Entomyopia and Entoalexia – two potentially life-threatening conditions

This post was stimulated by two recent events.  First, a conversation I had at a curry evening organised by the amateur band that my wife plays in.  My neighbour was a well-educated modern languages teacher in her early forties.  We discussed our various jobs and she evinced surprise that anyone would want to work with insects and even when I explained the myriad benefits of understanding insect biology and ecology to her in terms of food security, vector control, detritivores, integrated pest management, pollination etc., she was still unconcerned about the lack of training provision for entomology and the dwindling number of young entomologists in the population.  I also highlighted the growing disconnect between people and nature.  Her response was that it was just the way it was and that people had other interests now!  I was, despite the fact that I have bemoaned the lack of funding for invertebrate research and training for some time now, totally amazed and down-hearted.  The second event was when one of my entomological colleagues reported to me how shocked he had been, when describing the recent opening of our new entomology building at Harper Adams University to his next door neighbour, a retired engineer, that the neighbour expressed great surprise that anyone would want such a facility and why anyone would want to spend that amount of money to enable entomological research.

I have written before about my worries about the decline of interest in natural history and entomology (Leather & Quicke, 2009, 2010) but I feel that it is now well past time to do something urgently about this lack of understanding among the public, the educational establishment, funding councils and the government.  Not only is institutional invertebratism  (Leather, 2009, 2013) still alive and well but we now have two potentially life-threatening conditions that desperately need curing.

Entomyopia

noun

entomological short-sightedness

        • a condition in which insects are viewed either as pollinators or as nuisances
        • a lack of foresight or discernment as to the importance of entomology:  a narrow view of entomology

Entoalexia

noun

entomological blindness

        • a condition in which a person or organisation, is totally oblivious to the importance of entomology and insects

Insects - what insects

Symptoms

The closing of entomology departments and research groups

A reduction in the numbers of entomologists employed by universities and research institutions

An ageing population of practicing entomologists, many characterised by grey beards and spectacles

Lack of understanding by the general public about why the study of entomology is important to their well-being

A lack of teaching of invertebrate biology at secondary schools and at undergraduate level

A lack of government funding

A tendency for members of the general public to scream and/or flinch when insects enter their personal space

A tendency for members of the general public to kill insects when found in their personal space

A failure by the majority of the population to appreciate the beauty and wonder of insects

Investing hundreds of millions into medical research to keep people alive for longer (a good thing) without thinking about how the extra mouths are going to be fed without similar levels of investment in crop protection research (a very bad thing)

Funding in conservation and whole organism biology and ecology heavily biased towards “large charismatic mega-fauna”

Schoolchildren able to name the ten most endangered mammal species in the world but unable to recognize and name the ten most common insect species in their own country

 

Treatment

A concerted effort by all entomologists to explain to the general public, the educational establishment, funding bodies, the media and  government why we need urgently more entomologists and why the study of entomology is crucially important to our well-being.  I would go further than that and suggest that we need to redouble our outreach activities and to actively lobby those who hold the purse strings and those that represent us in government.  Yes, national entomological societies such as the Royal Entomological Society in the UK are doing much more to promote entomology than they used to but much more remains to be done.  The Amateur Entomologist’s Society  has, I have been reminded, also been active in this area for more than eighty years.  My message to all entomologists is act now before it is too late.

 

Prognosis

At the current level of investment  into treatment and cures, very gloomy.

 

Post script

As I was preparing this article Brigit Strawbridge published an impassioned plea to all of us to take more notice of the little things that run the world

http://www.beestrawbridge.blogspot.co.uk/2014/08/mass-insect-extinction-elephant-in-room.html
Post post script

I would be remiss if I did not point out that mycology, plant pathology and plant nematology are also extremely vulnerable and just as important to our well-being as entomology.

 

Post post post script

Entomyopia  is apparently not a new disease, shortly after posting this I came across this gem from 1882.

“No science is so generally slighted, ignored, and misunderstood as is Entomology.  Hysterical humanitarians, novelists, poets, political agitators, classical students, speak in terms of contempt or horror of the “fly-hunters””

Anonymous (1882) The Journal of Science, and Annals of Astronomy, Biology, geology, Industrial Architecture, Manufactures and Technology, 4, 208

 

References

Leather, S. R. (2009). Institutional vertebratism threatens UK food security. Trends in Ecology & Evolution 24: 413-414.

Leather, S. R. (2013). Institutional vertebratism hampers insect conservation generally; not just saproxylic beetle conservation. Animal Conservation 16: 379-380.

Leather, S. R. & Quicke, D. L. J. (2009). Where would Darwin have been without taxonomy? Journal of Biological Education 43: 51-52.

