Tag Archives: insects

Should entomologists change their name to insectologists?

In case you are wondering, this is not a totally tongue in cheek post. Over the years it has become very clear to me, that many people, even those with degrees, have no idea what an entomologist is. On being told that I am an entomologist, most people look blankly at me, and pass on rapidly to another topic. Despite the importance of the subject, the term entomology is not very widely known.  Sadly, to those of us who study insects, this is no longer hugely surprising.  More surprising though, is how few of those people then ask me what an entomologist is. I haven’t asked any ornithologists, botanists, zoologists, my paediatrics daughter, or my consultant gynaecologist brother if they suffer similar responses on being asked their occupations, but I suspect that they suffer from far fewer blank looks than I do.

So, what can we do about this lamentable state of affairs?  I, and other entomologists have long lamented the lack of knowledge and interest in these, the most important, and to me, most fascinating members of the animal world, shown by the majority of humans. What is it about entomology that makes it such a niche subject?

All is not lost. When I do get the chance to enlighten those that ask, and tell them that entomologists study insects, I am relieved to find that they do know what they (insects) are, even if they do respond, with “oh bugs, that’s what I thought”, which is at least preferable to “creepy crawlies” which is another common response. So are we too elitist, too proud of our discipline to give it a more accessible name? Ornithologists don’t, as far as I know, call themselves birdologists, and herpetologists don’t need to go around describing themselves as frogologists, snakeologists or whateverologists?  They don’t have to, they live in a world surrounded by the constant stream of vertebrate propaganda coming from the biased charismatic mega-fauna, backbone dominated world we live in. (I’m not bitter, honest).

Going back to my question about elitism in our discipline.  Our societies worldwide are known as entomological societies, some such as the one I have been a proud Fellow since 1977, are even preceded by the word Royal, and the Royal Entomological Society of London is not alone, there is also the Royal Belgian Entomological Society :-). What about the journals that entomological societies produce and those in which entomologists publish?  As you might expect the majority of the titles contain the word entomology but not exclusively.  The two biggest entomological societies, The Royal Entomological Society (RES) and the Entomological Society of America (ESA), produce six and eight journals respectively in addition to their newsletters and handbooks.  Of the six RES journals, two use insect instead of entomology, Insect Conservation & Diversity and Insect Molecular Biology. Similarly the ESA have two insect named journals, Journal of Insect Science, Insect Systematics and Diversity, and also two that eschew mention of both entomology and insects, Journal of Integrated Pest Management, and Arthropod Management Tests. The International Union for the Study of Social Insects, not technically a society, produces the well-known and highly respected journal, Insectes Sociaux.

Outside the world of learned entomological societies there are a handful of entomological journals that use insect instead of entomology, namely, Journal of Insect Conservation, Journal of Insect Physiology, Insects and Insect Science, three of which I have published in (Cameron & Leather, 2012; Oliver et al., 2012, Cooper et al., 2014). There is also of course, The Bulletin of Insectology, in which I have also published (Benelli et al, 2015).

Entomology is obviously not a sacred term, and in the interests of getting more people interested in the wonderful world of insects and letting them know what it is we do, we should perhaps, be less precious about being entomologists, and become insectologists when appropriate.  That said, I don’t think I will ever be able to bring myself to say that I am a bugologist or creepycrawlyologist, but I I could certainly live with being an insectologist now and then.

 

References

Benelli, M., Leather, S.R., Francati, S., Marchetti, E. & Dindo, M.L. (2015) Effect of two temperatures on biological traits and susceptibility to a pyrethroid insecticide in an exotic and native coccinellid species. Bulletin of Insectology, 69, 23-29.

Cameron, K.H. & Leather, S.R. (2012) Heathland management effects on carabid beetle communities: the relationship between bare ground patch size and carabid  biodiversity. Journal of Insect Conservation, 16, 523-535.

Cooper, L.C., Desjonqueres, C. & Leather, S.R. (2014) Cannibalism in the pea aphid, Acyrthosiphon pisum. Insect Science, 21, 750-758.

Oliver, T.H., Leather, S.R. & Cook, J.M. (2012) Ant larval demand reduces aphid colony growth rates in an ant-aphid interaction. Insects, 3, 120-130.

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Ten more papers that shook my world – complex plant architecture provides more niches for insects – Lawton & Schroeder (1977)

Some years ago I wrote about how one of my ecological heroes, Sir Richard Southwood (later Lord Southwood), influenced my research and stimulated what has become a lifelong interest of mine, island biogeography, in particular the iconic species-area relationship. Apropos of this it seems apposite to write about another huge influence on my research, Sir John Lawton.  I first encountered John*, as he was then, at the tender age of 17, when our Sixth Form Science class were bussed from Ripon Grammar School to York University to hear a very enthusiastic arm-waving young ecologist, yes John Lawton, talking about food webs. Excellent as it was, it wasn’t, however, this talk that inspired me :-), but a paper that he and Dieter Schroeder wrote a few years later (Lawton & Schroeder, 1977), in which they showed that structurally more diverse plants potentially hosted more insect species per unit range than those plants with less complex architecture.  A couple of years later Strong & Levin (1979) showed that this also applied to fungal parasites in the USA.  The mechanism behind the finding was hypothesised to be based on apparency – the bigger you are the easier you are to find, the bigger you are, the more niches you can provide to be colonised, pretty much the same reasoning used to explain geographic island biogeography and species-area accumulation curves (Simberloff & Wilson, 1969). John Lawton, Don Strong and Sir Richard Southwood also highlighted this in their wonderful little book (Strong et al, 1984) which has provided excellent material for my lectures over the years.

As someone who is writing a book, theirs is an excellent example of how you can improve on other people’s offerings.  Staying with the theme of plant architectural complexity, Strong et al (1984) brilliantly reported on Vic Moran’s masterly study on the relationship between Opuntia growth forms and the number of insects associated with them (Moran, 1980).  Vic’s study was an advance on the previous studies because he examined one family of plants, rather than across families, so reducing the variance seen in other studies caused by phylogenetic effects. I should also point out that this paper was also an inspiration to me.

The figure as shown in Victor Moran’s paper.

The revamped Moran as shown in Strong & Lawton (1984).

