Monthly Archives: October 2014

A world without Pandas – would it make a difference? OR Conservation versus eradication – do some species deserve to die?

Before you all get excited and ready to shoot me down in flames, this post is not about pandas 😉 It is about how we, as humans, have a very warped view about the value of the species with whom we share this planet – note I did not say OUR planet.

Imagine this as a newspaper headline; Scientists discover a way to eradicate Siberian tigers or this; Destroy Polar Bear menace say local residents or this, Malawi’s ”Serial Killer” Crocodiles Cause Havoc among the Blind, actually this last one is true http://www.digitaljournal.com/article/33608 😉

Most people on seeing headlines like those would be putting pen to paper, typing tweets, sharing links and generally making a huge fuss. Replace tigers, pandas and crocodiles with mosquitoes, aphids and spiders and the only people making a fuss would be that other endangered species,  entomologists,  as evidenced by this Twitter conversation sparked off by this article http://www.radiolab.org/story/kill-em-all/

Entodebate

I know I said this wasn’t about pandas but bear with me for a minute.

The following sentences are from the WWF site http://wwf.panda.org/what_we_do/endangered_species/giant_panda/panda/why_we_save_the_giant_panda/

“The giant panda is one of these species threatened to be wiped off the planet. Ironically, it is also one better known and loved species in the world and one of the strongest symbols of nature conservation. That is one of the main reasons why they are so important: by mobilizing people to save the panda, we are actually helping preserve the rich biodiversity, plants, landscapes, other animals that need to be there in order for the pandas to survive.

The region where pandas live, in the Yangtze Basin and its magnificent forests are home to a stunning array of wildlife such as dwarf blue sheep and beautiful multi-coloured pheasants; as well as a number of other endangered species, including the golden monkey, takin and crested ibis. The panda’s habitat is also home for millions of people. This is the geographic and economic heart of China. By making this area more sustainable, we are also helping to increase the quality of life of local populations”
By rewriting this very slightly and using Anopheles gambiae and mosquito instead of panda, you get this somewhat thought-provoking version;

Anopheles gambiae is one of those species threatened to be wiped off the planet by the deliberate action of man (http://synbiobeta.com/oxitec-arming-insects-eliminate/ and http://www3.imperial.ac.uk/newsandeventspggrp/imperialcollege/newssummary/news_10-6-2014-16-5-11).

The region where Anopheles gambiae live, sub-Saharan Africa, and its magnificent forests and savannahs are home to a stunning array of wildlife such as lions, elephants and giraffes; as well as a number of other endangered species, including the cheetah and black rhino.

That is one of the main reasons why they are so important: by mobilizing people to save the mosquito, we are actually helping preserve the rich biodiversity, plants, landscapes, other animals that need to be there in order for the mosquitoes to survive.

The mosquitoes’ habitat is also home for millions of people. This is the geographic and economic heart of Africa. By making this area more sustainable, we are also helping to increase the quality of life of local populations”

 

I know that this is a somewhat extreme example, and I am in NO way whatsoever saying that malaria prevention is a bad thing and that we should allow millions of people to die every year. What I am proposing is that we should look at the ways we can protect people from malaria and other fatal and debilitating diseases and our crops from the depredations of pests and diseases that don’t involve the eradication of other species on the planet.
Conservation biology teaches us that we should preserve species for a number of reasons.  Common textbook examples usually include the following:

Resource values – all species may have an economic or ecological value, some of which we do not yet appreciate e.g. Food, pharmaceuticals, watershed regulation, coastline stabilisation, reefs for fisheries, tourism, education, ecological baselines, habitat reconstruction etc.