Leather, S. R. & Quicke, D. L. J. (2010). Do shifting baselines in natural history knowledge threaten the environment? Environmentalist 30: 1-2.

 

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Effervescent entomologists – MSc Entomology London Natural History Museum Visit 2015

Last Tuesday (February 4th 2015) I was roused from sleep by the strident tones of my mobile phone telling me that “It’s 5 ‘o’ clock, it’s time to get up”.   Just over an hour later I was standing outside a coach ticking names off my list as yawning MSc student entomologists, PhD students and entomological staff  sleepily settled  down for the four-hour journey to London* Happy Days Coach

Artistic licence – it was still dark when we left!  The name of the coach company is particularly apt.

 Just over four hours later we arrived outside the front of the Natural History Museum on Cromwell Road.NHM front

The front of the Natural History Museum London; when I was a child the beauty of the facade was obscured by soot and grime.

Making our way round to the Exhibition Road entrance, we were met by the legendary Max Barclay @coleopterist,  the Collections Manager for Coleoptera and Hymenoptera.  Pausing only to introduce the students to Charles Darwin and to allow them to take Max & Darwin

Max Barclay introduces Darwin to the students

photographs of the now Twittering Dippy the Diplodocus  @NHM_Dippy, Dippy

Dippy the Diploducus, shortly to be replaced by the Blue Whale skeleton. The blue whale skeleton in my opinion has two advantages over Dippy, first it is real, not a model and second it is actually my first ever biological memory, aged 3.

  we entered the first of our scheduled stops, the Coleoptera section. Beetles

Approximately 220 000 drawers of beetles

Here Max enthralled the students with  the magic of beetles large and small. Max enthralling

Max in full flow

We saw a very small  selection of Alfred Russel Wallace’s 8000+ collection, some of Darwin’s beetles and ARW beetles

A very small selection of Wallace’s collection.

some of the beetles collected by botanist Joseph Banks (as Max pointed out he appeared to be only able to collect large and showy specimens, whereas Darwin’s were much smaller and harder to identify.Bank's beetles

Bank’s beetles – large and showy

  We were also privileged to see a beetle collected by palaeaoanthropologist Louis Leakey whilst excavating hominid remains in the Olduvai Gorge. Max & Leakey's beetle

Max relating the story of how Louis Leakey thought he had found a fossil beetle.

 We then moved on to the Hymenoptera; unfortunately Gavin Broad was not available so we did not have the benefit of a specialist to enthrall us although we did see some interesting specimens such as this Tarantula Hawk Wasp.Pepsis

Pepsis heros – Tarantula Hawk

We then broke for lunch before meeting up with, in my opinion, the most entertaining Dipterist in the World, Erica McAlister, also known as @flygirlNHM. Erica and big flies

Erica with some rather large flies.

She showed us bot fly larvae from unexpected hosts, camels, elephants and rhinoceroses whilst regaling us with amusing and risqué anecdotes of fly mating behaviour.Camle bot flies

Camel bot fly larvae

Erica also showed us some large wax models of insects, my favourite being the model of the aphid, Myzus persicae, which was very good indeed and something I would dearly love to have in my possession.  Erica on the other hand was very keen on the model of a Drosophila mutant ;-)Erica & wax aphid

A very large aphid!

Then Erica led us into the depths of the museum to the Tank Room to look at some larger animals, or as Erica described them “The Big Pickles”. Tank room

Part of the Tank Room – lots of pickled fish

Some of the pickles were very big indeed.

Giant squid

A very big pickle – giant squid

After looking at some of the specimens that Darwin had collected whilst on the Beagle, we then went upstairs again, on the way looking at the famous cocoon from above, before we Long way down

Sideways view of the cocoon.

entered the world of the little pickles – spiders and their allies, some poisonous, some venomous.  There is a difference, check it out.Solifugid

A Camel spider; a Solifiguid, despite the common name, they are only very distantly related to spiders.

Scorpions

MSc Students and scorpions; big and relatively harmless, small and deadly (not the students). The gloves protect against the preservative, not the possibility of being bitten!

And then sadly, it was time to get back on the coach and make our way back to Shropshire and Harper Adams University.  A great day out, made particularly enjoyable by the obvious passion that Erica and Max have for their insects.  If you ever get the chance to see Max and Erica extolling the virtues of their pet beasties, make sure you do so.  Effervescent, ebullient, enthusiastic and energetic entomologists both.  I am  sure that I speak for all of us who made the trip when I say “Thank you Max” and “Thank you Erica”.

