Skip to main content

tv   Doc Film  Deutsche Welle  April 20, 2019 10:15am-11:00am CEST

10:15 am
stories we're following for you in northern ireland police have arrested two teenagers in connection with the murder of a young journalist on thursday they are on the case was hit by a bullet actually covered a riot in the city of london during the violence erupted after officers searched the home and the area. you're watching news live from berlin up next a documentary about the consequences of the world the minissha insect population and searching. stand for. language courses. video. anytime anywhere.
10:16 am
there's a mighty drama going on right in front of our eyes and insects are dying on maps and there's no end in sight. we're losing the identity of our planet because she does and to minutes it's off yet but it is five to. man is exploiting the earth and penetrating to its farthest reaches regardless of the harm he is doing. good for i have to go home buying cuts i used to have an ice scraper in my car to get through when shit loads of this fall like you just told me that in sex play a crucial role in life on earth what would happen without them. we must assume that in time ecosystems will collapse steamer columbia.
10:17 am
insects are at the very start of our food chain but their numbers are dwindling fast and that is in danger in the entire terrestrial life cycle and man is the cause as he has been for decades. but from our teams dog and his comrades in arms from the entomological association in clapham it's nothing new. as a listener and as it is in fact we've recognized and publicized the development of species decline in insects for a long time outside the continent first inflation is in the us and then walking this you can see it in the red lists. no matter which country you take. you have the strong trends in species decline in certain regions everywhere like. the cuts out scientists wanted to find out how dramatic this decline really is and
10:18 am
started by reevaluating their long term observations. hines fun has been measuring the incidence of flying insects for decades often at the same locations he always uses the same special trap as was on the is that what's special about these traps is that we've been putting them in a stack of buildings since the eighty's always facing some us you know all squishy lawsuit every insect that comes up against this black screen recognizes it as an obstacle ok and then oriented south towards the light and cause points club and the whole. the quest though team's containers hold a scientific treasure which is now being mined piece by piece there surveys form the basis for current inventories worldwide. this type of insect travel allows us to capture a much broader section of biodiversity of flying insects. on this we've been doing
10:19 am
it in this standardized form for such a long time and can now compare every new location in every new research project with its entire series because the complete sample materials are available in archives supporting months they are in. for the act. their measurements are so valuable because they are the only ones to have monitored insect populations using the same procedures for over thirty years. but only now has a detailed comparison of the data showing the dramatic extent of insect decline in . the main trunk and you have the amounts vary from year to year you notice that but overall the number is dropping quickly and you can't miss it as you can see that from the samples and we can represent it using the weighted results as a basis. it.
10:20 am
isn't to zero two samples from the same site one was taken off to fourteen days in one thousand nine hundred. and the other after fourteen days in twenty sixteen. stunt so it sort of all in session. the change is obvious insect populations have declined by up to seventy five percent over the past twenty seven years every species group has been affected pollinators scavengers and carnivores. nobody knows how many species have disappeared completely. but the alarming scale of insect mortality has shaken experts around the world and. certainly the scientific world was horrified to see the report that insect populations had declined so
10:21 am
dramatically you know down by three quarters in some areas and this is shocking this is truly shocking because insects are the you know of course there are the. close to the bottom of the food chain of of life. but there also most of the animal diversity of the planet and a tradition says this is actually quite fatal because the decline in insects indicates that something is changing dramatically in our environment. and we humans are part of that environment via mentions and sometimes we forget that. but let's just say i think the situation is very serious and we're not talking about the sixth extinction or nothing when you're almost as soon as we're facing some irreversible changes when species disappear they cannot be resurrected. has man underestimated the value of insects just because they're so small. they're pollination is the only thing that allows many plants to germinate the very
10:22 am
survival of many plants fruits and vegetables is threatened by the disappearance of the insects that flying from flower to flower in search of food butterflies are among them. really. butterfly experts detlef colleagues sees this mass mortality in our environment at first hand during his regular nightly rambles through the forests. he's counting moths using wine mixed with sugar to attract species that do not react to light onto the tree bark. others follow the beam of light and land in his net. but men are not who he was standing here in the middle of a nature reserve in a forest with he fled and that has developed close to nature in an extremely
