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So it is 6:14 on a Monday morning - though, for me, it was really an hour earlier still because I am heading into Hamburg, Germany, to record for the final episode of the BBC Radio 4 series 'Who's the Pest?'. I am tired; the problem for me with getting up early is that - paradoxically - I don't sleep  well due to worrying that I will oversleep.

 

So I had some coffee ... but I was sure that none of that had to do with the general slightly crazy mood I was in. Instead I am sure that it had everything to do with the prospect of being suspended from the ceiling by technology that mimics fly feet! And it is to that end, that I am sitting on a very smooth and quiet train, looking out at the snow, and heading to meet Professor Stanislav Gorb, the inventor of the most amazing pieces of biomimicry.

 

Biomimicry is the study and application of biological organisms and adapting their effects for our own uses. We see a lot of natural mimics - to appear more dangerous to predators than they actually are, hoverflies use protective mimicry to look like bees and wasps, while spiders mimic ants to enable them predate on them (aggressive mimicry).

 

As a species we have long been interested in mimicry and have been trying to copy the natural world for our own benefit for thousands of years. We study and adapt insect gait in our robots (oh how we can learn from the mighty cockroach for this); we mimic the pheromones of moths to lure pests to traps and we copy their egg-laying abilities to make better hypodermic needles (needles that are so small as to not cause any reaction and ones that can actually bend out of the way of objects so as not to damage any of our vital organs) - all very funky stuff.

 

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Protective mimicry in action (taken from wikipedia):  'Two wasp species and four imperfect and palatable mimics. (A) Dolichovespula media; (B) Polistes spec.; (C) Eupeodes spec.; (D) Syrphus spec; (E) Helophilus pendulus; (F) Clytus arietes (all species European).
Of note, species C–F have no clear resemblance to any wasp species [THIS IS WHAT WIKI SAYS!]. The three hoverfly species differ in the shape of their wings and body, length of antennae, flight behaviour, and striping pattern from European wasps. One fly species (E) even has longitudinal stripes, which wasps typically don't. The harmless wasp beetle does not normally display wings, and its legs do not resemble those of any wasps.'

 

... But, right now, I want to talk about why I had been suspended from a ceiling in Germany like a one-armed orang-utan.

 

So we were ushered into a very high-ceilinged office and introduced to Stanislav and made to feel welcome. Gorb has three main interests when it comes to insects: plant-animal interactions; functional morphology and biomechanics; and biological attachment. It is this final area of research we will concentrate on today.

 

We have been using adhesives for an awfully long time. Archaeologists have discovered pots that have been held together by sap that are 4,000 years old. Scotch tape, as it is known comercially, was invented by Richard Drew in 1930 and we have been relying on it - and its relatives - ever since. But eventually it ceases to work; the glue dries out or it rots away, leaving a residue when you unpeel it from the binding surface.

 

Stanislav has been pondering these very problems for over 10 years - but through an entomologist’s insight. And a novel solution came from a slightly sensitive situation that a male beetle often finds himself in. Examine this photograph of some very down-and-dirty beetle porn.

 

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Steamy beetle action
© nutmeg66/flickr

 

I once worked on the heather beetle, Lochmaea suturalis, at the then Institute of Terrestrial Ecology, ITE, (now the Centre for Ecology and Hydrology, CEH) in Dorset. It was an amazing time and I had quite a collection of beetle porn (although I was more fascinated when a beetle was parasitised by the Tachinid fly, Medina collaris, and I used to spend my lunch times eating sandwiches and watching maggots crawling out of their bums only for them to decide to crawl back in again ...).

 

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What a beautiful fly... Medina collaris
Used with permission, © Hakon Haraldseide

 

I digress … throughout the mating process, the male beetles have to cling on with utter tenacity while the female carries on her daily business. Not much will put a woman off her food … even in this situation! So how does he mange to do this? We know of many animals that have an amazing ability to climb up walls, with geckos being the obvious ones. But Stanislav looked at what was happening on the beetles' feet (or tarsal segments) as they are known.

 

Here is a leg of a beetle:

 

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Now, their tarsal segments can be hairy – really, really hairy.

 

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This is an image from one of Stanislav's papers on the subject. Check out the mass of setae (the hair-like projections).

 

At the end of the setae are structures that range in shape from spatula shapes to mushrooms. So from the naturally occurring shapes Gorb, with the help of a development company, constructed some synthetic tape (called PVS in the image below). Here is a lovely piece on him explaining how the tape works.