 

Post script

It was only when I was writing this blog post that I realised that this visit was exactly a year after our previous visit.  The other huge benefit of these visits is that it very important to let the students see that you can work as an entomologist in a museum without being male and grey-bearded ;-)  In which context it was very nice to bump into one of our ex-students, in fact one from the very first cohort of the MSc in Entomology after our move from Imperial College to Harper Adams (a story for a future post).

Minty

 

Footnote

*My wife (born in London) insists that it is up to London, but as a Yorkshireman this goes against the grain.  As far as I’m concerned London is down south, so for the sake of marital harmony I have gone for to London  ;-)

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The Scent of Fear – the aphid alarm pheromone

We are all familiar with the effects of epinephrine (adrenaline) and norepinephrine (noradrenaline) on us when placed in a position of stress, such as public speaking or even worse danger.  We flush, shake, our heart rate accelerates and many of us we begin to sweat profusely, thus visibly advertising our distress; sometimes embarrassingly so

Sweating nervously

 

if we have an antiperspirant  fail and happen to be wearing a dark shirt.

man_giving_speech

http://www.silkyskin.co.uk/blog/wp-content/uploads/2012/07/man_giving_speech.jpg

Those seeing these symptoms may feel a degree of sympathy for the victim, but do not usually flee the scene, although they may sometimes feel tempted to do so.

The case with aphids is very different.   Aphids, when perceiving a threat to their neighbours by a predator or parasite, flee the scene rapidly, by flight, if winged, on foot if not, or even by leaping from their host-plant to the ground below.  The pea aphid, Acyrthosiphon pisum walks away or drops from their plant (Clegg & Barlow, 1982) as does the rose-grain aphid, Metopolophium dirhodum (Larsen, 1988).  This may seem a risky move since it seems that about 10% of all aphids that fall from their host plant don’t manage to get back (Sunderland et al., 1986), but for a clonal organism the risk is obviously worth it.

So how does this communal fright and flight response come about?  Most aphids have a pair of siphunculi or cornicles at the rear of their abdomen.  These vary in size and shape, in some aphids being long and slender, in others short and stubby and in yet others reduced to a shallow indentation (pore) or in a few species, totally absent.

Siphunculi

The role of aphid siphunculi has been debated since the days of Linneaus and Reaumur who considered them to be the source of honeydew (Hottes, 1928).  Hottes himself in a comprehensive review of the various theories put forward for the function of the siphunculi, dismissed the defence theory of Busgen (1891) and plumped for an excretory role, although he did suggest that volatile substances were produced by the siphunculi in addition to the waxy visible drops.    By the middle of the last century it was generally accepted that the siphunculi were involved in defence, but in a purely physical way, in that the waxy exudate was used to deter or disable the attacking predators or parasites (e.g. Dixon, 1958; Edwards, 1966).  At about the same time, the chemical composition of the visible exudate was confirmed as being primarily triglycerides with myristic acid being the major fatty acid present (Strong, 1966).

Oleander Aphid- Milkweed-- Mark Bower - 1 - 1

Aphis nerii siphuncular exudate.  http://springfieldmn.blogspot.co.uk/2014/08/aphid-cornicles.html

 

 

Hawthorn-parsley aphid Dysaphis apiifolia producing sipuncular exudates whilst under attack by a parasitic wasp.  Many thanks to Tom Pope for permission to use this clip.

In 1968 an alarm pheromone was identified and isolated from the cotton stainer, Dysdercus intermedius (Calam & Youdeowei, 1968) so it was not surprising that attention should be focused on aphids, many of which show a similar group dispersive behaviour when a predator approaches them.   The aphid alarm pheromone (E)-β-farnesene was, however, not formally identified until  1972 (Bowers et al, 1971), although Maria Dahl had demonstrated the  previous year that a solution made from crushed aphids would cause an alarm response in other aphids of the same and different species (Dahl, 1971). Unsurprisingly, as during the 1970s and 1980s scientists from the USA were notorious for only citing papers written in English, Bowers et al. (1972), failed to cite her in their paper, instead citing two other American authors (Kislow & Edwards, 1972).

This discovery resulted in a flurry of papers from around the world as insect physiologists vied to be the first to isolate alarm pheromone from different aphid species (e.g. Weintjens et al., 1973; Montgomery & Nault, 1977; Wohlers, 1980).  There were also more ecological studies such as that examining the way alarm pheromone in ant-attended aphids enhances the relationship between them and their ant farmers (Nault et al., 1976) thus acting as a synomone (Nordlund & Lewis, 1976).  As time has gone on the interest in aphid alarm pheromone has remained unabated with new twists and surprises being discovered.  For example, as well as stimulating the escape response, the alarm pheromone also stimulates those surviving pea aphids to produce winged offspring thus facilitating future long-distance dispersal away from the predators (Kunert et al., 2005).  Aphid alarm pheromone can also act to help natural enemies find their aphid prey (e.g. Micha & Wyss, 1996), in this case acting as a kairomone.

