To Biodegrade, Or 'rot' To Biodegrade?Researcher Adam Gusse and his colleagues at the University of Wisconsin have found a fungus capable of rotting the previously un-rottable - compounds called phenolic resins (PRs), the plastics used in the trims on car bodies, air filter housings and other heavy-duty automotive parts. They're made by heating phenol and formaldehyde (formalin) to high temperatures in the presence of catalysts which cause the molecules to link together in a three-dimensional lattice that is hard to break. But therein lies their weakness - these compounds, which were previously thought to be non-biodegradable, closely resemble the natural substance lignin, the hard part of wood. Since lignin is a popular food source for fungi, the researchers wondered whether the cocktail of lignin-busting enzymes produced by "white-rot" fungi might also be able to break down these phenolic resins. They incubated cultures of fungi with the plastic and looked for signs of degradation. In tests on 11 fungal isolates they found one strain, called Phanerochaete chryosporium, which was capable of digesting the phenolic resins. Under an electron microscope samples of the resins showed pits where they had been eroded by the fungal digestive juices. This suggests that it might be possible to use this technology to recycle the millions of tons of phenolic resins produced each year instead of dumping them in landfills. 17th Jun 2006 Simply Hair-raisingA study amongst Welsh school children, published in the journal Archives of Disease in Childhood, has found that four out of five headlice are now resistant to treatments, such as permethrin and the organophosate malathion, which are traditionally used to eradicate them. The researchers combed their way through the heads of 300,000 school children from 31 schools. They then tested samples of the lice they collected to measure their resistance to treatment, including the levels of enzymes such as glutathione transferases, mono-oxygenases and esterases. Of 316 lice tested, 80% were resistant to the standard treatments. Healthcare workers in Wales are now presumably scratching their heads as they try to decide what to do about the problem. Although the study was conducted in Wales, the same treatments are used almost universally for headlice, so it's likely that what's true for Wales is going to be true elsewhere too. Thankfully help might be at hand in the form of newer silicone-based lotions, to which the lice are reliably sensitive. 17th Jun 2006 Locust-inspired Car SafetyDr Claire Rind, University of Newcastle-Upon-Tyne
Chris - When we say compound eye, how does the insect actually process the light coming in? It's got loads of images of the world coming in at once. That must take a lot of processing. Claire - It does take a lot of processing but that isn't the way the insect looks at it. They don't have thousands of complete images. Their whole image of the world is pixelated and broken up. Every little lens looks out at a particular region in space and then it just has to put together all the information from that particular region in space. There is some beautifully engineered circuitry and it's repeated many times over the eye. Chris - You actually won an Ignobel Prize for showing episodes of Star Wars to locusts. Why? Claire - Because I could! Chris - Who was funding this research?! Claire - The BBSRC. Star Wars had a huge array of visual scenes and looming motion, and that's why we chose Star Wars. Looming is when an object is coming straight for you, like a spaceship. The other thing is that they have spaceships moving directly over you. They were coming very close but weren't actually having a collision. So we could test the different responses of the neurones to a near collision and a collision. Chris - And this is your locusts' anti-bumping device. Claire - Yes. Chris - How does that actually work? Claire - It detects objects which are approaching and expand over the eye. There are circuits that extract those image cues and will give a warning when the system detects very rapidly expanding edges, which are features of objects approaching on a collision course. Chris - So how could you apply that to the automobile industry, as this is the stance you're taking on this? Claire - The way we're applying this is that we've got a little silicone chip which is inspired by the insect eye and it has small photocells rather like the cells in the insect eye. The signals are passed through various layers of circuitry, and eventually after much computation, the signals are summed up and a collision warning is issued if there is sufficient evidence for there being an object on a collision course. Chris - But how is this better than a driver at the wheel of a car anyway? Or are you thinking now of a car that has autopilot or something? Claire - They could have an autopilot, but at the moment the driver is not very good at reacting quickly enough. This is especially so if a child or something steps out quickly in front of the car and the accident is imminent. Chris - Say a child steps out but there's a child coming the other way. How does your computer resolve that? Claire - The most salient features, or the ones that give the biggest responses , would be the ones the system would react to. Chris - So it would hit the kid and ignore the car coming the other way then. Claire - No it wouldn't hit the child. That would be the image that was expanding most rapidly over the sensor and the collision alerting system would be switched on by that image. It ignores a lot of other movement, like flow fields, or images flowing back over the sensor. It's specifically looking for an object which is on a collision course. The car coming straight for you will be a problem for you as well! June 2006 In Search of Social BeetlesDr William Foster, Department of Zoology, University of Cambridge