Okay, so how did this shake my world? As I have mentioned before, my PhD and first two post-docs were on the bird cherry-oat aphid, Rhopalosiphum padi, a host-alternating aphid that uses bird cherry, Prunus padus, as its primary host.  Never being one to stick to one thing, I inevitably got interested in bird cherry in general and as well as eventually writing a paper about it (Leather, 1996) (my only publication in Journal of Ecology), I also, in due course, set up a long term experiment on it, the outcome of which I have written about previously. But, I digress, the first world shaking outcome of reading Lawton & Schroeder, was published in Ecological Entomology (incidentally edited by John Lawton at the time), in which I analysed the relationships between the insects associated with UK Prunus species and their distribution and evolutionary history, and showed that bird cherry had a depauperate insect fauna compared with other Prunus species (Leather, 1985).

I’m not working with very many points, but you get the picture (from Leather, 1985). Bird cherry (and also Gean, the common wild cherry. Prunus avium) hosts fewer insect species than would be expected from its range and history.

This in turn led me on to an even more ambitious project.  Inspired by a comment in Kennedy & Southwood (1984) that a better resolution of the species-plant range relationship would result if the analysis was done on a taxonomically restricted group of plants and by the comment in Southwood (1961) that the Rosaceae were a very special plant family, I spent several months wading through insect host lists to compile a data set of the insects associated with all the British Rosaceae.  Once analysed I submitted the results as two linked papers to the Journal of Animal Ecology.  Having responded to Southwood’s demand that “this manuscript be flensed of its too corpulent flesh” it was eventually published (Leather, 1996).  My somewhat pompous introduction to the paper is shown below.

“This relationship is modified by the structure or complexity of the plant, i.e. trees support more insect species than shrubs, which in turn support more species than herbs (Lawton & Schroder 1977; Strong & Levin 1979; Lawton 1983).”

“Kennedy & Southwood (1984) postulated that if taxonomically restricted groups of insects and/or plants were considered, the importance of many of these variables would increase. Few families of plants cover a sufficiently wide range of different growth forms ranging from small herbs to trees in large enough numbers to give statistically meaningful results. The Rosaceae are a notable exception and Southwood (1961) commented on the extraordinary number of insects associated with Rosaceous trees. It would thus appear that the Rosaceae and their associated insect fauna provide an unparalleled opportunity to test many of the current hypotheses put forward in recent years concerning insect host-plant relationships.”

Cutting the long story short (I am much better at flensing nowadays), I found  that Rosaceous trees had longer species lists than Rosaceous shrubs, which in turn had longer lists than herbaceous Rosaceae.

Rather messy, but does show that the more architecturally complex the plant, the more insect species it can potentially host (from Leather, 1986).

Flushed by the success of my Prunus based paper, I started to collect data on Finnish Macrolepidoptera feeding on Prunus to compare and contrast with my UK data (I can’t actually remember why this seemed a good idea).  Even if I say so myself, the results were intriguing (to me at any rate, the fact that only 19 people have cited it, would seem to suggest that others found it less so), in that host plant utilisation by the same species of Macrolepidoptera was different between island Britain and continental Finland (Leather, 1991).

 

 

From Leather (1991) Classic species-area graph from both countries but some intriguing differences in feeding specialisation.

Despite the less than impressive citation index for the UK-Finland comparison paper (Leather, 1991), I would like to extend the analysis to the whole of Europe, or at least to those countries that have comprehensive published distributions of their Flora.  I offer this as a project to our Entomology MSc students, every year, but so far, no luck ☹

Although only four of my papers can be directly attributed to the Lawton & Schroeder paper, and taking into account that the insect species richness of Rosacea paper, is number 13 in my all-time citation list, I feel justified in counting it as one of the papers that shook my World.

References

Kennedy, C.E.J. & Southwood, T.R.E. (1984) The number of species of insects associated with British trees: a re-analysis. Journal of Animal Ecology, 53, 455-478.

Lawton, J.H. & Schroder, D. (1977) Effects of plant type, size of geographical range and taxonomic isolation on numbers of insect species associated with British plants. Nature, 265, 137-140.

Leather, S.R. (1985) Does the bird cherry have its ‘fair share’ of insect pests ? An appraisal of the species-area relationships of the phytophagous insects associated with British Prunus species. Ecological Entomology, 10, 43-56.

Leather, S.R. (1986) Insect species richness of the British Rosaceae: the importance of host range, plant architecture, age of establishment, taxonomic isolation and species-area relationships. Journal of Animal Ecology, 55, 841-860.

Leather, S.R. (1991) Feeding specialisation and host distribution of British and Finnish Prunus feeding macrolepidoptera. Oikos, 60, 40-48.

Leather, S.R. (1996) Biological flora of the British Isles Prunus padus L. Journal of Ecology, 84, 125-132.

Moran, V.C. (1980) Interactions between phytophagous insects and their Opuntia hosts. Ecological Entomology, 5, 153-164.

Simberloff, D. & Wilson, E.O. (1969) Experimental zoogeography of islands: the colonization of empty islands. Ecology50, 278-296.

Southwood, T.R.E. (1961) The number of species of insect associated with various trees. Journal of Animal Ecology, 30, 1-8.

Strong, D.R. & Levin, D.A. (1979) Species richness of plant parasites and growth form of their hosts. American Naturalist, 114, 1-22.

Strong, D.R., Lawton, J.H. & Southwood, T.R.E. (1984) Insects on Plants – Community Patterns and Mechanisms. Blackwell Scientific Publication, Oxford.