The use of sex pheromones in integrated pest management is well established (Witzgall et al., 2010) and works very effectively in most cases. More recently, researchers at Rothamsted Research have courted controversy by trialing GM wheat that has been engineered to produce aphid alarm pheromone.  Many entomologists, including me, although finding the concept (Yu et al., 2012) interesting, doubt that it will work in a field situation.  I can certainly see a role for using alarm pheromones as an alternative to conventional chemical control of insect pests and it will be interesting to see if it will prove as effective as using sex pheromones.

 

References

Bowers, W. S., Nault, L. R., Webb, R. E. & Dutky, S. R. (1972). Aphid alarm pheromone: isolation, identification, synthesis. Science 177, 1121-1122.

Busgen, M. (1891)  Der Honigtau. Biologische Studien an Pflanzen und Pflanzenläusen.  Jenaische Zeitschrift für Naturwissenschaft, 25, 339-428

Calam, D.H. & Youdeowei, A. (1968) Identification and functions of secretion from the posterior scent gland of fifth instar larva of the bug Dysdercus intermedius. Journal of Insect Physiology, 14, 1147-1158

Clegg, J.M. & Barlow, C.A. (1982) Escape behaviour of the pea aphid, Acyrthosiphon pisum (Harris) in response to alarm pheromone and vibration. Canadian Journal of Zoology, 60, 2245-2252.

Dahl, M. L. (1971). Über einen Schreckstoft bei Aphiden. Deutsche Entomologische Zeitschrift 18, 121-128.

Dixon, A. F. G. (1958). The escape responses shown by certain aphids to the presence of the coccinellid Adalia decempunctata (L.). Transactions of the Royal Entomological Society London,110, 319-334.

Dixon, A. F. G. (1958). The protective function of the siphunculi of the nettle aphid, Microlophium evansi (Theob.). Entomologist’s Monthly Magazine, 94, 8.

Edwards, J.S. (1966) Defence by smear: supercooling in the cornicle wax of aphids.  Nature,  211, 73-74.

Hottes, F. C. (1928). Concerning the structure, function, and origin of the cornicles of the family Aphididae. Proceedings of the Biological Society of Washington 41, 71-84.

Kislow, C.J. & Edwards, L.J. (1972)  Repellent odour in aphids.  Nature, 235, 108-109.

Kunert, G., Otto, S., Rose, U.S.R., Gershenzon, J., & Weisser, W.W. (2005) Alarm pheromone mediates production of winged dispersal morphs in aphids. Ecology Letters, 8, 596-603.

Larsen, K.S. (1988) Responses of different age classes of the rose-grain aphid, Metopolophium dirhodum (Wlk.) to attack by a simulated predator.  Journal of Applied Entomology, 105, 455-459.

Montgomery, M. E. & Nault, L. R. (1977). Comparative response of aphids to the alarm pheromone, (E)-B-farnesene. Entomologia experimentalis et applicata 22, 236-242.

Micha, S.G. & Wyss, U. (1996)  Aphid alarm pheromone (E)-B-farnesene: a host finding kairomone for the aphid primary parasitoid Aphidius uzbekistanicus (Hymenoptera: Aphidinae).  Chemoecology, 7, 132-139

Nault, L. R., Montgomery, M. E. & Bowers, W. S. (1976). Ant-aphid associations: role of aphid alarm pheromone. Science 192, 1349-1351.

Nordlund, D. A. & Lewis, W. J. (1976). Terminology of chemical releasing stimuli in intraspecific and interspecific interactions. Journal of Chemical Ecology 2, 211-220.

Strong, F.E. (1966)  Observations on aphid cornicle secretions.  Annals of the Entomological Society of America, 60, 668-673.

Sunderland, K.D., Fraser, A.M., & Dixon, A.F.G. (1986) Field and laboratory studies on money spiders (Linyphiids) as predators of cereal aphids. Journal of Applied Ecology, 23, 433-447.

Wientjens, W. H., Lakwijk, C. J. M., & Van Der Marel, T. (1973). Alarm pheromone of grain aphids. Experientia, 29, 658-660.

Wohlers, P. (1980). Die fluchtreaktion der erbsenlaus Acyrthosiphon pisum Aausgelöst durch alarmpheromon und zusätzliche reize. Entomologia experimentalis et applicata 27, 156-168.