 

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(a) Scanning electron micrographs showing the mushroom-shaped setae in an attachment pad of a male beetle, Gastrophysa viridula, (b) biologically inspired mushroom-shaped microstructured PVS sample, (c) and the surface of the control PVS sample.

 

 

So now we have the tape ... how does this relate to me? Well this is how, with very little dignity, I am able to dangle from the ceiling - much to the amusement of everyone else in the room:

 

First time up, I fell off the ceiling! But this was because there was a screw loose, so the tape did not bind evenly. With the screw sorted, I was back up there again, holding onto a handle attached to a piece of tape that had just been shoved on to the suspended glass square. One-handed! Nearly wrenched my socket out but amazingly the tape held.

 

Just for the amusement of my producer I then repeated this several more times so she could record the right level of grunting! It’s not all glamour you know! However, it was amazing to see the application of taking a really small natural structure and using it for our benefit. We can use this tape for many different things, including mechanised arms that move around very delicate and clean surfaces such as those of mobile phones. No more smudges. And what is also fantastic about this tape is that it can be reused! Marvellous.

 

And I now have a small piece and am amusing myself in my flat sticking various objects to the wall ...

 

Listen to Who's the Pest? on BBC Radio 4

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This blog article comes with a warning - for some reason my tolerance for what some may describe as revolting and distasteful seems to be very high. In fact I view those subjects that most people feel squeamish about as truly interesting - I think that nature is ingenious! So, in light of that forewarining, I will proceed…

 

I think that we are all aware that insects are great ... really great, attractive, adaptive, specialised little packages of wonder. And one thing that we should be ever so thankful for is that an awfully large number of them are decomposers. That is, they break down bodies ranging from large corpses to fallen leaves. And it’s not just the dead bodies that they break down - thankfully they remove waste too - so, think about a world without insects where we would be knee-high in faeces.

 

Many adult insects have developed novel ways to ensure that they are ready and waiting for fresh dung. Instead of locating freshly deposited material (I hope that you are not eating at the moment …), many species of beetle cling on to the ‘host’ and wait for them to defecate so that they can then fall off alongside their food. Check out the photo below with a family group (see doesn’t that sound cute!) of beetles clinging on to a monkey's nether region!

 

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If you think this is extreme spare a thought for the poor dung beetle that hangs onto the backside of a kangaroo...
(Taken from Jacobs et al, 2008)

 

 

 

Sometimes insects take this life cycle a little too far even for me!

 

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(From Encyclopedia of Entomology by John L. Capinera)

 

 

But let's get back to the main emphasis of the blog: flies and beetles are exceptionally valuable decomposers. The decomposing of animal and plant material is essential to ensure that there is a flow of nutrients round our ecosystems. When it’s not waste products, it's dead bodies. And that is what I want to concentrate on here today - what the flies do and how we can utilise this. Can you even begin to imagine what it would be like if there were not flies to break down the bodies of all shapes and sizes that would be littered around?

 

For the second episode of BBC Radio 4's Who's the Pest? I interviewed forensic entomologist Dr Martin Hall (aka Maggot Man), who works with me here at the Museum. 

 

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Maggot Man, Martin Hall, taking his work with flies very seriously! 

 

He’s a brilliant man and he is not alone in working on insects (specifically flies) and their use in forensic entomology. In the department there used to be Maggot Boy - but sadly his postdoc has come to an end - and there is also Amoret Whittiker (not Maggot Girl!). Amoret has recently been the star of the Radio four program The Life Scientific and if you think that I have some strange quirks ... She has also been described thanks to her work on forensic entomology as a Superhero of Science - something to aim for!

 

The maggot is a common name for the larval stage of the fly and is generally associated with the more advanced flies, such as the houseflies and blow flies. In his fantastic books called the Natural History of Flies, Harold Oldroyd described maggots as precocious because they emerged earlier from the eggs in comparison to most insects, and are more plastic in terms of their structure. This feature has enabled maggots to get into and survive in an enourmous range of habitats.

 

The field that Martin and Amoret work in, amongst others, is that of forensics and this has become oh so popular since the advent of TV series such as CSI and Prime Suspect, but the use of insects to help determine the time of death is not a recent phenomenon. At the Museum we have a famous jar of maggots (not often I get to put that into a sentence) that was a sample from the first successful use of insects to tie a murderer to a victim! This story begins with Dr Buck Ruxton, who was a practising GP in Lancashire in the 1930's and was generally well-liked and respected within the community within which he lived and worked:

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The rather dapper Dr Ruxton

 

Then, in September 1935, the bodies of his wife and maid turned up in small ravine miles away in Dumfriesshire, Scotland. He claimed that his maid had fallen pregnant and that his wife had run away with her to assist with an abortion so it couldn't have been him that killed them, guvnor. However, he was a sloppy man! Although their bodies were chopped up to make it more difficult to identify them, there were maggots still associated with the limbs and these were aged by Dr A.G. Mearns.