Non-resource values – all species should be valued anyway e.g. Religion, moral codes, social/cultural values, existence values, intrinsic value, and aesthetic values

Precautionary principle – all species should be preserved just in case – the rivets and spaceship (aeroplane) theory

This latter theory comes from the preface to Paul Ehrlich’s 1981 book, Extinction, where he imagines a passenger inspecting the ‘plane he is about to fly in. The passenger notices someone popping rivets out of the wings and asks what he is doing. The rivet popper replies that the passenger shouldn’t worry because not all the rivets are necessary. The rivets represent species and the rivet popper represents humanity, and the ‘plane the planet Earth. Ehrlich predicted that continuing to pop the rivets of ecosystems would lead to “a crumbling of post-industrial society” and demanded that the rivet popping be stopped.

Michael Soulé, a pioneer conservation biologist and former PhD student of Paul Ehrlich wrote

untimely extinction of populations and species is bad, conservation biology does not abhor extinction per se. Natural extinction is thought to be either value free or good because it is part of the process of replacing less well-adapted gene pools with better adapted ones. Ultimately, natural extinction, unless it is catastrophic, does not reduce biological diversity, because it is offset by speciation”

Conservation principles have moved from the preservation of single species to an ecosystem point of view as outlines recently by Professor Georgina Mace of University College London,

Mace picture

although the concept of keystone species, a term first coined by Richard Paine in 1969 has, particularly if the keystone species is vertebrate, had a marked influence on where conservation efforts have been directed over the years.

The concept of ecosystem services where species can be assigned an economic value depending on the services they offer to humankind  is not new (e.g. Hooper, 1970; Westman, 1977), but has increasingly and unfortunately allowed politicians and research funders to make decisions about the worth of species from a purely human viewpoint. As a result, when discussing the eradication or otherwise of species there is a definite bias towards the ‘charismatic mega-fauna’ whether they are keystone species or not, and those species that cause us discomfort must argue very hard for their preservation; see for example this extract from Jennifer Fang’s (2010) article.
A stronger argument for keeping mosquitoes might be found if they provide ‘ecosystem services’ — the benefits that humans derive from nature. Evolutionary ecologist Dina Fonseca at Rutgers University in New Brunswick, New Jersey, points as a comparison to the biting midges of the family Ceratopogonidae, sometimes known as no-see-ums. “People being bitten by no-see-ums or being infected through them with viruses, protozoa and filarial worms would love to eradicate them,” she says. But because some ceratopogonids are pollinators of tropical crops such as cacao, “that would result in a world without chocolate”.

“They don’t occupy an unassailable niche in the environment,” says entomologist Joe Conlon, of the American Mosquito Control Association in Jacksonville, Florida. “If we eradicated them tomorrow, the ecosystems where they are active will hiccup and then get on with life. Something better or worse would take over.” 

 

On the plus side sometimes the ecosystem services concept can be used to highlight the benefits of the smaller and often over-looked species, but yet again only if a substantial economic value can be assigned to them http://www.theguardian.com/environment/2014/oct/05/threatened-species-cannot-afford-to-lose-age-of-extinction

 

Personally, I am a great believer in retaining as many species as we can, so the deliberate eradication of species from their natural environments because we find them a nuisance makes me uneasy. We share this world, we don’t own it, so finding a way to live with ‘nuisance’ species must be a better option than eradicating them.

As a parting thought, consider these words from Ehrlich & Mooney (1980), and also bear in mind the UK Government’s recent Biodiversity Offsetting policy.

“Although there are numerous examples of unsuccessful substitutions, successful ones are hard to identify.

At some point the costs of substitution will almost certainly become unbearable. Therefore, it seems that a conservative approach, emphasizing the careful preservation of ecosystems and thus the populations and species that function within them is absolutely essential.”

Tea pot

 

Some things once broken are very difficult to put back together and might not work in the same way that they did before they were broken

http://100percenttea.blogspot.co.uk/2007/11/how-not-to-repair-broken-teapot.htmle

 

References

Ehrlich, P. R. & Mooney, H.A. (1983) Extinction, substitution, and ecosystem services. BioScience, 33, 248-254

Fang, J. (2010) A World without mosquitoes. Nature, 466, 432-434

http://www.nature.com/news/2010/100721/full/466432a.html

Hooper, J.F. (1970) Economics, the ecosystem and conservation. Journal of Range Management, 23, 148-150

Mace, G. (2014). Whose conservation? Science, 345, 1558-1560.