Witzgall, P., Kirsch, P. & Cork, A. (2010) Sex pheromones and their impact on pest management. Journal of Chemical Ecology, 36, 80-100.

Yu, X.D, Pickett, J., Ma, Y.Z., Bruce, T., Napier, J., Jones, H.D. & Xia, L.Q. (2012)  Metabolic engineering of plant-derived (E)-β-farnesene synthase genes for a novel type of aphid-resistant genetically modified crop plants.  Journal of Integrative Plant Biology, 54, 282-299.

 

Post Script

A brief guide to mones

An allomone is any chemical substance produced and released by an individual of one species that affects the behaviour of a member of another species to the benefit of the originator but not the receiver e.g. the ability of some plants to release aphid alarm pheromen and thus deter aphids form landing on them.

An apneumone is any substance produced by nonliving material that benefits a recipient species but is detrimental to a different species associated with the non-living material

A kairomone is a semiochemical, emitted by an organism, which mediates interspecific interactions in a way that benefits an individual of another species which receives it, without benefiting the emitter.  For a detailed critique of the term kairomone see Ruther et al. (2002).

A pheromone is a secreted or excreted chemical factor that triggers a social response in members of the same species. Pheromones are chemicals capable of acting outside the body of the secreting individual to impact the behaviour of the receiving individual e.g. alarm pheromones, food trail pheromones and sex pheromones.

A synomone is a substance produced by an individual of one species that benefits both the producer and the recipient which is of a different species.  An example is the release of chemical elicitors by plants that attract entomophagous insects when they are attacked by herbivores.

 

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Entomological classics – The Moericke (Yellow) Pan Trap

Most, if not all field entomologists, will have used Yellow pan traps and been delighted in a horrified sort of way, by the huge number of usually small and hard to identify insects that they attract.

Yellow pan trap borneo

Moericke (Yellow) Pan trap in use in the tropics.  http://oilpalmbiodiversity.com/news-update-2/

yellow-pan-and-gear

Moericke (Yellow) Pan trap in use in the far north.   http://thebuggeek.com/2010/07/20/my-life-in-the-north-so-far-the-halfway-point/yellow-pan-and-gear/  Many thanks to Crystal Ernst for permission to use this picture.

They are of course, designed to do just that and so as entomologists we should be happy that they are so good at their job.  The secret of their success lies in their colour, yellow, which is highly attractive to many flying insects, flies (Disney et al., 1982) and aphids (Eastop, 1955) being particularly attracted to them as are bees and wasps (Vrdoljak & Samways, 2012; Heneberg & Bogusch, 2014).  They are also attractive to thrips (Thysanoptera) (Kirk, 1984) and have long been the subject of many comparative studies (e.g. Heathcote, 1957), although the prize for one of the most elaborate and labour intensive studies involving pan traps must go to my friend and former colleague Thomas Döring (Döring et al., 2009) who ran an experiment using pan traps of seventy, yes seventy, different colours!  They are easy to deploy and range from expensively bought made-to-order versions to yellow plastic picnic plates, yellow washing up basins and even Petri dishes painted yellow.  They can be mounted on poles and sticks or just placed on the ground; to say that they are versatile is a bit of an understatement.

So who invented the pan trap?  I have of course given the name of the inventor away in the title of this article. They were invented surprisingly relatively recently, by the German entomologist Volker Moericke (Moericke, 1951), although I suspect that he used them some years before the publication of the paper.  These first pan or Moericke traps as we should call them, were made of tin, painted yellow, and mounted on three wooden sticks.  They were 22 cm in diameter and 6 cm deep and filled with a mixture of water and formaldehyde .  Moericke was working on the aphid Myzus persicae .  He was particularly interested in aphid vision and host location (Moericke, 1950). He observed that the aphids were able to distinguish between the red-yellow-green end of the spectrum and the blue-violet end.   This then stimulated him to try trapping aphids using coloured pan traps (Moericke, 1951).  He observed that the aphids were attracted to the yellow pan traps and behaved as if over a host plant resulting in them landing in the liquid from which they were unable to escape.  Although he noted that the traps were extremely effective at catching aphids he did not comment on what other insects he found in the traps.

Moericke trap

The first Moericke (yellow) Pan trap (from Moericke, 1951).

This simple, yet effective design has now become an essential part of the entomologist’s tool kit being used by field entomologists of every ilk working  across the world in every habitat.  They are truly an influential invention and worth of being named an entomological classic.  Given the wide usage of these traps and their remarkable efficacy I think that we should make every effort to acknowledge their inventor by calling their modern plastic counterparts Moericke Traps.