 

 

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Ten more papers that shook my world – When it comes to plant-insect interactions its growth stage, not age that counts Watt (1979)

This is not just about a paper, but also about mentoring!  At the beginning of October 1977, I hesitantly knocked on the door of Professor Tony Dixon’s outer office in the School of Biological Sciences at the University of East Anglia, Norwich.  Tony was to become my PhD supervisor for the next three years and my friend and colleague for the next forty plus years, but until that day I had never met him, as my interview had been conducted entirely by telephone and in those pre-internet days, unless you had met someone at a conference you really only knew them by their papers and reputation.  I knew Tony because of his great little book, The Biology of Aphids which I had bought as an undergraduate in 1975, when I realised that aphids were really cool 😊 I told his secretary who I was and she directed me through to his office.  Tony looked up, said hello and asking me to follow him, took me down to the lab where I was to spend the next three years and introduced me to a tall, moustachioed Scotsman, Allan Watt, whom I was later to discover had a wicked sense of humour, and was to become not just a colleague and collaborator, but also a great friend, a friendship that continues to this day.  Tony’s introduction was roughly along the lines of “This is Allan, he’ll tell you what to do” and he did. Allan was just starting the final year of his PhD which was, like a number of us in Tony’s lab, on cereal aphids, in Allan’s case Sitobion avenae and Metopolphium dirhodum, the two major pests of cereals in the UK at the time.  My PhD was on a less abundant (in cereal crops), but equally problematic aphid, due to its ability to transmit Barley Yellow Dwarf Virus, the bird cherry-oat aphid Rhopalosiphum padi.  Having got my aphid cultures set up and done a couple of practice mini-experiments, I asked Allan what he was doing with his aphids.  He told me that he was looking at the effect of cereal growth stage on the survival and reproduction of his two aphid species and that the age of the plant had a significant effect on the aphids and that this varied between the two species, which he published a couple of years later (Watt, 1979).  Having been immersed in the cereal aphid literature for a couple of months, I knew that no one had done this for my aphid, and even then, being a great believer in “standing on the shoulders of giants” I figured that I could do the same for my aphid, but, in that never ending treadmill of adding novelty, also look at the effect of feeding position*. Allan’s advice and help stood me in good stead, and in due course I successfully published the results of my experiment (Leather & Dixon, 1981).

So, leaving aside me getting a publication as a result of Allan’s paper, how did this shake my World?  Well, first of all, it really drove home to me that plant phenological stage was incredibly important for insect-plant interactions and that unless you know the precise growth stage at which an interaction is happening it is difficult to compare other peoples’ results to yours and each other’s. As a result, it has led me as a reviewer and reader of papers, to be very scathing of phrases such as “ten-day old wheat plant”, “week old cabbage seedlings”, “young pea plant” (Leather, 2010).  It is deeply unhelpful for anyone wanting to repeat or compare similar work.  Just a few degrees difference in temperature over a week can move a plant from one phenological stage to another. There is no excuse for this type of sloppiness.

Two seven-day old wheat plants, same cultivar, same germination date, one reared at 20⁰C the other at 10⁰C. Growth stage 12 versus Growth stage 10 (Growth stages as described by Tottman & Makepeace, 1979).

The same two plants now fourteen day sold, GS 13 versus GS 12

It is not hard to find a solution.  The World has been blessed by the invention of the BBCH** system for coding plant phenological stages (Meier et al., 2009).  This system, which now exists for most major crop plants, including trees, means that there is no excuse for anyone to ever use the phrase “ten-day old plant” or similar wording. If by some chance, your plant does not yet have a BBCH description, either describe the growth stage that your plants are at in very precise terms or take the time to codify it yourself and submit it to a journal such as Annals of Applied Biology which has a long history of publishing such articles.

To be fair, before the BBCH system came into being, people had published descriptions of plant growth stages for some of the major crops, e.g. cereals (Feekes, 1941; Large, 1954), but they were not standardised, and in some cases, too broad-brush.  The stimulus for a standardised, decimal system of coding plant phenological stages was the publication of the Zadoks scale for cereals (Zadoks et al., 1974) and the illustrated follow-up a few years later (Tottman & Makepeace, 1979), the latter being the blueprint on which phenological growth stage papers are now based.

I look forward to the day when authors understand that a precise knowledge of plant growth stage is essential to understanding insect-plant interactions and I do NOT have to chide authors for not using the BBCH codification when I review their papers.

 

References

Feekes, W. (1941) De Tarwe en haar milieu. Vers. XVII Tech. Tarwe Comm. Groningen, 560-561.

Large, E.C. (1954) Growth stages in cereals. Plant Pathology, 3, 128-129.

Leather, S.R. (2010) Precise knowledge of plant growth stages enhances applied and pure research. Annals of Applied Biology, 157, 159-161.

Leather, S.R. & Dixon, A.F.G. (1981) The effect of cereal growth stage and feeding site on the reproductive activity of the bird cherry aphid Rhopalosiphum padi. Annals of Applied  Biology, 97, 135-141.

Meier, U., Bleiholder, H., Buhr, L., Feller, C., Hack, H., Hess, M., Lancashire, P.D., Schnock, U., Strauss, R., Vanden Boom, T., Weber, E. & Zwerger, P. (2009) The BBCH system to coding the phenological growth stages of plants – history and publications. Journal fur Kulturpflanzen, 61, S.41-52.

Tottman, D.R. & Makepeace, R.J. (1979) An explanation of the decimal code for the growth stage of cereals, with illustrations. Annals of Applied Biology, 93, 221-234.

Watt, A.D. (1979) The effect of cereal growth stages on the reproductive activity of Sitobion avenae and Metopolphium dirhodum. Annals of Applied Biology, 91, 147-157.

Watt, A.D. & Dixon, A.F.G. (1981) The effect of cereal growth stages and crowding of aphids on the induction of alatae in Sitobion avenae. Ecological Entomology, 6, 441-447.

Watt, A.D. & Wratten, S.D. (1984) The effects of growth stage in wheat on yield reductions caused by the rose grain aphid, Metopolophium dirhodum. Annals of Applied Biology, 104, 393-397.

Zadoks, J.C., Chang, T.T. & Konzak, C.F. (1974) A decimal code for the growth stages of cereals. Weed Research, 14, 415-421.

 

 

 

*

*Rhopaloisphum padi, in contrast to Sitobion avenae, is usually found on the lower stem and leaves of cereals.

**

The abbreviation BBCH derives from the names of the originally participating stakeholders: “Biologische Bundesanstalt, Bundessortenamt und CHemische Industrie”. Allegedly, the abbreviation is said to unofficially represent the four companies that initially sponsored its development; Bayer, BASF, Ciba-Geigy, and Hoechst.

 

 

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Sowing the seeds of virology–entomology research collaborations to tackle African food insecurity

Success!

At the end of last month (June) I had the privilege of taking part in CONNECTEDV4. In case you’re wondering, this was a two-week training event at which a group of early career researchers from 11 African countries got together in Bristol, UK. Nothing so unusual about that, you may think.