Paine, R. T. (1969). A note on trophic complexity and community stability. American Naturalist,  103, 91-93.

Soulé, M. E. (1985). What is conservation biology? Bioscience 35, 727-734.

Westman, W.E. (1977) How much are nature’s services worth? Science, 197, 960-964

 

Post script

1Somewhat ironically Paine’s 1969 paper in which he coined the term keystone species dealt with two invertebrate species,  starfish.

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First steps towards an entomological career – A nostalgic reminiscence

Our new Freshers have now found their feet and most now no longer have to ask directions to buildings and lecture theatres. It came as a bit of a shock to me to suddenly realise that this time forty years ago I was in a similar position at Leeds University, although probably feeling somewhat more lost than our first year students because even then, Leeds was a big university (10 000 students; small compared with most universities now, but the biggest outside London then).   Then & Now Two weeks into term and I was experiencing my first ever entomology lectures – my degree was in a now extinct subject, Agricultural Zoology, which was essentially entomology and parasitology, with a strong agricultural slant. I still have the books that I bought in those first stumbling days (as Agrics we drank rather a lot) towards my career as a professional entomologist. Textbooks I note that I did not buy the two Entomological bibles of our day, Imms (A General Textbook of Entomology) and Wigglesworth (The Principles of Insect Physiology) until the following year; actually during the summer vacation so I must have been very keen and feeling quite rich  😉 I drank and read my way through undergraduate life managing to fit in an entomological expedition to Trinidad in 1975 where I reacquainted myself with the Caribbean insects that had first sparked my interest in entomology as a child in Jamaica. Drink & Trinidad I also discovered that, to quote the advertising posters all over the island,  “in Trinidad a beer is a Carib”!

A beer is a carib

Despite the beer, the sunshine and the exotic flora and fauna, 1975 was the year that I decided aphids were the most fascinating of all insects and what I wanted to work on when I graduated.  I also realised that you didn’t need to travel to exotic places to do interesting fieldwork and make new discoveries. Graduation & FieldworkEven with all the distractions of student life, I did graduate and went on to do a PhD working on cereal aphid ecology. PhD work

PhD work – A good job Health & Safety hadn’t been invented 😉

I had some great entomological lecturers as an undergraduate, all of whom helped me get to where I am today;  Brian Whittington, Noel Gibson, Edward Broadhead, Steve Sutton and the somewhat eccentric Dick Loxton who took us on our field course and introduced us to extreme sweep netting, something I still do to do this day! Extreme sweep netting References

Barnes, R.D. (1974) Invertebrate Zoology, 3rd Edition, W B Saunders & Co. Philadelphia

Barrington, E.J.W. (1967) Invertebrate Structure & Function, Nelson, London

Cox, F.E.G., Morton, J.E., Phillips Dale, R., Nichols, D., Green, J. & Wakelin, D. (1969) Practical Invertebrate Zoology, Sidgwick & Jackson, London

Grove, A.J. & Newell, G.E. (1969) Animal Biology, 8th Edition, University Tutorial Press Ltd. London Imms, A.D. (1947) Insect Natural History, Collins, London

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Entomological classics – The Malaise Trap

More years ago than I care to remember, my friends and I were playing the now, very non-PC game of Cowboys and Indians, when we saw through the trees, what we thought was a tent. On sneaking up to it we found that, if it was a tent, it wasn’t very watertight!  There were no sides, instead there was a central panel and the whole thing was made of netting.  What we had actually found, was of course a Malaise trap, although of course we did not know this at the time.  It was only later as an undergraduate that I realised what we had found all those years before.