 

References

Disney, R.H.L., Erzinçlioglu, Y.Z., Henshaw, D.D.C., Howse, D., Unwin, D.M., Withers, P. & Woods, A. (1982) Collecting methods and the adequacy of attempted fauna surveys with reference to the Diptera.  Field Studies, 5, 607-621.

Döring, T., Archetti, M. & Hardie, J. (2009)  Autumn leaves seen through herbivore eyes.  Proceedings of the Royal Society B., 276, 121-127.

Eastop, V.F. (1955)  Selection of aphid species by different kinds of insect traps.  Nature, 176, 936

Heathcote, G.D. (1957) The comparison of yellow cylindrical, flat and water traps, and of Johnson suction traps for sampling aphids.  Annals of Applied Biology, 45, 133-139.

Heneberg, P. & Bogusch, P. (2014)  To enrich or not to enrich?  Are there any benefits of using multiple colors of pan traps when sampling aculeate Hymenoptera?  Journal of Insect Conservation, 18, 1123-1136

Kirk, W.D.J. (1984)  Ecologically selective traps.  Ecological Entomology, 9, 35-41

Moericke, V. (1950)  Über das Farbsehen der Pfirsichblattlaus (Myzodes persicae Sulz.).  Zeitschrift für Tierpsychologie, 7, 265-274.

Moericke, V. (1951)  Eine Farbafalle zur Kontrolle des Fluges von Blattlausen, insbesondere der Pfirsichblattlaus, Myzodes persicae (Sulz.).  Nachrichtenblatt des Deutschen Pflanzenschutzdiensten, 3, 23-24.

Vrdoljak, S.M. & Samways, M.J. (2012)  Optimising coloured pan traps to survey flower visiting insects.  Journal of Insect Conservation, 16, 345-354

 

Post script

Many thanks to those readers who supplied me with Moericke’s first name, which in the original version of this post was lacking.

 

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A Roundabout Look at 2014 – Another year of Not Forgetting the Roundabouts

Although I have recently written about my two years of blogging and tweeting, I couldn’t resist the temptation to begin 2015 with a quick round-up of 2014 on Don’t Forget the Roundabouts.

Hook of Holland

A gratuitous roundabout – collected summer 2014 Hook of Holland on our way back from our summer holiday.

According to the statistics provided by WordPress, I reached 145 countries (112 in 2013), and received about 24 000 views (14 349 in 2013).

Countries 2014

Once again my most viewed post was Not All Aphids are Vegans with my post about saving UK plant sciences in second place.  I continue to be surprised at how many people appear (or think that they have) to be bitten by aphids.  In all my years of working with aphids I have only been probed (bitten, stung) twice.  Looking at the distribution of hits for the post though it does seem to reflect the times of year when aphids are most active.

Vegan aphid stats 2014

This post is obviously filling a need as the number of views has more than doubled since last year.

An innovation for 2014 was my series on entomological classics, mainly equipment, but I also included Southwood’s 1961 paper under that heading.  This coming year I will continue much as before, posts about aphids, more entomological classics (look out for yellow water traps next), the odd rant or two and a new series on those scientific papers and authors that have really inspired me over the years.

I guess my biggest accolade this year was having my blog praised by a professional science journalist, @GrrlScientist, who in her plenary talk at the recent joint BES/SFE meeting in Lille made me blush terribly.

I would really like to have more comments and interactions via the blog; at the moment Twitter is where most exchanges occur.  It would also be nice if everyone who followed me on Twitter read my blog!  That said I must acknowledge my most frequent commenters and bestowers of likes.  These are Emily Scott http://adventuresinbeeland.com/, Jeff Ollerton http://jeffollerton.wordpress.com/, Amelia from A French Garden, and Emma Tennant http://missapismellifera.com/.  I am also very grateful to the 135 people who subscribe to my blog.  Many thanks to you all for your interest and kind words.

A Prosperous and Happy New Year to you all.

Happy New Year

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A Christmas Aphid

A few weeks ago I was contacted by a researcher from the One Show.  They were interested in the possibility of doing a festive piece about what people bring into the house with them on Christmas trees with the idea that George McGavin would shake a Christmas tree over a piece of white paper and tell the audience all about the insects that fell out;  a typical media “how gross nature” is piece.