Yet, this course, run by the Community Network for African Vector-Borne Plant Viruses (CONNECTED), broke important new ground. The training brought together an unusual blend of researchers: plant virologists and entomologists studying insects which act as vectors for plant disease, as an important part of the CONNECTED project’s work to find new solutions to diseases that devastate food crops in Sub-Saharan African countries.

The CONNECTED niche focus on vector-borne plant disease is the reason for bringing together insect and plant pathology experts alongside plant breeders. The event helped forge exciting new collaborations in the fight against African poverty, malnutrition and food insecurity.  ‘V4’ – Virus Vector Vice Versa – was a fully-funded residential course which attracted great demand when it was advertised. Places were awarded by competitive application, with funding awarded to cover travel, accommodation, subsistence and all training costs. For every delegate who attended, five applicants were unsuccessful.

The comprehensive programme combined scientific talks, general lab training skills, specific virology and entomology lectures and practical work and also included workshops, field visits, career development, mentoring, and desk-based projects. Across the fortnight delegates received plenty of peer mentoring and team-building input, as well as an afternoon focused on ‘communicating your science.’

New collaborations will influence African agriculture for years to come

There’s little doubt that the June event, hosted by The University of Bristol, base of CONNECTED Network Director Professor Gary Foster, has sown seeds of new alliances and partnerships that can have global impact on vector-borne plant disease in Sub-Saharan Africa for many years to come.

In writing this, I am more than happy to declare an interest. As a member of the CONNECTED Management Board, I have been proud to see network membership grow in its 18 months to a point where it’s approaching 1,000 researchers, from over 70 countries. The project, which derived its funding from the Global Challenges Research Fund, is actively looking at still more training events.

I was there in my usual capacity of extolling the virtues of entomology and why it is important to be able to identify insects in general, not just pests and vectors.  After all, you don’t want to kill the goodies who are eating and killing the baddies.  My task was to introduce the delegates to basic insect taxonomy and biology and to get them used to looking for insects on plants and learning how to start recognising what they were looking at. Our venue was the University of Bristol Botanic Gardens as the main campus was hosting an Open Day. This did impose some constraints on our activities, because as you can see from the pictures below, we didn’t have a proper laboratory.  The CONNECTED support team did, however, do a great job of improvising and coming up with innovative solutions, so thanks to them, and despite the rain, my mission was successfully accomplished.

Me in full flow, and yes, as is expected from an entomologist, I did mention genitalia 🙂

It’s genitalia time 🙂

A hive of activity in the ‘lab’

Collecting insects in the rain

The V4 training course follows two successful calls for pump-prime research funding, leading to nine projects now operating in seven different countries, and still many more to come. Earlier in the year CONNECTED ran a successful virus diagnostics training event in Kenya, in close partnership with BecA-ILRI Hub. One result of that training was that its 19 delegates were set to share their new knowledge and expertise with a staggering 350 colleagues right across the continent.

I thoroughly enjoyed the day, despite the rain, and was just sorry that I wasn’t able to spend more time with the delegates and members of the CONNECTED team. Many thanks to the latter for the fantastic job they did. The catering and venue were also rather good.

Project background

Plant diseases significantly limit the ability of many of Sub-Saharan African countries to produce enough staple and cash crops such as cassava, sweet potato, maize and yam. Farmers face failing harvests and are often unable to feed their local communities as a result. The diseases ultimately hinder the countries’ economic and social development, sometimes leading to migration as communities look for better lives elsewhere.

The CONNECTED network project is funded by a £2 million grant from the UK government’s Global Challenges Research Fund, which supports research on global issues that affect developing countries. It is co-ordinated by Prof. Foster from the University of Bristol School of Biological Sciences, long recognised as world-leading in plant virology and vector-transmitted diseases, with Professor Neil Boonham, from Newcastle University its Co-Director. The funding is being used to build a sustainable network of scientists and researchers to address the challenges. The University of Bristol’s Cabot Institute, of which Prof. Foster is a member, also provides input and expertise.

Did I mention that it rained? 🙂

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Some fantastic sculptures but a sad lack of insects

A couple of weeks ago my wife and Daughter #2 and I, took advantage of the late Bank Holiday Weekend to visit The Sculpture Park near Farnham.  For a Bank Holiday weekend the weather was pretty good, the sun decided to shine 😊

As the name suggests the park is set in a wooded valley with ponds, streams and small lakes, all of which are used to good purpose, the sculptures, most of which are for sale*, placed in appropriate locations.

At £10 each it was pretty good value; on the day we visited there were 850 sculptures on site.  You could, if you were so minded, walk around for free, but the £10 gives you access to a guide to the sculptures, including their prices* and directions to navigate the site.  Without the guide, you could have an enjoyable walk, but you would certainly miss a lot.  There is also an on-site shop if you want to spend more money and help the enterprise prosper 😊

I took a lot of photos, concentrating mainly on the natural history based themes, not of all of which I am going to share, but hopefully those I do will give you an idea of the site.

The site starts some distance before you reach the ticket office.  The sculptures are in a variety of materials and styles, stone, metal, fibre-glass and wood, abstract, odd and realistic.

Is this what the toads were heading towards?

The site makes great use of the natural features and there are many surprises lurking in bushes, around corners and above your head.

 Continuing with the watery theme

Amazing what you find lurking in the trees 🙂

and don’t forget to look above head height.

Perhaps the birds closer to the ground should be wary of the polar bear?

Woodland scenes

Waste not, want not, especially if you can sell it as art 🙂

Some very odd stuff – Listening for the boneshaker?

More phantasmagorical beings

These woodland denizens however, you might be forgiven for thinking are real

Beautiful

Even as an entomologist I thought this was great – Rutting stags in wood

And there were some insects, a couple of mantids ready to pounce on the unsuspecting visitor

Metallic arthropods

Invertebrates were, however, in very short supply, so even snails made it into my selection 🙂

 

Some days I feel like this 🙂

 

The Aurelian – way out of my price range 🙂

And to finish – a three dimensional play on words

 

It was a great place to visit, despite the dearth of invertebrate exhibits. Most of the sculptures were based on humans, which I seem not to have photographed 🙂  That said we did only see 420 of the sculptures, perhaps there were more invertebrates in the remaining 440! I somehow doubt it.  Going by this it would seem that sculptors, like the majority of the public, are institutionally vertebratist ☹ That said, French sculptor Edouard Martinet makes larger than life insect sculptures using old car parts and his work would certainly fit in well here.