10:23 am
species rich habitat it's a warm evening in mid august so the screen should be covered in insects so we ought to expect about two or three hundred butterflies so it's really scary how few there are this year honestly and flea. markets form the largest group but the light and colleagues wine and sugar mixture on the bark of the trees today attract virtually none at all. they are just rippling. they're no longer even present. in general they are as highly endangered as most in six pieces. the number of species and the number of individual insects has declined especially over the last twenty years of. his observations are included in the red lists of endangered species. one reason
10:24 am
for the decline is the lights in our cities. question for an a list for by that we mean like pollution lighting is now only present at least in our society and which the torch that i'm using has a mixed light bulb and we also use mercury vapor labs for these are actually the standard wide spectrum street light sources particularly in the short wing for range and that attracts many nocturnal insects and seem to feed a lot of them. but light pollution alone is not to blame for the dramatic decline. and i'm sorry there is no one single factor that influences everything the diversity of interrelationships between the various sources of threat that accounts for the massive decline. of the masses in the uk and all. animal species are dying out before man has even comprehend it what they actually
10:25 am
do interludes behavioral scientists are trying to find out how bumble bees find their way around and what that means for their survival. much yearly overalls team has bred their own bumble bee colony for their experiments. the bumble bees are free roaming but the colonies collectors often take identical fly past. the bees apparently communicate with each other. but what criteria do they use to select their routes. are bumblebees even able to estimate and memorize distances. what we're trying to understand is how bumble bees develop their roots between flowers in a natural environment in fact what we do is follow the bumblebees visits to the flowers with a motion detection camera system and as you can see we have several specially prepared artificial flowers in his tent by analyzing all the video clips from the different webcams we can trace the bumblebees individual trajectories.
10:26 am
to match the videos of the flight routes. the individual insects the researchers mock the bumblebees backs placing the numbers in such a way as to not disturb them. because we want to understand how the hives forages the lungs you go to get food choose where to go and farm and how much they know the different locations the different flowers whether they somehow optimize their journey to visit all these flowers and then return to the hive on. plastic boxes with blue and yellow leds are used to imitate the flowers. the blue leds are sprinkled with water and the yellow ones with the sugar mixture. this makes them an attractive source of food for the forgers. the researchers repeat the experiment several times varying the locations and number of flowers.
10:27 am
before the experiment they measure which route from the hive to the flowers is the shortest. with character to play with his experiments we've been able to demonstrate that bumble bees and honey bees are able to optimize the path between a small number of artificial flowers between five and ten of them by trial and error these individual beings will be able to find the shortest route to reach all the flowers and then return. of course. we find it fascinating because calculating a route like that is very complex mathematically. huge complex. the smallest disturbances can throw the bumblebees complex orientation system completely out of kilter. so what irritates them most. secure the border is that we know that bees exposed to certain doses of sabah
10:28 am
lethal i.e. non-fatal pesticides can become. disoriented if that happens it stops them finding their optimal foraging routes and they tend to bring less food back to the hive. which i couldn't see in the morning that means less food for the colony which could snowball and lead to a sudden decline in which they could. i agricultural pesticides are thought to be the main culprits. france has already banned five pesticides containing naomi could do noids but are pesticides really responsible for the massive death of bees and bumblebees. harms him or scott's and his team from holland want to know more about this and are running different tests using products farmers actually use against wheat not insects. they are carrying out tests on roundup a week killer widely used in agriculture. it's manufacturers claim neither roundup
10:29 am
nor glide for state in general is talks or. the researchers are looking at whether the substances influence the bees heartbeat. they're starting with a laboratory experiment where the heart function of the bee is maintained at a constant level. leave that have had no contact with life for say have a heart beat of about two hundred twenty to two hundred forty beats per minute. but the heart rate of bees that have been in contact with roundup drops by eighty percent after about ten minutes to about fifty heart beats per minute. are going so. it takes around an hour for it to return to normal. and. fia come to us we found that round up i'm glad if a state reduced the beans heart rates have as up as it can be no. disguise.