The researcher was somewhat disappointed when I told her that being winter  that there would be relatively little hiding in the tree, especially if it was a commercially reared cut tree bought from a garden centre or other retail outlet.  Cut Christmas trees in the UK tend to be harvested from October onwards so the chances are that your tree has lain about for at least a month before you bring it into your house and by that time, any sensible winter active herbivore has long departed for fresher trees.  Although conifer trees have a large number of insect species associated with them, most of them spend the winter either off the tree or as inactive eggs hidden under the bark or as eggs actually laid inside the needles e.g. the pine sawfly Neodiprion sertifer.  You would probably find a few opportunistic spiders and possibly some mites and bark lice, but not much else unless you had a potted tree or one that had only recently been felled.  The other thing that would influence what you would find is of course what species of tree you had bought.  Gone are the days when the Christmas tree and Norway spruce (Picea abies) were one and the same.  I guess my caveating and pessimistic reply proved too much for the researcher as I never heard back from her.

The one insect I had waxed lyrical about was of course an aphid, the green spruce aphid, Elatobium abietinum to be precise.   There are a number of aphid species that make a living on spruce trees, some of them quite large and spectacular such as the greater black spruce aphid, Cinara piceae, but like most aphids, they overwinter as eggs (Leather, 1992).

Cinara_piceae_aptera_on_Picea_abies_at_Selwyn_Wood

The greater black spruce aphid, Cinara piceae (Photograph courtesy of http://influentialpoints.com/Gallery/Aphids_on_spruce_Picea_in_Britain.htm)

The green spruce aphid, E. abietinum or Elatobium as it is commonly known, (there is only one species in the genus), overwinters in the UK and most other parts of the world, as an adult or immature stage (nymph) (Nicol et al., 1998).

The adult is small, green and inconspicuous, and quite difficult to see unless you are actually looking for them.

Elatobium and nymphs

The green spruce aphid, Elatobium abietinum and nymphs.

The green spruce aphid is a native of Europe and normally attacks Norway spruce.  They avoid current year needles as these tend to be distasteful to them (the chemistry of young spruce needles is pretty nasty and makes them unsuitable hosts for the aphids) and feed on the previous year and older needles.  Spruce needles, even older ones, are not particularly nutritious, so the aphid injects a toxic material in its saliva that makes the needles more nutritious by encouraging nitrogen mobilisation (Kloft & Erhardt, 1959).  Their populations build up during the spring and towards the end of May and beginning of June, they take flight and the trees seem relatively free of aphids (Bevan, 1966).  As they are so small, they are most obvious after they have gone, either by the damage they cause, premature senescence of the needles as shown in the photograph above, premature needle drop or by the presence of a large number of ladybird larvae.  When I worked for the Forestry Commission as an entomologist, I quite often received phone calls from distressed foresters who had sprayed the blue beetles damaging their spruce trees!

Although they are difficult to find during the summer months they are still there; this summer collapse of singe-host aphids is quite common (Karley et al., 2004).  In the autumn,  Elatobium populations begin to build up and as they do not overwinter as eggs, they are able to continue reproducing through the winter months (Powell & Parry, 1976). Sitka spruce, Picea sitchensis, the most commonly grown conifer in the UK, is a native of North America and as such has very low resistance to Elatobium and displays an almost hypersensitive response to the toxic saliva produced by the aphid.

If it is a particularly mild winter then the spruce trees are likely to show severe signs of damage by June and July.  After several mild winters spruce trees may end up with only current year needles present, which has a severe effect on their growth and appearance.

Elatobium damage needles

Branches of Sitka spruce with only current year needles present after a severe Elatobium abietinum infestation

Elatobium damage trees

Sitka spruce trees showing discoloured needles after attack by Elatobium abietinum.

It may be small, inconspicuous and not worth a TV appearance, but  Elatobium abietinum is now a pest with a world-wide distribution and an international reputation.

References

Bevan, D. (1966). The green spruce aphis Elatobium (Neomyzaphis) abietinum Walker. Scottish Forestry 20, 193-201.

Karley, A. J., Parker, W. E., Pitchford, J. W. &Douglas, A. E. (2004). The mid-season crash in aphid populations: why and how does it occur? Ecological  Entomology 29, 383-388.

Kloft, W. & Ehrhardt, P. (1959). Unterschungen uber Saugtatigkeit und Schadwirkung der Sitkafichtenlaus, Liosomuphis abietina (Walk.), (Neomyzaphis abietina Walk.).  Phytopathologie Zeitzschrqt 35, 401 – 410.

Leather, S. R. (1992). Aspects of aphid overwintering (Homoptera: Aphidinea: Aphididae). Entomologia Generalis 17, 101-113.