A word of warning, parking is at a premium. We had to park a good ten minutes walk away from the entrance.  There there is a picnic area, but alas, no café,  and as you will need to spend a minimum of four hours to get around all the sculptures, it is well worth making a day of it and taking ample supplies of food and drink.

*prices ranging from a few hundred pounds to tens of thousands  :-0

 

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Pick and mix 18 – odds and ends from the web

The illegal orchid trade and its implications for conservation

On choosing titles for papers that actually tell you what they are about

When museums get it wrong, holiday booze or exhibit?

How earwing wings inspired a robotic gripper

What spiders can teach us about ecology

More bad news on the huge decline in numbers of insects and birds, this time in France

Manu Saunders is convinced that robotic bees will not be a success – what do you think?

An important report about the pollinator deficit from the Cambrigde Institute for Sustaianability Leadership

Great advice from Steve Heard on to rewrite your often-used methods and materials to avoid charges of plagiarism and copyright infringement

Are universities in loco parentis?

 

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Entomological classics – The D-Vac, Vortis and other motorised suction samplers

I think that all field entomologists of a certain age, certainly those of us over 60, are very familiar with the roar of a hot and smoky two-stroke engine in our ears, coupled with oily hands, aching shoulders and sometimes the smell of burning.  Some younger entomologists may also have had this joyful experience but I suspect they are in a minority among their peers.  The dreaded D-Vac, or to give it its more formal name, The Dietrick Vacuum Sampler was, for a long time, the entomological gold standard in the world of motorised insect sampling.

Part of the UEA cereal aphid research group demonstrating unsafe use of the D-Vac 😊

The D-Vac was the brain wave of an American entomologist Everett Dietrick, who at the time was working on the biological control of the alfalfa aphid, Therioaphis maculata (Dietrick et al., 1959). Their research was hampered by the time they were having to spend estimating the numbers of all the arthropods found in alfalfa fields; they needed a standard sampling method that would allow them to get good estimates of everything rather than using different, and thus time-consuming, methods for each arthropod group.  Essentially, think of a D-Vac as motorised sweep net.  The idea of replacing sweep netting with, in theory at any rate, a non-human biased method* was not new.  Hills (1933) in describing a motorised vacuum pipette for sampling leaf hoppers in beet points out that it is an adaptation of a device put together by a lab assistant in 1926.

The first motorised suction sampler? From Hills (1933) – The modified pipette collector

The first and even clumsier model of the D-Vac (Dietrick et al., 1959), but I suspect more pleasant to use than the back-pack version 🙂

The new improved back-pack version (Dietrick, 1961).  In my experience not very comfortable and on one occasion burst into flames while I was wearing it!

This could, with the aid of a handy pole be used to sample from the top of tall bushes. Not something I have tried so I can’t comment.

While searching for the earliest reference to a motorised suction device that was not a Pooter, I came across one invented a few years earlier than the D-Vac and used by the late, great Southwood of Ecological Methods fame among others, during his PhD (Southwood, 1955; Johnson et al., 1955), which I guess means that it was in operation well before 1955, although the actual full description was not published in a journal until a couple of years later (Johnson et al., 1957).

An earlier suction device used by the late great Southwood during his PhD (1955) (From Johnson et al., 1957).

Ensuring constancy of sample area (From Johnson et al., 1957)

It really does look like the vacuum cleaner we had when I was a kid 🙂

Amusingly, one of the early attempts to replace the D-Vac was actually based on this very vacuum cleaner (Arnold et al., 1973)

I was interested to see that the Johnson apparatus used a barrel to delineate the sample area, something advocated by my colleague Andy Cherrill (Zentane et al., 2016) when using his patent G-Vac, or “Chortis” as we jokingly call it 🙂

A couple of years after I started at Silwood Park and became involved in running the final year field course, a new and revolutionary insect suction sampler appeared on the market – The Vortis™ (Arnold, 1994).  This was lighter than the D-Vac, did not need a bag or net, easier to start, had an ‘idle’ function and mercifully did not have to be carried on your back 🙂

The Vortis™, overall a much pleasanter way to sample insects and generally much easier to start.  Invented in 1993 (Arnold, 1994).

 

Although not cheap, it was less expensive than the D-Vac. This became my suction sampler of choice although we kept our D-vac in good running order so that the students could compare the two samplers.  Surprisingly, few, if any, of the many users of The Vortis™ have done similarly, most just referring to the original description by Arnold (1994), e.g. Mortimer et al., (2002).  This is in marked contrast to the many studies that have compared the D-Vac with sweep-netting, pitfall trapping and swish net sampling (e.g. Johnson et al., 1957; Henderson & Whittaker, 1977; Hand, 1986; Schotzko & O’Keeffe, 1989; Standen, 2000; Brook et al., 2008). There is also a hand-held version of the D-Vac if anyone wants to compare that with the back-pack version.

Jan Dietrick poses with a D-Vac insect Vacuum in Ventura, Calif., on Monday, Oct. 16, 2006. (Photo by Bryce Yukio Adolphson/Brooks Institute of Photography ©2006) http://bryceyukioadolphson.photoshelter.com/image/I0000pmiujJcoGBI

This one looks easier to use than the backpack version but I have never seen it in operation. I am guessing that this was produced in response to the invention of the Vortis™.

Entomologists tend to have limited budgets when it comes to equipment, or anything for that matter, so it is not surprising that they soon came up with the idea of adapting garden leaf blowers into lightweight, inexpensive insect suction samplers (e.g. De Barro, 1991; Stewart & Wright, 1995). These are collectively known as G-Vacs (Zentane et al., 2016) presumably as a reference to their garden origin.

Andy Cherrill test driving his “Chortis” 🙂

 

My colleague Andy Cherrill has compared the catch composition of his own particular G-Vac with that of the Vortis™ and satisfied himself that it is as good as, if not better than the Vortis™ (Cherrill et al., 2017).  Importantly the cost of a G-Vac means that you can get, at least in the UK, six for the same price as a single Vortis™.

I leave you with two fun facts; the two largest motorised insect suction samplers that I have come across are both from the USA (where else?).  The first, mounted on the front of a truck, was used to collect parasites for the biological control of alfalfa aphids.