10:30 am
state weakens it that means when the heart beats in the living to be slowed there is less oxygen available to the brain and other organs that go through to. cops then investigates the influence of life is a uncontaminated bs the results are clear. ten to fifteen minutes after the bees have received a state concentration equivalent to that in fields their heart rate drops by twenty to thirty percent. you. need a lot of that i didn't actually expect these effects because i'm glad to say it is not very toxic so it doesn't kill the bee and i had actually assumed it was a substance that was only supposed to work on plants and didn't play a role in insects so wide rather assumed that i wouldn't find anything which would have been reassuring. the. what consequences does this
10:31 am
anaesthesia is half for honeybees that end up in a glyphosate treated field in search of food. in a comparative test team again feed the yellow label b.s. with that life is a mixture. in fact the effects of chemical zombies have already been proven several times in comparable tests. as far as honeybees are concerned the texan products certainly do have an effect they weaken them but other factors also play a crucial part but as far as wild bees are concerned i would say that weed killer certainly play a decisive role for. the testers trying to prove the glaive a safe irritates the bees when they return to their own colony. a control group marked with white has been given a water sugar mixture that resembles plant nectar. both groups of bees are released
10:32 am
simultaneously. the bees normal reaction is to fly out orientate themselves and then fly back to the hive which the white ones do. they return immediately. the yellow ones on average take much longer and some even fall by the wayside. toxic substances put solitary bees at risk of losing their brood. seems like a contest which i was up to for b. colonies can withstand this sort of destruction of the two but if other insects become disoriented then of course it could have fatal consequences of alpha that was a photog. interest. in chemicals disturb stun or kill our insects. they influence their behavior prevent them from finding their own hives and starve their brutes to death. or hamper them in their
10:33 am
search for a partner so they don't even produce offspring in the first place. either way the consequences are clear there are fewer and sex. union continuing any. pesticides aren't the only things threatening the survival of beans and also beetles dragonflies and hover flies. biologist teo chandrika is examining colonies of bumblebees. by weighing their hives you can tell how they are developing. effect line for she knew if it works here we compare different environments where bumble bees are so much for example places of a very poor resources with places that are very rich and then we see what the difference is when the intervening vidoe interstate is.
10:34 am
one of the things his studies have shown is that the spread of agricultural deserts huge fields completely lacking in flowering strips are damaging the reproductive cycles of both bumble bees and other wild beasts. less nectar means less nourishment for their own offspring let alone new queen bees. mean you elite in the least. charkha thinks clearing the green strips is as harmful as using chemical pesticides. until recently most people probably didn't even realize that the mortality doesn't only affect honeybees but about five hundred sixty species of while the beans which are really the crucial group they are simply dying out and that's leading to disaster and it turns out that the wild bees are especially important because they
10:35 am
are much more effective pollinators than honey so only creating. a new speech the child is a ph d. student. she wants to prove that wild bees are of much greater importance for fruit and vegetable production that has previously been assumed she compares the flowers of beans and tomatoes pollinated under different conditions and with and without using bumble bees. in many greenhouses tomatoes have long since been manually pollinated. yeah here we've put some of the tomato blossoms into bags to test how the fruits develop with pollination and to test. it as. we compare the flowers on the rest of the plant with those the bumble bees can't get at to see whether it makes a difference we've already done this with strawberries where we've noticed big
10:36 am
differences we only got the big red strawberries we love so much when pollinators were present. and you know. as far as honey bees are concerned researchers have long known what is affecting them and how to protect them. with the wine will be is on the other hand they know much less. has launched a huge field trial he wants to know if wild bees fare better integrate fields. has continued as if there is some evidence that it is also very important for beings not only to absorb the pollen from one species to reproduce but for many important . dr klaus félix has sown break on half of each plot giving the other half over to various other plants. the experiment is intended to show whether different plants influence the wild bees reproductive capacities mission to sit on for i'm especially interested in what kind of pollen was actually collected. you
10:37 am
