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.

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.

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?”!

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.

 

 

The future of UK entomology is in safe hands – Royal Entomological Society Postgraduate Forum 2016

A couple of weeks ago (11-12 February), I had the privilege and honour to attend the latest in the excellent series of Royal Entomological Society Postgraduate Forums, this year held at Harper Adams University (HAU) and organised by Claire Blowers and Jordan Ryder, both of whom are PhD students at HAU. Although the Royal Entomological Society (RES) is sometimes still thought of as being a somewhat stuffy and traditional learned society, compared with, for example, the British Ecological Society, which had student membership rates long before the RES, it has in some student-related areas, led the way, the Postgraduate Forums being a great example. The RES ran the first PG Forum in, as far as I can tell, 2000, although their reports are only published from 2007 onwards. The PG Forums are run by postgraduate students and the idea is to give PhD and MSc students the opportunity to present their work to their own community. A few more established entomologists are usually invited as keynote speakers to address topics that are of particular interest to the organising committee, and hopefully, give delegates useful advice and/or examples of how an entomological career might develop. If I remember correctly I was one of the first ‘more established entomologists’ guest speakers.   I think I spoke about how to get published without being too traumatised by the experience. I was asked back a few years later (2008) and spoke about the future of entomology as a discipline, with a somewhat pessimistic title, despite which my conclusion was

decidedly upbeat, although my optimism about NERC was not borne out as they managed to fund the

the wrong sort of taxonomy.

This time I was asked to talk about applied entomology, so decided to base the talk on my own career as I felt this would give the audience a flavour of what they might expect and also of course the opportunity to laugh at the long-haired 1970s version of me and to

recall my introduction to the concept of Integrated Pest Management (and of course aphids).

I also highlighted the huge changes that have happened in the technology surrounding paper writing since I wrote my first paper in 1979.

Our figures were drawn using graph paper, tracing paper, Rotring pens, Indian ink and, if you did not have LetraSet© using a stencil.

My overall message was that you shouldn’t feel constrained by the subject of your PhD, many opportunities are open to you and being a university academic is not the only way to have an enjoyable career in entomology, as Richard Greatrex (Syngenta Bioline), Simon Carpenter (Pirbright) and Sarah Beynon (Dr Beynon’s BugFarm) pointed out, and most importantly, never forget team work and collaboration make life so much easier and productive.

Always give credit where it is due.

Sarah Beynon gave a hugely entertaining talk, I was so pleased that I had gone before her, as otherwise I would have felt very inadequate 🙂

Amoret Whitaker spoke about her career in forensic entomology

and the conference concluded with a brief presentation by Luke Tilley the Outreach Officer for the Royal Entomological Society.

Most importantly of course were the next generation of entomologists, who gave excellent talks and produced some great posters. Unfortunately I had other appointments on the second day so missed some of the talks but I was able to see the winning talk by Dave Stanford-Beale about his experiences in Honduras collecting Saturnid moths for his MSc project.  Incidentally, Dave successfully completed the MSc in Entomology at Harper Adams University in September 2015.

There were some excellent posters, all were very good, and it was great to see some of my former MSc students again.

The social side of things is always important and we enjoyed a superb conference dinner with an accompanying entomological quiz; won by the younger generation rather than us ‘old timers’ :-), which also gave the contestants the chance to use their imagination in devising team names.

The winning team and their entomological prizes

On the evidence of the two days, the excellence of the oral presentations and the subject matter and high standard of presentation of the posters, I am confident that the future of UK entomology is in good hands. Well done all of you and especially to Jordan and Claire for volunteering to take on the responsibility for organising the event.  I also think that we should tank Scott Dwyer, currently on the MSc Entomology course, but heading off to Warwick University to do a PhD in October, who has volunteered to host next year’s event.

 

Post script

And many thanks to all those delegates who posted pictures on Twitter, which allowed me to record this event with more, and better photographs, than I managed to take.