(1957) http://www.dietrick.org/articles/deke_truckvac.html  Used to collect parasites for mass release against alfalfa aphids.

 

The second, mounted on the front of a tractor was used to control Lygus bugs in strawberry fields in California (Pickel et al., 1994).  The driver/operator in the second example seems to be taking Health & Safety issues a bit more seriously than the team in the first 🙂

Lygus bug control in strawberries, California http://calag.ucanr.edu/Archive/?article=ca.v049n02p19

 

References

Arnold, A.J. (1994) Insect suction sampling without nets, bags or filters. Crop Protection, 13, 73-76.

Arnold, A.J., Needham, P.H. & Stevenson, J.H. (1973) A self-powered portable insect suction sampler and its use to assess the effects of azinphos methyl and endosulfan on blossom beetle populations on oil seed rape. Annals of Applied Biology, 75, 229-233.

Brook, A.J., Woodcock, B.A., Sinka, M. & Vanbergen, A.J. (2008) Experimental verification of suction sampler capture efficiency in grasslands of differing vegetation height and structure. Journal of Applied Ecology, 45, 1357-1363.

Cherrill, A.J., Burkhmar, R., Quenu, H. & Zentane, E. (2017) Suction samplers for grassland invertebrates: the species diversity and composition of spider and Auchenorrhyncha assemblages collected with Vortis (TM) and G-vac devices. Bulletin of Insectology, 70, 283-290.

De Barro, P.J. (1991) A cheap lightweight efficient vacuum sampler.  Journal of the Australian Entomological Society, 30, 207-20.

Dietrick, E.J. (1961) An improved backpack motor fan for suction sampling of insect populations.  Journal of Economic Entomology, 54, 394-395.

Dietrick, E.J., Schlinger, E.I. & van den Bosch, R. (1959) A new method for sampling arthropods using a suction collecting machine and modified Berlese funnel separator.  Journal of Economic Entomology, 52, 1085-1091.

Dietrick. E. J., Schlinger. E. I. & Garber, M. J. (1960). Vacuum cleaner principle applied in sampling insect populations in alfalfa fields by new machine method. California Agriculture January 1960, pp. 9-1 1

Doxon, E.D., Davis, C.A. & Fuhlendorf, S.D. (2011) Comparison of two methods for sampling invertebrates: vacuum and sweep-net sampling. Journal of Field Ornithology, 82, 60-67.

Hand, S.C. (1986) The capture efficiency of the Dietrick vacuum insect net for aphids on grasses and cereals. Annals of Applied Biology, 108, 233-241.

Henderson, 1. F. & Whitaker, T. M. (1977). The efficiency of an insect suction sampler in grassland. Ecological Entomology 2, 57-60.

Hills, O.A. (1933) A new method for collecting samples of insect populationsJournal of Economic Entomology, 26, 906-910.

Johnson, C.G., Southwood, T.R.E. & Entwistle, H.M. (1955) A method for sampling arthropods and molluscs from herbage by suction.  Nature, 176, 559.

Johnson, C.G., Southwood, T.R.E. & Entwistle, H.M. (1957) A new method of extracting arthropods and molluscs from grassland and herbage with a suction apparatus.  Bulletin of Entomological Research, 48, 211-218.

Mortimer, S.R., Booth, R.G., Harris, S.J. & Brown, V.K. (2002) Effects of initial site management on the Coleoptera assemblages colonising newly established chalk grassland on ex-arable land. Biological Conservation, 104, 301-313.

Pickel, C., Zalom, F.G.,  Walsh, D.B. & Welch, N.C. (1994) Efficacy of vacuum machines for Lygus Hesperus (Hemiptera: Miridae) control in coastal California strawberries. Journal of Economic Entomology, 87, 1636-1640.

Schotzko, D.J. & O’Keeffe, L.E. (1989) Comparison of sweep net., D-Vac., and absolute sampling., and diel variation of sweep net sampling estimates in lentils for pea aphid (Homoptera: Aphididae)., Nabids (Hemiptera: Nabidae)., lady beetles (Coleoptera: Coccinellidae)., and lacewings (Neuroptera: Chrysopidae). Journal of Economic Entomology, 82, 491-506.

Southwood, T.R.E. (1955). Some Studies on the Systematics and Ecology of Heteroptera.—Ph.D. thesis, University of London.

Standen, V. (2000) The adequacy of collecting techniques for estimating species richness of grassland invertebrates. Journal of Applied Ecology, 37, 884-893.

Stewart, A.J.A. & Wright, A.F. (1995) A new inexpensive suction apparatus for sampling arthropods in grassland.  Ecological Entomology, 20, 98-102.

Zentane, E., Quenu, H., Graham, R.I. & Cherrill, A.J. (2016) Suction samplers for grassland invertebrates: comparison of numbers caught using Vortis and G-vac devices.  Insect Conservation & Diversity, 9, 470-474.

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Pick and mix 5 – more links to ponder

Another set of links that interested me enough to read (and this week, watch) them all the way through.

 

Interesting (tongue-in-cheek) post about using Ribwort plantain as a garden flower

Jo Cartmell (@watervole) on how to turn your boring lawn into a beautiful wildflower meadow

Gretchen Vögel asks – Where have all the insects gone?

How ploughing and deep tillage methods are harming earthworms worldwide

We have been telling our students for years that one of the advantages of biological control compared with conventional use of pesticides is that prey are unlikely to evolve resistance to natural enemies.  Well, we were wrong – here is a story about a pest weevil that has done just that  – unfortunately behind a pay wall

Insects and ethics – Some very interesting points, but as much as I love insects which I do passionately, I am very happy, that ethically speaking, they are not classified as animals. Research would be impossible. That said, all insects in my garden live a free and happy life and are never knowingly killed, not even if they are on my bean plants 🙂

A nice article about photographing spiders and also mentions ethics

Here Markus Eichhorn writes about the questionable ethical standpoints of some otherwise reputable scientists from the last century

An interactive blog post about global crop diversity and eating habits – quite revealing, try it and see

An interesting and well produced short video that could be useful if you want to explain how sustainable management of tropical forests helps the planet and why you should only buy FSC certified products

 

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Small and frequently overlooked, but without them we could not exist

Without them, we would find the world a very different place, that is if we were still alive.  Yet very few people give them a thought, and then usually only to dismiss them or castigate them for impinging on our comfortable lives. Animals without backbones, the micro-flora and fauna, are what keep the world a place in which we can make a living.  Politicians however, and many others of our fellow travellers on this fragile planet, seem unaware of their importance.  Donald Trump rescinds environmental protection laws as if they are a hindrance to humankind rather than a boon, BREXIT politicians and their supporters in the UK extol the virtues of escaping from those silly EU environmental laws that prevent them from polluting our beaches and rivers and making our air unbreathable. We all need to take a step back and adjust our vision so that we can appreciate the little things that run the world and understand that despite our size, our abundance and our apparent dominance, that we too are a part of nature.