can see under the microscope which plant the pollen comes from on i'm taking a small sample so as not to influence the bees development but which will still allow me to determine which plants they actually collected the pollen from important is going towards. most wild bees are solitary the females lay their eggs in caves building a parcel for each one where they also store pollens as food for their offspring. with wild bees lose their orientation during the egg laying period the offspring die. even the disappearance of insects whose usefulness has long been recognized has been ignored butterfly researchers have regularly sounded the alarm when a species disappeared but that was really all. nobody cared about more in conspicuous insects. man simply refused to take them seriously and drove
10:38 am
them out of the environment. insects are seen as pests. or or then you have the butterflies which are beautiful but people think that they are not necessary. some because they don't. directly. and many insects are nuisances we have mosquitoes biting a sort of last stinging us and we don't like that so we want to get rid of them. so . insects tend to be. vilified in a way which is which is not a good thing surely the phenomenon is much better understood in mammals and birds and groups that are well known in. butterflies but broadly across all of insects people haven't been looking at it with that sort of focus and there's so
10:39 am
many species that way don't really understand all of the roles that insect species have in our violence but if those species disappear then so long as roles and i will have impacts on the systems that we often can't predict very well. insects might not have much of a lobby but they do a lot of nature's dirty work recycling carrion for example this roebuck has already been dead for two days yet it's teeming with new life tens of thousands of fly larvae are finding their way through its body. beetles also lay eggs in the carcass . it's the cycle of life and without insects it breaks down. mother fly expert detlef colics is keeping a close watch on the markets and his house. every morning he checks which species have been moving around his property the previous night. the variety and
10:40 am
color of the mosque only becomes clear in daylight. forms and richness of color inspired me again and again i guess you always have to bear in mind that the ones we call butterflies really only make up a small percentage of moths as a whole drama. as you put into place which hosting we have about two thousand two hundred species of mouth and only sixty of them about to flies is this incredible abundance of species really excites me. a postal. many mosques are true masters of camouflage. the buff tip for example usually spends the day on birch trunks. but even the best camouflage is useless against an omnipotent opponent such as man. that live colics is working on a project that could be
10:41 am
a first step against the progressive decline of insects breeding a species of butterfly for the not too shoots foundation in his aviary. communalism england and we're looking at the marsh or greasy fertility and fertility rates our number the species that represents many other rare animals and plants in scenes that are in danger of extinction with some reason with the for tillery recovers in its habitat the other species will also do well in. the fertility had already disappeared in the north of germany now the project has reintroduced the plants it needs in just seven areas fertility is lay their eggs on the undersides of the leaves of the devil's bit scabious also known as bitter lettuce the plant also later serves as food for its caterpillars. as they say hope is the last thing to die which is why we are so committed to this project we think it's worth it because we think we can do something but a very great effort is now necessary in particular changes in nature conservation
10:42 am
and especially in agricultural policies politics. the summers in florida on only warm but also extremely well this is why some insect species in miami are defying the trend and flourishing. for mosquitoes the conditions are ideal philip started is a biologist and district mayor in miami. he has developed strategies in the fight against mosquitoes that will also protect the environment he believes education is the key about mosquito larvae in garden plants for example. people love these plants they're easy to grow their beautiful they've got nice flowers they're a complete nuisance. people make their own problems and you put these in your yard because you like them and you say turns a lot of mosquitoes around here nobody has a clue that they're breeding the mosquitoes. since an outbreak of the zico virus in two thousand and sixteen miami has been spraying insecticides in the city almost
10:43 am
every summer night. star doesn't think a lot of the idea he fears the chemical agents will more likely lead to a further spread of diseases. like mosquitoes for instance seem to be doing just fine despite all of our attempts at killing them. and there's some interesting reasons for this. mosquitoes breed very very fast they can go from egg to egg and in eleven days that means they can get in twenty generations a year in miami they can outbreed anybody or anything and they also have evolved resistance to our insecticide. started regularly examines the mosquitoes that have been caught in the two traps in his own garden. he wants to know as early as possible whether the disease carriers are reproducing or whether new species are appearing female and. both would be cause for alarm.
