Tag Archives: mosquitoes

Pick and Mix 28 – some video treats

A very interesting, if somewhat gruesome video, of a botfly larva being removed from a human

Continuing with the fly stuff, here are some maggots having an evening meal 🙂 Seriously though, the article is all about using insects as food

And continuing with flies and food – don’t forget that bees are not the only pollinators

Now some hungry mosquitoes, which are of course. also flies

More flies – this time on how to stop them eating your wheat crop

Cockroach farming for food and medicine

Beetles like light too

Magnificent Monarchs in flight – a moving experience

A musical introduction to insect orders

A moving video from a teenage girl about insect extinction

3 Comments

Filed under Pick and mix

What use are bedbugs?

As an entomologist, I have, over the years, become used to being asked by non-entomologists “What use are wasps?” My wife and mother-in-law being frequent interrogators. What they actually mean is “What use are Vespids?”, in particular what the Americans call yellow jackets, and their ilk.

Wasp

Not a bed bug – The European wasp Vespula germanica https://en.wikipedia.org/wiki/Yellow_jacket#/media/File:European_wasp_white_bg.jpg

I now have a well-polished response where I explain that wasps are beneficial insects keeping the caterpillars that eat their garden plants under control and that the occasional hole they make in my interlocutor’s soft fruit is just payment for the job they are doing. I am not saying that this answer always satisfies them, especially if their plums have been devastated, but at least they agree that there is some justification for their existence.

Unfortunately I now have a new question to answer. Last summer (2015) my wife and I took our usual holiday to France. We put our car on the Brittany Ferry, m/V Mont St Michel, and after a drink in the bar retired to our cabin, 9108 in case you want to avoid it, me in Bunk A my wife in Bunk B.

Bedbug2

Sailing in comfort?

The next morning my wife was not a happy lady and the question I now have to answer is “What use are bedbugs?”!

Bedbug3

The bed bug culprit, Cimex lectularius and victim

I have in the past made a convincing case (well I think so) for the usefulness of mosquitoes compared with pandas, but I suspected that making a case for the usefulness of bed bugs that would satisfy my wife, might be more difficult.

Even the Encyclopaedia of Life has nothing good to say about bed bugs. For evolutionary biologists, ecologists and entomologists, bed bugs are very useful in allowing us to relate horror stories about non-conventional sex. Male bed bugs favour a very robust approach to reproduction, as they indulge in what is somewhat coyly termed ‘traumatic insemination (Reinhardt & Siva-Jothy, 2007). Basically they don’t bother with the female genital opening, they mount the female and search for a pouch (Organ of Ribaga or ectospermalage) on the underside of the female (they have been known to mount other males) which they pierce with their intromittent organ (penis) and into which they release their sperm. The spermatozoa then migrate through the body of the female to the oviduct, taking from 2-10 hours to do so (Cragg, 1920). Apparently males never use the genital tract for insemination (Reinhardt & Siva-Jothy, (2007). This somewhat unconventional approach to mating has, as you might expect, harmful effects on the female, with life spans being reduced by about 30% or even causing death (Morrow & Anrnqvist, 2003), multiple matings can be particularly damaging (Mellanby, 1939).

For their human hosts, bed bugs can have a number of unpleasant effects (Reinhardt & Siva-Jothy, 2007), ranging from psychological distress, allergic reactions as in the case of my wife, secondary infections and economic costs, especially if you are an hotelier. All in all, not a very promising candidate for being useful to us humans 🙂 I was beginning to feel that bed bugs had no redeeming features and that if there was a coordinated campaign calling for the destruction of the entire species, I would be unable to defend them. Then a former student came to their rescue. In desperation, I had emailed Mike Siva-Jothy at Sheffield University who has worked on bed bugs since the late 1990s. He passed my email on to Sophie Evison (a former MSc student of mine) and she came to their rescue as follows

I’ve had a think about this, and I think there are two approaches: 1. dazzle them with the traumatic insemination story or 2. Forensics. I’ve not looked into it, but I’m pretty sure a situation could arise where the contents of a bedbug could drop someone in it, or even perhaps prove an alibi! Do you think your wife would accept that as reasonable?”

I was pretty certain that my wife would not be happy with option 1, but felt that option 2 was definitely worth following up. I very quickly found a paper (Szalanski et al, 2006) in which the possibility of testing the DNA of the blood found in bed bugs was suggested as having a possible forensic application. According to Wikipedia (well if it is good enough for my students) there has already been some success in real life using this very approach. I was now pretty confident that I had found an answer to the question posed by my wife. To be fair, I tested both of them out on her. As predicted, she did not buy the evolutionary biology aspect of the traumatic insemination story as being of any use, but as a great fan of the CSI and NCIS TV shows, she has grudgingly accepted that there is indeed a use for bed bugs! I just hope that all the bed bugs out there appreciate all the effort I have gone to on their behalf 🙂 If anyone else has further suggestions please let me know.

References

Cragg, F.W. (1920) Further observations on the reproductive system of Cimex, with special reference to the behaviour of the spermatozoa. Indian Journal of Medical Research, 8, 32-79

Mellanby, K. (1939) Fertilization and egg production in the bed-bug Cimex lectularius L. Parasitology, 31, 193-199

Morrow, E.H. & Arnqvist, G. (2003) Costly traumatic insemination and female counter-adaptation in bed bugs. Proceedings of the Royal Society of London Series B, 270, 2377-2381

Reinhardt, K. & Siva-Jothy, M. (2007) Biology of the bed bugs (Cimicidae). Annual Review of Entomology, 52, 351-374

Szalanski, A.L., J.W. Austin, J.A. McKern, C.D. Steelman, D.M. Miller, and R.E. Gold. 2006. Isolation and characterization of human DNA from bed bug, Cimex lectularius L., (Hemiptera: Cimicidae) blood meals. Journal of Agricultural and Urban Entomology, 23, 189-194.

 

 

7 Comments

Filed under Bugbears, EntoNotes, Uncategorized

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.

6 Comments

Filed under Bugbears