I and many others have written about this topic on many occasions but it is a message that bears repetition again and again.  I leave you with the passage that stimulated my latest rant and a few links to similar pieces.

“In terms of size, mammals are an anomaly, as the vast majority of the world’s existing animal species are snail-sized or smaller.  It’s almost as if, regardless of your kingdom, the smaller your size and the earlier your place on the tree of life, the more critical is your niche on Earth; snails and worms create soil, and blue-green algae create oxygen; mammals seem comparatively dispensable; the result of the random path of evolution over a luxurious amount of time.”

Elizabeth Tova Bailey  (2010)  – The Sound of a Wild Snail Eating

Here are a few links to give you food for thought and to inspire you to find more of the same.

Michael Samways  Small animals rule the world. We need to stop destroying them

E O Wilson (1987) The little things that rule the world

Gregory Mueller & John Schmidt (2007) on why we should know more about fungi

Robert May (2009) Ecological science and tomorrow’s world

Mark Gessner and colleagues (2010) on the importance of decomposers

Anders Dahlberg and colleagues (2010) on why we should conserve fungi

Anne Maczulak (2010) on the importance of bacteria

Me complaining about plastic and other environmental dangers

Me again, this time about conserving small things

Sorry, but me again, this time about appreciating nature

and from Gerald Durrell, who was a great inspiration to me through his various writings…

And finally, If you haven’t read this, then I can certainly recommend it:

Ehrlich, P.  & Ehrlich, A. (1981) Extinction, Random House, New York.

 

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Insects in flight – whatever happened to the splatometer?

I have been musing about extinctions and shifting baselines for a while now; BREXIT and an article by Simon Barnes in the Sunday Times magazine (3rd September 2016) finally prompted me to actually put fingers to keyboard.  I fear that BREXIT will result in even more environmental damage than our successive governments have caused already.  They have done a pretty good job of ignoring environmental issues and scientific advice (badgers) even when ‘hindered’ by what they have considered restrictive European legislation and now that we head into BREXIT with a government not renowned for its care for the environment I become increasing fearful for the environment. Remember who it was who restructured English Nature into the now fairly toothless Natural England, because they didn’t like the advice they were being given and whose government was it who, rather than keep beaches up to Blue Flag standard decided to reclassify long-established resort beaches as not officially designated swimming beaches?  And, just to add this list of atrocities against the environment, we now see our precious ‘green belt’ being attacked.

My generation is liable to wax lyrical about the clouds of butterflies that surrounded us as we played very non PC cowboys and Indians outside with our friends in the glorious sunshine.  We can also fondly reminisce about the hordes of moths that used to commit suicide in the lamp fittings or beat fruitlessly against the sitting room windows at night.  The emptying of the lamp bowl was a weekly ceremony in our house.  We also remember, less fondly, having to earn our pocket-money by cleaning our father’s cars, laboriously scraping the smeared bodies of small flies from windscreens, headlamps and radiator grilles on a Saturday morning.  A few years later as students, those of us lucky enough to own a car, remember the hard to wash away red smears left by the eyes of countless Bibionid (St Mark’s) flies, as they crashed into our windscreens.

splat-1

Typical Bibionid – note the red eyes; designed specially to make a mess on your windscreen 🙂 https://picasaweb.google.com/lh/photo/GBgoGHhRbj-eUUF9SxZ4s9MTjNZETYmyPJy0liipFm0?feat=embedwebsite

Are these memories real or are we looking back at the past through those rose-tinted glasses that only show the sunny days when we lounged on grassy banks listening to In the Summertime and blank out the days we were confined to the sitting room table playing board games?

We have reliable and robust long-term data sets showing the declines of butterflies and moths over the last half-century or so (Thomas, 2005; Fox, 2013) and stories about this worrying trend attract a lot of media attention. On a less scientific note, I certainly do not find myself sweeping up piles of dead moths from around bedside lamps or extricating them from the many spider webs that decorate our house.  Other charismatic groups, such as the dragonflies and damselflies are also in decline (Clausnitzer et al., 2009) as are the ubiquitous, and equally charismatic ground beetles (carabids) (Brooks et al., 2012).  But what about other insects, are they too on the way out?  A remarkable 42-year data set looking at the invertebrates found in cereal fields in southern England (Ewald et al., 2015) found that of the 26 invertebrate taxa studied less than half showed a decrease in abundance; e.g. spiders, Braconid parasitic wasps, carabid beetles, Tachyporus beetles, Enicmus (scavenger beetles), Cryptophagid fungus beetles, leaf mining flies (Agromyzids), Drosophila, Lonchopteridae (pointed wing flies), and surprisingly, or perhaps not, aphids.  The others showed no consistent patterns although bugs, excluding aphids, increased over the study period.  Cereal fields are of course not a natural habitat and are intensely managed, with various pesticides being applied, so are perhaps not likely to be the most biodiverse or representative habitats to be found in the UK.

But what about the car-smearing insects, the flies, aphids and other flying insects?  Have they declined as dramatically?  My first thought was that I certainly don’t ‘collect’ as many insects on my car as I used to, but is there any concrete evidence to support the idea of a decline in their abundance.  After all, there has been a big change in the shape of cars since the 1970s.

splat-2

Top row – cars from 1970, including the classic Morris 1000 Traveller that my Dad owned and I had to wash on Saturdays.

Bottom row the cars of today, sleek rounded and all looking the same.