10:44 am
male and. the mosquitoes so for instance the zico as an example yellow fever chicken. those are diseases that evolved in the tropical forests with the forest mosquitoes the forest mosquitoes that evolved. to move into the villages and they brought the forest viruses with. is relying on the mosquitoes natural enemies he thinks the fight against them should begin as early as possible when they're still in the age. when they're in the water they're easy prey for some animals. control mosquitofish. one of the problems we have is that mosquito predators are vulnerable to the same insecticides and i look over here in my yard
10:45 am
and i've got some examples i see two species of dragonflies right now and. one spider species neither of them are resistant to insecticides so if somebody were to come over and spray this yard to kill the mosquitoes they would kill my spiders and they would kill my dragonflies my two natural controls now here's the problem the mosquitoes will be back at their former numbers in two days. i want to see the dragon flies and spiders back for a long time. the realm of the insects is a constant interplay between herbivores and their predators. because species often spreads rapidly and then we call it the plague. but long term observations show this interplay of parasite and predator does work.
10:46 am
but now man's intervention is creating a dangerous imbalance. gets its input it's a politicians need to think about the whole topic of landscape management the planting hedges for example for communities of insects and birds and there must also be international laws to stem the decline that is happening once on a new lease on this was the missing yeah we have to learn to be more careful with our landscape and our environment if so how to use fertilizers whether synthetical organic material and how to use pesticides. we have to be much more cautious and much more aware of what we really need to guarantee our food supply and what we don't need from mine and you know physician well behaved we have to change a lot of things in the way we live. which which is a very difficult thing for us to do so i don't know whether whether we can do
10:47 am
anything quickly which would which would stop the mass mortality but. but we should do a lot. of agriculture that is only about increasing yields leaves many scars intensive fertilization means that plants that need nutrients for soils just disappear and once they are gone the insects that live off them go to. because masses of animals in factory farming need more and more fodder meadows are also now mon more than once. that's why plants are disappearing. a group of insect researchers in western germany is now looking for genuine survival artists. in this case we're looking for these two types of large blue pants of lines this is the dusky blue here and this is the so-called scarce one with a second daughters we are looking at them because they're quite good indicators for
10:48 am
the protection of. these two species i mean looking for this plant. where they lay the eggs. or. you'll lose a tillis team is now collecting flowers. if butterflies live here caterpillars will soon emerge the larvae spin the winners in ants nests and only leave them after pea patient is complete. you also said le has spent the last twenty years looking for the large blues. some areas are no longer used for agriculture but the butterflies have still disappeared. it's obvious that leaving areas to regenerate themselves won't preserve insect diversity on its own. as for these typical species see leaving meadows found is the same as using them. it's utilization system so sooner or later it has to be utilized it needs mowing
10:49 am
and if a mowing and foresting stops and at some point the species will just disappear. zeta low is chairman of the world biodiversity council he has initiated a range of studies aimed at drawing attention to the consequences of the worldwide insect mortality he thinks humans must realise how important insects are. we have calculated that pollinators create value worth one hundred fifty billion euros at world market prices each year in the form of fruit that depends on pollination that means we can actually publicize a number that shows how valuable nature is to us and how important it is to preserve what. one hundred fifty billion euros is the monetary value of the food that only the pollinators can create for us humans. but as far as most insect species are concerned we haven't yet realized how beneficial
10:50 am
they are to our ecosystems it's impossible to put a figure on it. and bad luck shit west of hull in eastern germany a new research project has been launched to publicize the importance of insects for our lives nico eisenhauer is its head he recreates parts of nature in glass cases. the scientists run through future scenarios and show how ecosystems change when some plants or insect species are missing. they are trying to understand the potential consequences of insect mortality. we have here i know about and this is an experiment where we don't have any insects you can see lush vegetation and and you can see red clover which grows very well here so what's next after an insider i'm here i know the one on the other side mainly herbivores dominates this experiment and there's clearly straight to talk
10:51 am
but you take victor through and i want to confess and have seen far and above all the predators are missing they control plant pests it's these predators that are in fact most affected by insect mortality and we're looking at a relatively realistic scenario here that is just sitting out with us from history and. more herbivores but fewer insects overall if this trend continues it could lead to great plagues worldwide. and some glass boxes contain pollinators but hardly flowering plants and others researchers are investigating how many competitors are needed to stop a fence from spreading. in addition the scientists also want to look at the functions of insects and ecosystems as a whole. does
10:52 am