Chris - One of your interests is in social animals and you're going to be going out to the back of beyond to Thailand soon. Why is that and what is it you're going to find there? William - We're hoping to look for social behaviour in beetles. Social behaviour in insects is very important because the most successful animals in the world, of all animals, are ants and termites. They're successful because they're social. They're able to have huge colonies and be very well organised. This has evolved rather infrequently; it only appears in ants, bees wasps and termites. We'd like to be able to see whether the largest group of animals in the world, the beetles, whether any of them are social. There's a particular group of beetles there called passalid beetles, and the Americans call them bess beetles. They have quite advanced parental care, that is that the parents look after the young and do things like help the larvae make the pupal case around them. They can't do this themselves and the parents have to push from one side while the larvae push from the other. It's a very elaborate social care. This has been known for a while but no-one has ever studied them very thoroughly. We know there are large colonies of various species in this part of South East Asia and we want to go and find them. Chris - So when you're mounting an expedition like that, how do you set it all up? What are the steps involved and how much is this going to cost? William - It doesn't cost all that much. We're doing it with the Natural History Museum in London and they are mainly going to collect beetles and lepidoptera, butterflies and moths, in the area generally. They've done most of the organisation. What is really required I a permit to bring the material out of Thailand. All countries quite correctly don't like people going in and pillaging all their animals. We haven't yet got the permit and the Natural History Museum are still negotiating with the Thai authorities, but we will have that. Otherwise, you just need somewhere to live, nets, tubes and alcohol. That's 80% alcohol in which to put the insects when we've caught them. Chris - So not for the scientists to drink then? William - No! Chris - So going back to these beetles, do we think that the origin of this social behaviour in ants and wasps, evolved from a common ancestor or have they independently evolved to have this interdependence on each other? William - It's happened independently several times, but not that often. The termites probably had two origins of social behaviour for example, the ants probably only one. Another group that is social are the aphids. You would expect them to be social because they're colonial. They're clonal and all the same genetically. The Portuguese Man of War is also a social animal. It's clonal it's identical and only some of the animals in a Portuguese Man of War that reproduce. Chris - So is that the same in aphids? Rather than just cloning themselves they will actually have sex? William - Well only some of them reproduce. Some of them are totally sterile. Chris - This is green fly, not Portuguese Man of War. William - Yes, this is green fly. Some of them are just warriors, like there are warrior polyps. Chris - Is that to distract predators? If you've got fifty million green flies and a couple of them don't actually do anything except sit there eating and being all fat and juicy, if something comes along to eat the green fly it's more likely to pick on one of the sterile ones. That leaves behind the ones that will reproduce and can foster offspring. William - Well it's more the case that there are soldiers that are heavily armed baby ones that rush around over the colony kicking off parasitic wasps or anything that's trying to eat them. Chris - There was an interesting story recently where scientists were looking at how plants have their own alert system where they use chemical signals. When a caterpillar or a green fly eats the plant, the plant releases various chemicals that actually attracts predators that eat the animals that are eating the plant. William - They don't attract predators but parasitoid wasps. They come flying in and lay their eggs on the caterpillars that are eating the plant. It's a relatively recent discovery but it's definitely true and there's lots of good evidence for this now. Chris - Going back to your Thailand situation, why is it that no-one's ever discovered that there are these social beetles knocking around given the wealth of information you've already told us? These things have this interdependent relationship with each other. They can't reproduce without another's help. William - People have studied them a little bit. Some work has been done in America. An American school teacher in the 1930s kept them by his bed and watched them doing various things. I suppose there's not much money in them and they're not that important ecologically. They are quite important. They live in wood and break down wood. No-one's really been that interested in the theory; the evolution of social behaviour. Chris - Isn't there a claim that in the same way Claire is trying to look at locusts to see if we can borrow from biology to make cars safer, people are interested in how ants communicate and signals are passed through colonies to make computers work faster? William - Yes, indeed. I thin there are lots of analogies one can make with social insect colonies and how to make things like brains and complex systems work. All these colonies work on simple rules that the individuals make. By the accumulation of lots of simple rules and lots of individuals, one can get the emergence of lots of complex properties. Helen - Going back to your expedition, I presume it's rainforest that you're looking at, how will you know if the beetles are social rather than a group of beetles living together in a high concentration? What are the keys that you'll be looking for? William - The key thing we'll want to see in the end, and this will unfortunately mean killing them, is the extent to which the females in particular are reproductive. If we got a hundred beetle sin one log, we'd collect them all and see if there is a queen beetle who is full of eggs, and lots of worker beetles who aren't. So we're looking for the extent to which reproduction is concentrated in one individual rather than being spread evenly across the whole colony. No-one knows that at all for this group at the moment. June 2006 Insect ConservationMatt Shardlow, Conservation Director of BuglifeChris - Tell us a little bit about your work. Matt - We're a little charity called Buglife and we were set up four years ago to fill in the gap in the conservation