 

Cars were  much more angular then, than they are now, so perhaps the aerodynamics of today’s cars filter the insects away from the windscreen to safety? But how do you test that?  Then I remembered that the RSPB had once run a survey to address this very point.  Sure enough I found it on the internet, the Big Bug Count 2004, organised by the RSPB.  I was very surprised to find that it happened more than a decade ago, I hadn’t thought it was that long ago, but that is what age does to you 🙂

splat-3

The “Splatometer” as designed by the RSPB

The idea, which was quite cool, was to get standardised counts of insect impacts on car number platesThe results were thought to be very low as the quote below shows, but on what evidence was this based?

“Using a cardboard counting-grid dubbed the “splatometer”, they recorded 324,814 “splats”, an average of only one squashed insect every five miles. In the summers of 30-odd years ago, car bonnets and windscreens would quickly become encrusted with tiny bodies.”  “Many people were astonished by how few insects they splatted,” the survey’s co-ordinator Richard Bashford, said.

Unfortunately despite the wide reporting in the press at the time, the RSPB did not repeat the exercise.  A great shame, as their Big Garden Birdwatch is very successful and gathers useful data.   So what scientific evidence do we have for a decline in these less charismatic insects?  Almost a hundred years ago, Bibionid flies were regarded as a major pest (Morris, 1921) and forty years ago it was possible to catch almost 70 000 adults in a four week period from one field in southern England (Darcy-Burt & Blackshaw, 1987).   Both these observations suggest that in the past Bibionids were very common.  It is still possible to pluck adult Bibionids out of the air (they are very slow, clumsy fliers) in Spring, but if asked I would definitely say that they are not as common as they were when I was a student.  But as Deming once said, “Without data, you’re just another person with an opinion.”  In the UK we are fortunate that a long-term source of insect data exists, courtesy of Rothamsted Research, the longest running agricultural research station in the world.  Data have been collected from a nationwide network of suction and light traps for more than 50 years (Storkey et al., 2016).   Most of the publications arising from the survey have tended to focus on aphids (Bell et al., 2015) and moths (Conrad et al., 2004), although the traps, do of course, catch many other types of insect (Knowler et al., 2016).  Fortuitously, since I was interested in the Bibionids I came across a paper that dealt with them, and other insects likely to make an impact on cars and splatometers (Shortall et al., 2009).  The only downside of their paper was that they only looked at data from four of the Rothamsted Suction Traps, all from the southern part of the UK, which was a little disappointing.

splat-4

Location and results of the suction traps analysed by Shortall et al. (2009).

Only three of the trap showed downward trends in insect biomass over the 30 years (1973-2002) analysed of which only the Hereford trap showed a significant decline.  So we are really none the wiser; the two studies that focus on a wider range of insect groups (Shortall et al., 2009; Ewald et al., 2015) do not give us a clear indication of insect decline.   On the other hand, both studies are limited in their geographic coverage; we do not know how representative the results are of the whole country.

What a shame the RSPB stopped collecting ‘splatometer’ data, we would now have a half-decent time series on which to back-up or contradict our memories of those buzzing summers of the past.

Post script

After posting this I came across this paper based on Canadian research which shows that many pollinators, possibly billions are killed by vehicles every year.  This reduction in insect numbers and biomass has also been reported in Germany.

References

Bell, J.R., Alderson, L., Izera, D., Kruger, T., Parker, S., Pickup, J., Shortall, C.R., Taylor, M.S., Verrier, P. & Harrington, R. (2015) Long-term phenological trends, species accumulation rates, aphid traits and climate: five decades of change in migrating aphids.  Journal of Animal Ecology, 84, 21-34.

Brooks, D.R., Bater, J.E., Clark, S.J., Montoth, D.J., Andrews, C., Corbett, S.J., Beaumont, D.A., & Chapman, J.W. (2012) Large carabid beetle declines in a United Kingdom monitoring network increases evidence for a widespread loss of insect biodiversity. Journal of Applied Ecology, 49, 1009-1019.

Clausnitzer, V., Kalkman, V.J., Ram, M., Collen, B., Baillie, J.E.M., Bedjanic, M., Darwall, W.R.T., Dijkstra, K.D.B., Dow, R., Hawking, J., Karube, H., Malikova, E., Paulson, D., Schutte, K., Suhling, F., Villaneuva, R.J., von Ellenrieder, N. & Wilson, K. (2009)  Odonata enter the biodiversity crisis debate: the first global assessment of an insect group.  Biological Conservation, 142, 1864-1869.

Conrad, K.F., Woiwod, I.P., Parsons, M., Fox, R. & Warren, M.S. (2004) Long-term population trends in widespread British moths.  Journal of Insect Conservation, 8, 119-136.

Darcy-Burt, S. & Blackshaw, R.P. (1987) Effects of trap design on catches of grassland Bibionidae (Diptera: Nematocera).  Bulletin of Entomological Research, 77, 309-315.

Ewald, J., Wheatley, C.J., Aebsicher, N.J., Moreby, S.J., Duffield, S.J., Crick, H.Q.P., & Morecroft, M.B. (2015) Influences of extreme weather, climate and pesticide use on invertebrates in cereal fields over 42 years. Global Change Biology, 21, 3931-3950.

Fox, R. (2013) The decline of moths in Great Britain: a review of possible causes. Insect Conservation & Diversity, 6, 5-19.

Knowler, J.T., Flint, P.W.H., & Flint, S. (2016) Trichoptera (Caddisflies) caught by the Rothamsted Light Trap at Rowardennan, Loch Lomondside throughout 2009. The Glasgow Naturalist, 26, 35-42.

Morris, H.M. (1921)  The larval and pupal stages of the Bibionidae.  Bulletin of Entomological Research, 12, 221-232.

Shortall, C.R., Moore, A., Smith, E., Hall, M.J. Woiwod, I.P. & Harrington, R. (2009)  Long-term changes in the abundance of flying insects.  Insect Conservation & Diversity, 2, 251-260.

Storkey, J., MacDonald, A.J., Bell, J.R., Clark, I.M., Gregory, A.S., Hawkins, N. J., Hirsch, P.R., Todman, L.C. & Whitmore, A.P. (2016)  Chapter One – the unique contribution of Rothamsted to ecological research at large temporal scales Advances in Ecological Research, 55, 3-42.

Thomas, J.A. (2005) Monitoring change in the abundance and distribution of insects using butterflies and other indicator groups.  Philosophical Transactions of the Royal Society B, 360, 339-357

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