the absence of insects also affect our soil and groundwater. the first clues have come from lady birds. these moving kids these lady birds have eaten the eight so the a feeds have eaten less plants and these changes in the plants have caused changes in the soil and that we have seen significant shifts in soils nets so ladybirds above ground have changed the communities under it. the mixture of the excrement and dead insects can therefore be seen in the soil the more varied they are the more nutrients they leave. pollinators exploiters more predators every insect has its function in our cycle of life. we don't even know about many of them yet. how can their services be replaced by human agency or by machines we can't stop insect mortality but will we even be
10:53 am
able to keep our ecosystems alive without them. no way no way they are optimized in such a way by evolution that it's very hard to replace them. and so it is very hard to imagine a future where the ecosystem services could be replaced by humans or robots or some other far fetched scheme. i think if in fact mortality continues at the rate it is now in time ecosystems will collapse the stun guns steam a colombian they do so much so much that we don't even know what they do that we don't understand properly so if we don't even know what they're doing to keep our society is going how can we even think about replacing them. insects or at the beginning of our food chain frogs and many other amphibians fish small
10:54 am
mammals and birds all live from them exclusively ornithologists have been observing the consequences of their extinction since the one nine hundred eighty s. just as more and more birds are disappearing from the forests and meadows and now from our gardens to. insects are the most diverse creatures on earth so far we can only estimate how many there really are and how many there once were but one thing is certain it's not just the total number of insects that will decrease many species have already become extinct. the scientific results are clear only immediate action to prevent the collapse of our ecosystems. i think it's critically important that we take advantage of what we've learned and apply it you know apply it towards preserving the diversity of life and of course that extends well beyond insects what helps and
10:55 am
sex is typically of great benefit to the remainder of the diversity of life so i am very hopeful and the next and decades the next few decades i think will hold really very strong indication of the future of the diversity of life what we do in these next few decades really. it's going to be critically important. it isn't a minute to twelve yet but it is five two and if any measures are going to be taken then of course the politicians have to do it because the people themselves can do a lot they can do something on a small scale but on a large scale it is a matter for the politicians and those who control the economy. less chemistry less development environmental protection and the conservation and creation of natural habitats are the solutions that would help insects survive.
10:56 am
for the butterfly expert deadlift colleagues a dramatic season is drawing to a close the extremely hot summer has wrought havoc with many butterfly species. the extent to which this will exacerbate the situation in the long term will only become apparent next year. but his attempts to breed golden butterflies one affected by the long drive period. at the end of summer the caterpillars gather on the leaves of their plant pot or the bitter lettuce. they spin themselves into cocoons to protect themselves from predators. because i'm satisfied first of all this is the next generation now it depends on how they survive the winter that's always the most crucial phase and we can't do much and next year they will also isolate themselves and go through another big
10:57 am
growth phase before they paid at the end of april name then at the end of may the butterfly will emerge and the midas motivational. nature conservationists have invested more than three million euros and worked in various areas for years to get go. and butterflies a good shot of survival here again. colleagues takes his caterpillars to a nature reserve on the border with denmark. called in and hunting sadness can live on that is particularly important in today's climate change because we know that biodiversity this big term is also crucial to the stability of ecosystems. long as we live at the time when the weather is changing drastically when we are facing new challenges in the future biodiversity which is actually the treasure of the earth is both the heritage and the future of mankind. to diminish. the scientific evidence is clear
10:58 am
insects can no longer be underestimated. they are the latest fashion in chocolate easter eggs part of a special easter collection created by computer center by tom was called. to his concept this year in what could. modeled on designs by great meanings in fashion makes clear that easter creations. thirteen are.
10:59 am
going to one official estimates more than one point two million venezuelans live in colombia legally and illegally. already uncle walter was returned to. to visit friends you saw i don't think i'd ever go back there to live you know what i live there again i don't know so i'm not sure. witness global news that matters to make phone lines six make. raring to reach. if there is any carotid artery number you have to find it between the lines. literature hundred german streets.
11:00 am
playing . the d w news life from berlin police in northern ireland arrest two men in connection with the murder of a young journalist lira mccain with hit by a bullet as she covered a riot and londonderry on thursday evening her death came on the eve of the twenty first anniversary of the signing of the good friday peace deal police have called her killing an act of terrorism also coming up. in egypt polling stations have opened in a referendum on constitutional amendments that would enable president popped off the top.


info Stream Only

Uploaded by TV Archive on