So exactly what is a Malaise trap and how did it come into being? The Malaise Trap is a relatively new invention.  It was invented by the Swedish entomologist, Dr René Malaise in the 1930s (hence the name) and revealed to a more general entomological audience in 1937 (Malaise, 1937).  It was actually designed as a replacement for the traditional hand-held collecting net, which as Malaise states in the introduction to his paper ‘”Since the time of Linneaus, the technique of catching insects has not improved very much, and we are to-day using the same kind of net as then for our main instrument”.

I was amused, when reading on further, to find that my childhood gaffe of confusing a Malaise Trap with a net was fully justified. Malaise, later in the same paper writes, ”During my extensive travels I have repeatedly found that insects happened to enter my tent, and that they always accumulated at the ceiling-corners in vain efforts to escape at that place without paying any attention to the open tent door”. He then goes on to describe how he conjectured that “a trap made as invisible as possible and put up at a place where insect are wont to patrol back and forth, might catch them much better than any tent, and perhaps better than a man with a net, as a trap could catch them all the time, by night as by day, and never be forced to quit catching when it was best because dinner-time was at hand”.

He thus set about constructing a trap based on the idea of an open tent with a collecting device attached to the central end pole to take advantage of the fact that most insects when encountering an obstacle tend to fly upwards. On reaching the apex of the tent, the only way out is into the collecting device which is filled with a killing agent.  It is in effect, a flight intercept trap, but unlike window traps (subject of a later post), the insects instead of falling into a collecting device, head upwards and collect themselves. Malaise tested his first version of the trap on an expedition to Burma and found them to be a great success “every day’s catch from the traps grew larger and larger, and sorting it required more and more time”. He found the traps particularly good for Diptera and Hymenoptera but also very good for Coleoptera and Noctuid and Sphingid moths.  He also mentions catching Hemiptera.

In outward form, the Malaise Trap has remained fairly unchanged since its invention. The first versions were apparently fairly heavy, having a brass insect collecting cylinder and also only had one opening.  Malaise recognised the disadvantages of the single entrance version and suggested in the 1937 paper that a bilateral model would be more effective.  These followed in due course. Modified versions using plastic cylinders and different netting material were  invented in the 1960s (Gressit & Gressit, 1962; Townes, 1962; Butler, 1965).  Townes’s paper gives a very detailed description of the construction and use of modified Malaise traps (90 pages) in contrast to Butler’s three page description of a cheap and cheerful version made from a modified bed-net.

Nowadays, entomologists world-wide, particularly Dipterists and Hymenopterists, use Malaise traps of various designs and colours, and cost.  In the UK they are available from commercial outlets at prices ranging from £60 to £165. They are extremely effective and we use them to collect insects for our practical classes in the Entomology MSc based at Harper Adams University.

    Malaise traps

Malaise trap in operation, Harper Adams University, Shropshire, UK.

 

References

Butler, G.D. 91965) A modified Malaise insect trap. The Pan-Pacific Entomologist, 41, 51-53

Gressitt, J.L. & Gressitt, M.K. (1962) An improved Malaise Trap. Pacific Insects, 4, 87-90

Malaise, R. (1937) A new insect-trap.  Entomologisk Tidskrift, Stockholm, 58, 148-160

Townes, H. (1962) Design for a Malaise trap. Proceedings of the Entomological Society of  Washington, 64, 162-253

 

Post script

Malaise was not just an entomologist; he was an explorer and a passionate believer in the existence of Atlantis. A detailed biography of this extraordinary character can be found here, including a photograph of the original Malaise trap.

 

Post post script

I was amused to find in the 1949 edition of Instructions for Collectors No. 4a, Insects (Smart, 1949), this somewhat dismissive comment about the Malaise Trap “It is a very novel idea and captures large numbers of insects, but as at present designed is rather cumbersome, and since its design will probably be modified with experience it is not described here

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