 0:53:39So, we trained up some students and we gave them paintbrushes
0:53:39 > 0:53:42and we timed them to pollinate different crops -
0:53:42 > 0:53:44strawberries, apples, oilseed and so on.
0:53:44 > 0:53:45And then we calculated
0:53:45 > 0:53:49how many of those flowers there are flowering in a year in the UK
0:53:49 > 0:53:50and putting that together,
0:53:50 > 0:53:53working out what would be the minimum wage we could pay them.
0:53:53 > 0:53:56We came up with a figure of £1.9 billion a year
0:53:56 > 0:53:58to replace the service that bees do.
0:54:00 > 0:54:03So, it's pretty clear hand-pollination isn't practical
0:54:03 > 0:54:05and we really can't do without bees.
0:54:08 > 0:54:10But there is a second option,
0:54:10 > 0:54:13to find ways of creating a more bee-friendly environment.
0:54:18 > 0:54:21There's another research group at University of Reading
0:54:21 > 0:54:24who are trying a very different approach.
0:54:24 > 0:54:28Scientists Vicky and Jenny Wickens are investigating a way to help bees
0:54:28 > 0:54:33thrive on prime agricultural land without affecting the way we farm.
0:54:35 > 0:54:37So, what have we got here?
0:54:37 > 0:54:41This is a sown flower strip, so these flower strips are put in,
0:54:41 > 0:54:45so they can boost the natural pollinators in the area.
0:54:45 > 0:54:49In fact, with bumblebees, we've found 500% more bumblebees here
0:54:49 > 0:54:53than we do at grassy field margins in comparison.
0:54:54 > 0:54:58They're conducting a trial across 16 different farms.
0:54:58 > 0:55:00And where they planted these flower strips,
0:55:00 > 0:55:04they found the number of solitary bees went up by about a third
0:55:04 > 0:55:06and bumblebees increased fivefold.
0:55:09 > 0:55:12We see what the bees get out of it. What's in it for the farmer?
0:55:12 > 0:55:14They get improved yields.
0:55:14 > 0:55:16We have put potted plants
0:55:16 > 0:55:18in both the flower strips and in the field boundaries,
0:55:18 > 0:55:22so just typical grassy field boundaries, and we are looking at
0:55:22 > 0:55:26the number of seeds that are produced by these potted plants.
0:55:26 > 0:55:29We found a 50% increase in the number of seeds
0:55:29 > 0:55:32in the flower strips rather than the field boundaries,
0:55:32 > 0:55:33and this just proves
0:55:33 > 0:55:36how important these flower strips are to the farmer.
0:55:42 > 0:55:46So, if successful, these flower strips could not only give bees
0:55:46 > 0:55:49a home in the countryside, they could actually increase
0:55:49 > 0:55:51the amount of food farmers can produce
0:55:51 > 0:55:54without changing the way they grow their crops.
0:56:02 > 0:56:05But there's another potential solution in the pipeline
0:56:05 > 0:56:07which, in the long-term,
0:56:07 > 0:56:10could be rather promising, although it is some way off.
0:56:12 > 0:56:15Lin Field is doing something which might make us
0:56:15 > 0:56:18less dependent on traditional pesticides.
0:56:19 > 0:56:22She's creating genetically modified plants
0:56:22 > 0:56:26which she believes could one day replace pesticides
0:56:26 > 0:56:28and help protect our bees.
0:56:30 > 0:56:35Here we're trying to use a natural compound that aphids produce
0:56:35 > 0:56:38to warn other aphids that there's a predator around,
0:56:38 > 0:56:40that there's some sort of risk.
0:56:40 > 0:56:42This compound, which is called (E)-beta-farnesene,
0:56:42 > 0:56:45is a pheromone, an alarm pheromone,
0:56:45 > 0:56:49and it's normally secreted by the aphid and other aphids detect it.
0:56:49 > 0:56:51We can demonstrate to you how it does that,
0:56:51 > 0:56:54so if you take the syringe, which has got the compound in it,
0:56:54 > 0:56:58and I take off this little clip cage so we can see the aphids,
0:56:58 > 0:57:00and you put the drop onto there.
0:57:03 > 0:57:06And what we've done is, we've engineered into a crop plant
0:57:06 > 0:57:08the ability to make this compound,
0:57:08 > 0:57:11so that the plant itself gives off the smell
0:57:11 > 0:57:13and aphids don't attack it.
0:57:13 > 0:57:17- So, it will naturally scare the aphids away?- It will.
0:57:17 > 0:57:20So, the colony that was there, some of them are still there,
0:57:20 > 0:57:22but most of them have moved away.
0:57:22 > 0:57:24They're coming around the edge side of the plant.
0:57:24 > 0:57:26Indeed, a lot of them have dropped off.
0:57:26 > 0:57:31It's using a natural system that the aphid has evolved to detect
0:57:31 > 0:57:33in a situation that will help protect our crops.
0:57:33 > 0:57:35So, what does this mean for the bees?
0:57:35 > 0:57:38The bee will be completely unaffected by this compound.
0:57:38 > 0:57:42The bees don't detect this compound, they wouldn't respond to it,
0:57:42 > 0:57:44so it wouldn't be affecting bees.
0:57:46 > 0:57:49Both these strategies will take years to implement
0:57:49 > 0:57:52but it's hoped they could help reverse the decline in bee numbers.
0:57:57 > 0:57:58So, what is killing our bees?
0:58:01 > 0:58:04These beautiful, complex creatures are ultimately very sensitive
0:58:04 > 0:58:06to any fluctuations in their environment.
0:58:09 > 0:58:11We live in a rapidly changing world
0:58:11 > 0:58:14that they are struggling to cope with.
0:58:17 > 0:58:22Viruses, chemicals and modern agriculture
0:58:22 > 0:58:25form a fatal combination for these fragile insects
0:58:25 > 0:58:27on whom we depend so much.
0:58:28 > 0:58:30What strikes me
0:58:30 > 0:58:33is that there's a common factor behind these three, and that's us.
0:58:33 > 0:58:36We've helped to spread the varroa mite,
0:58:36 > 0:58:37we've developed pesticides,
0:58:37 > 0:58:40we've changed agricultural practices.
0:58:40 > 0:58:45Perhaps it's what we're doing ourselves that's killing the bees.
0:59:11 > 0:59:14Subtitles by Red Bee Media Ltd