 

This provided a vital clue as to when the murders took place and it was this, coupled with the damning evidence that one of the newspapers used to wrap body parts was only found in Dr Ruxton's local region and not where the bodies were found, that led to the 'good' Doctor being found guilty and subsequently hanged.

 

So, you can see why they are precious maggots to us! For nearly 80 years we have been using insects as indicators of when and where death occurred to assist us in criminal proceedings in court, and we have long known about their effectiveness at turning up at the scenes of dastardly deeds.

 

In fact the ability to locate dead bodies is marvellous, and of primary importance are the flies from the family Calliphoridae, the blow flies. These include the common flies - the green bottles and the blue bottles - and many are very large and metallic-looking ... and arguably very attractive! These flies are always the first on the scene and they have an amazing ability to smell - they can detect a fresh corpse from up to 16 km away!

 

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How can you not but admire this beautiful little creature? A Chrysomya megacephala male

 

Now, we know that these types of flies only lay their eggs on dead material so the maggots only develop after death (maggots living on live flesh is a whole different but interesting subject ... and really not for the faint-hearted). So, if we find maggots that are five days old, we can confidently say that the minimum postmortem interval (PMI) is five days - i.e. death could not have happened less than five days previously (it could be more, but it can't be less). However, under different conditions and differing temperatures, the development rate of the maggots varies and this is why we are still studying these species. And we know this because researchers have been working on the development rate of these flies for years and years.

 

Martin and Amoret have at times had decomposing material in the tower at the Museum (this has sometimes resulted, in the dead of winter, an enormous blue bottle winging its way down the stairs to come and say hello to the rest of us whilst we have our lunch; very friendly I thought). Up in the tower they are creating different ambient conditions to enable them to work out how this affects the developmental rate of the maggots and therefore more accurately determine time of death.

 

This idea is being used on a much grander scale in America where, in Tennessee amongst other places, there are facilities where people have donated their own bodies(!) after death to enable in-depth research into the decomposition processes. The Forensic Anthropology Centre, more colloquially known as the body farm is one such place.

 

The facility is located in an area of secluded woodland where there are many different experiments performed to look at the impact of different environmental factors on decomposition. Amoret herself conducted some experiments here to determine how comparable pig and human decomposition was (it is!) and I recently attended an entomology conference in Knoxville and listened to lectures from many forensic entomologists that either work there or utilise the knowledge that it generates.

 

So the fly that everyone goes 'ugh!' at is in fact an incredibly useful agent of the law in addition to its being a rubbish disposal unit and a 'keep the community tidy' advocate! Brilliant things - I have long been fascinated with maggots and their fantastic adaptability to penetrate so many different feeding niches!

 

Listen to Who's the Pest online at the BBC website

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Recently, I have been quiet in the land of blogs but fear not - this was not due to the lack of things fly-related but rather the opposite. I have been working on a three-part BBC Radio 4 series on all things funky about insects and what we can learn from them - not just on a taxonomic or ecological scale but also thinking about their adaptions and functionality, and how we can utilise this.

 

Over the last month or so, I have possibly had the most fun an entomologist can have without a net and a few million dead flies. I was approached a while back by Laura Thomas, a BBC radio producer, about presenting a three-part series on insects that would involve me interviewing some of the most innovative individuals whose work focuses on many different aspects of insect ‘technology’ (I use that term loosely) ...

 

And so I have dangled from a ceiling, played with spiders, eaten bees, admired bot flies, and seen entomo-bots, to name just a few things. And it’s been amazing. I have probably said “that’s marvellous” more than any other phrase, and have wound up all those around me with astonishing facts - I am a pub quiz waiting to happen; my brain is full of wonder and awe. Anyone who does not love insects does not love life!

 

OK, so to my first story from the series … sniffer bees. I was possibly most excited about this out of all of my encounters (however, next week I will say the same about the story I'll cover then, and then the same the week after). These amazing creatures are actually your bog-standard honey bees - making honey and saving us as part of their daily routine!