agenda where there hadn't been an organisation promoting the conservation of all British invertebrates, of which there are 44000. They're incredibly important little animals that do all sorts of jobs like pollinating flowers, keeping wildlife alive, and are the little cogs that keep the world going round. Without them all the other wildlife would be in trouble. We were set up as a new charity to try and deal with some of the conservation issues specific to invertebrates. Chris - You've very kindly offered to give a year's membership to the winner of our competition this evening. What will that entitle them to? Matt - As a member they are part of Buglife and supporting the work that we're doing and making sure that there are some more invertebrates out there. You'll also get some of our updates and posters and access to our website, and so on. Chris - Now one of the things you're looking at are brown field sites; in other words sites that people have built on and become derelict. They're important for these kinds of animals allegedly. Matt - Absolutely. Brownfield sites are actually as important for endangered invertebrates as ancient woodlands. So we think of some of these natural sites as being very natural and very untouched by human hands and being very important for wildlife. Actually, some of the sites that we've been mucking around with are also very important to wildlife. For instance, old sand quarries such as near the Thames Gateway where these sites are close to the sea, you find invertebrates living in these old quarries that would have been found in the salt marshes. Of course the salt marshes are now all covered in sea defences so there's nowhere left for these animals to live. However, these brown field sites have a lot of other features that are important to wildlife and important to invertebrates. Chris - It's quite ironic that we've created an area of human habitation and therefore a niche for these animals, and we might end up having to conserve areas of the countryside that we've initially damaged in order to save these species. Matt - Yes. We tend to think of green fields as being analogous with wildlife rich and wonderful Eden-like things. But if you actually look into what falls into the formal classification of a green field, it also includes brown arable fields that are sprayed repeatedly with pesticides. Most of the pastures out there have very few wild flowers left in them. They're covered in fertilisers, which is bad for the invertebrates, and they're sprayed in pesticides which is bad for the plants and the invertebrates. So in terms of a rich ecosystem, these ecosystems are relatively rare. A lot of these places where there are lots of wild flowers and lots of nectar and pollen sources, there's also lots of bare ground and things to nest in and bask in which lots of these invertebrates love to do. Chris - What sort of animals are we talking about here Matt? Matt - Wasps, beetles, bees, butterflies and things like the Dingy Skipper for instance. Also bumblebees. Bumblebees need these large areas to go and forage and get all their nectar from so they can get the next generation of queens out for the next year. Without these areas of brown field, there would be much smaller nectar resources for a lot of these bees and they'd be going extinct. They're already declining rapidly. Many bees are only hanging on in the Thames Gateway on these large brown field sites that still have wild flowers on them. Helen - They all sound fantastic all these bugs that we can find. What do people who live nearby think of these insects? Are they aware of them or are they hidden away so we don't really see them? Matt - They're becoming more aware of them and that's on eof the reasons that Buglife was set up. Bugs get a lot of bad PR and mosquitoes being out to get you and new invasives being out to destroy the countryside. But no-one's out there saying, look, these bees pollinate our crops. Two out of every three mouthfuls of food we eat is there because of pollination and 80% of the crops that are grown in Europe are pollinated by invertebrates. If we're looking at an environment that's sustainable, we need to protect pollinators. Who knows what we're going to be growing in a hundred or two hundred years time? We need to be able to feed our children and grandchildren. June 2006
Catching Insects with Pitfall TrapsSet a pitfall trap for some of the wild animals in your garden, using just an old plastic cup, and investigate the fascinating world of bugs. What you needA plastic cup A small trowel (something to make a small hole) Somewhere to put the hole - eg a garden. Half a bucket / Ice cream container (optional) What to DoAll you need are some plastic cups and you need to find a patch in your garden where you can safely dig. Don't dig up the middle of your lawn or anything like that. Just dig a small hole in a flowerbed or under a bush. Put the cup in and make sure the surface of it is completely flat with the soil, so that any insects walking along can easily walk into it. What you could also do is put half a bucket over the top of it to protect it from the rain and the sun. Then leave the trap for a few hours, maybe overnight, come back and see what little monsters you have caught. What may HappenSam found a springtail - They've got six legs but they're not actually insects. They're called non-insect hexapods. They look as though they're about 3 or 4 millimetres long. They crawling around like ants but with longer antennae. They have a spring at the end of their tails, which is a little structure that looks a bit like an arm. They can straighten it very fast and will propel them into the air, so it's an escape response. The reason is that these things are eaten by nearly everything, so that's why they're a bit nervous and twitchy animals. Everything's trying to munch them. Luke Caught a pill woodlouse. Its response is to curl up a little bit like an armadillo and protect itself from predators.
What is going on?You may find that traps in dark shady places work a lot better than in the sun, as insects feel a lot safer from big predators like birds. If you want to identify the bugs you find you could try: Kendall Bioresearch's Insect Key
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