Nicol, D., Armstrong, K. F., Wratten, S. D., Walsh, P. J., Straw, N., Cameron, C. M., Lahmann, C. & Frampton, C. M. (1998). Genetic diversity of an introduced pest, the green spruce aphid Elatobium abietinum (Hemiptera: Aphididae) in New Zealand and the United Kingdom. Bulletin of Entomological Research 88, 537-543.

Powell, W. & Parry, W. H. (1976). Effects of temperature on overwintering populations of the green spruce aphid, Elatobium abietinum.  Annals of Applied Biology 82, 209-219.

Sullivan, C.R. (1965) Laboratory and field investigations on the ability of eggs of the European Pine Sawfly, Neodiprion sertifer (Geoffroy) to withstand low winter temperatures.  Canadian Entomologist, 97, 978-993

 

Postscript

During the 1980s when ‘Acid Rain’ was very much in the news, Elatobium damage was often mistaken as a symptom of acid rain in the UK.

 

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Vive La France! The BES crosses La Manche

This year the AGM of the British Ecological Society  (BES) was a joint affair with the Société Française d’Écologie (SFE) and was held in Lille in northern France just over an hour away from London by Eurostar.  Given our love of France and in my wife’s case, Christmas markets, there was no way I was not going to attend this landmark meeting especially as the BES were willing to pay my registration fee in recognition of my role as an Associate Editor of the Journal of Animal Ecology.   My mother-in-law is also a keen fan of Christmas markets so she decided to come along and keep Gill company.

We left London on a later train than originally planned (strike action in Brussels) and arrived in Lille mid –afternoon Monday to find that our hotel was a good 4 km away from the railway station and almost as far away from the Grand Palais where the conference was being held.  Luckily my mother-in-law, although almost 86, is very spry and took the longish walk in her stride.  We eventually found the hotel, on the way being amused by an Irish pub with a very non-Irish name ;-)

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An unusual name for an Irish Pub

Being a Monday in France, not much was open but we eventually found somewhere to eat for a reasonable price, and amusingly were served by an English waiter!

As the conference registration didn’t start until Tuesday evening we spent most of the day sight-seeing and bumping into fellow delegates.

 

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The Christmas market was, however, somewhat disappointing, especially for those of us who were at the BES Birmingham meeting a couple of years ago.

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The very small Christmas Market

The damp weather was also a bit off-putting.  This was when I started to regret my decision to opt for a comfortable well-worn pair of Desert Boots with holes in the soles instead of a new pair.

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Wet, cold feet

The state of my feet inspired me to tweet an appropriate Haiku ;-)

 

Wet Pavements in Lille

Desert boots are great,

except when soles are holey;

then rain means wet feet

 

The BES and SFE did a great job – a very full programme kept us occupied from Wednesday 10th until late afternoon of Friday 12th December.  (Gill and my mother-in-law managed to get to Brussels and Arras for their Christmas markets).  My only gripe was that because it was such a popular meeting (over 1100 delegates) that there were a huge number of sessions (62) so I missed a lot of talks that I wanted to hear.  This is why in some ways I much prefer smaller conferences such as the Royal Entomological Society annual meetings where there are generally only two parallel sessions.  I have long ago given up trying to session- hop, so confined myself to the plenaries and complete sessions such as the Agricultural Ecology, Pest & Pesticides session, where one of my favourite talks was given by Victoria Wickens from the University of Reading on local and landscape effects on aphids and their natural enemies; she was supported in the audience by her identical twin, Jennifer (also a PhD student at Reading and who spoke later in the Plant-Pollinator Interactions session).  I first meet Jennifer and Victoria at the BES AGM in Leeds when they were MSc students and student helpers.  It was only towards the end of that conference that I realised that there were actually two of them ;-)

With careful planning I managed to fit in the Urban Ecology session, the Ecology & Society session, the symposium session on plant-insect-microbe interactions, and a session on herbivory.  There were a lot of really good talks and I learnt a lot. I made sure that I attended the Friday morning talk by Grrl Scientist who spoke about the use of social media and crowd funding in ecology.  I was somewhat embarrassed (and flattered) to have my blog publicly cited as an example of what other ecologists should be doing.  It was lucky that it was dark in the auditorium as I was blushing rather a lot.

The influence of the SFE was definitely felt; the catering was much, much better than we normally get at the normal BES meetings and it was great to see so many French ecologists.

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and the free beer at lunch time was a welcome innovation that went down very well with the English delegates ;-)

Free beer

The organisers of the meeting next year in Edinburgh must be feeling somewhat nervous ;-)

 

Very many thanks to the BES and SFE and their local organisers for putting on such a splendid meeting; a veritable scientific and gastronomic delight.

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The infamous Desert boots – back home and ready to be  put to rest!

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