 

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An amazing honey bee, Apis mellifera

 

And I am not alone in thinking that they are amazing - sniffer bees have caught a lot of other people's imagination:

 

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So, my producer and I headed out of London one cold day to visit Inscentinel, based in Harpenden, Herts. In one innocuous-looking building, up a flight of stairs and round the corner in a small lab, all the action happens. There are two fume hoods, both being used by people wafting chemicals to bees in pods. And to talk me through everything was Dr Maxim Rooth.  Now his biog tells us that he is not an entomologist - far from it:

 

 

‘Dr Maxim Rooth has a BSc in biological and medicinal chemistry and an MSc in biological chemistry. He went on to specialise in optical biosensors … and completed his PhD in chemistry at Exeter University. He has a thorough knowledge of biosensors, surface chemistry, colloid chemistry and bio-conjugation.’

 

 

So what is it about his background that makes him so useful? It is his knowledge of biosensors that is the key. Maxim's group use the bees' natural responses to certain stimuli and, by using optical biosensors, they have developed a machine that is capable of detecting chemicals to help us in locating - among other things - bombs and drugs! Way to go bees.

 

For years we have been using bees in warfare: hurling nests of angry bees about. We have chucked them across the water at opposing ships and launched them on specially developed trebuchets. But recently we have started to think about how to use them to assist us in ways other than warfare, such as detection of drugs, and even more cunningly in detecting illnesses within humans.

 

Previous studies have used bees and their famous waggle dance to determine the position of land mines ... have I said it yet, what marvellous little creatures. For example, the BBC have already covered a story of work conducted by Professor Nikola Kezic, about the use of this technology to find land mines in Croatia. Sandia, University of Montana is another making use of bees in this way. This research is happening all over the planet - and quite rightly so as land mines are still a huge problem (the Red Cross states that there are 45 to a 100 million land mines still active).

 

So how does this work? You make a concoction of a sugar solution containing the chemical (in this case TNT - or one of the smelly components of it; I am very technical!). You then feed this to the bee! Different studies use different methods to do this. This is an image from the Sandia group where they have made up pots of the solution. The bees in this instance feed on the sugary solution and then head off into the wilderness:

 

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Feeding bees chemical-laced sugar solution

 

You can either spot the bees that have detected land mines with some binoculars(!) or you can develop highly sophisticated sensory devices to do the same ... I think you can probably guess which technique is the favoured one. Inscentinel have used this idea of chemical detection and taken it a step further ... bees have tongues, and long ones at that:

 

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Bees have a long tongue relative to their body size

 

What happens when you feed them a solution with the chemical of choice is that, when they then come across the chemical again, they stick their tongues out! “Marvellous”, I hear you cry (I almost did when they let me feed one to see this in action). And they respond this way because they associate the chemical with the sugar solution upon which they have been fed.

 

Now, in the past, we have used sniffer dogs and they are very effective, but dogs are expensive and take a long time to train ... and then retrain, because they eventually forget. Bees on the other hand take about 5 seconds to train (to be sure though, they repeat the training six times and then they give them a dummy test). In a Naked Scientist article on sniffer bees, research scientist Dr Nesbit says:

 

“Bees are at least as good as sniffer dogs but are cheaper and faster to train, and available in much larger numbers ... Bees can detect some odours that are present in parts per trillion - that’s equivalent to detecting a grain of salt in an Olympic-sized swimming pool.”

 

Just as Pavlov's dogs salivated at the sound of a bell due to their associating it with food, when the bees next smell the target chemical they automatically stick out their tongue as they believe that food will appear. And, unlike sniffer dogs, bees cannot help but do this time and time again as it is an innate response - dogs often get bored and forget they are being employed on top military assignments!

 

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For the sniffer machine, each bee is placed in a little pod (they are put in a fridge first to make them dozy!). Then they place the suspect solution on their antenna, where chemoreceptors cause a Pavlovian response if it contains the target chemical.

 

pavlov.jpgOne of Pavlov’s actual dogs is now a museum specimen! Though, sadly, not one of ours.

 

And how does this relate to Maxim and his knowledge of biosensors? Well when the bees stick their tongues out, it passes through an infrared beam thus disrupting it. When all the bees are doing this (there are 36 in the machine) at once we can be pretty confident that the chemical is present.

 

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Bees lined up in their pods and ready for action!

 

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The hand held sniffing machine!

 

Such a simple and inexpensive idea, showing us once more that nature is very clever! P.S. I want one of these machines...

 

Listen to Episode 1 of Who's the pest?

Erica McAlister

Erica McAlister

Member since: Sep 3, 2009

I'm Erica McAlister, Curator of Diptera in the Entomology Department. My role involves working in the collection (I have about 30000 species to look after and over a million specimens), sometimes in the lab, and thankfully sometimes in the field.

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