Not all aphids grow up to be aphids – the enemy within

It has been said that if aphids had their own way and unlimited resources the world as we know it would be 149 km deep in the cute little beasts (Harrington, 1994 ). Last year I wrote about how predators that feed on aphids, although useful, don’t really cut the mustard when it comes to keeping them in check and suggested that their host plants played a major role in keeping aphids from taking over the World.  While they do play an important part in keeping aphid populations under control, and are aided and abetted by aphid specific predators, there are, however, some much more efficient aphid-specific natural enemies out there.  They may be less conspicuous than the brightly coloured ladybirds that we often see munching their way through aphid colonies; public perception of their name may make people wince, but these beautiful and graceful creatures make sure that our appetite for salads and exotic vegetables out of season is satisfied safely and efficiently.  Their life cycles rival that of their prey, or should that be hosts, and entomologists fondly imagine that the film Alien was inspired by them 😊

I am, of course, talking about parasitic wasps, or parasitoids as they are more commonly known.  They are called parasitoids because unlike true parasites which generally speaking keep their hosts alive, insect victims of these wasps will, if successfully parasitized, die well before their non-parasitized relatives. In case you were wondering, the term parasitoid was coined by the Finnish Hemipterist, Odo Reuter (1913).  Aphids are not the only insects that are attacked by parasitoid wasps. The action of insect parasites has been known about for over two hundred years.  Erasmus Darwin, grandfather of the more famous Charles, noted that Ichneumonid wasps parasitised cabbage white butterfly caterpillars and so should be encouraged by gardeners (Darwin, 1800).  This is not the only early mention of parasitic insects in this context; Wheeler (1928), points out that back in the 1850s, two Italian entomologists, Camillo Rondani and Vittore Ghiliana also suggested the use of parasitic insects as biological control agents.  Aphid pests of glasshouse crops originally controlled mainly by predators (van Lenteren & Woets, 1988) are now routinely controlled by the application of commercially produced Braconid and Chalcid wasps (Boivin et al., 2012; van Lenteren, 2012).

Three commonly used aphid parasitoid biological control agents in action. Images from http://biologicalservices.com.au/products/aphelinus-2.html and https://www6.inra.fr/encyclopedie-pucerons/Especes/Parasitoides/Braconidae-Aphidiinae/Praon-volucre

When people think of Hymenoptera, they tend to think of bees, Vespid wasps and ants as being the most important and abundant.  They are very much mistaken.  The Parastica, or parasitoid wasps, are, by a huge margin, the most speciose and abundant section of

Parasitoids clearly dominate the Hymenopteran fauna of the British Isles (Many thanks to Natalie Dale-Skey of the NHM for permission to use this).

the Hymenoptera both in the UK and elsewhere

In the tropics the parasitoids are even more dominant. Data from Gaston et al., (1996).

Once parasitized, the egg(s), unless they are encapsulated by the aphid ‘immune’ system, hatch and begin to feed on the internal tissues of their, presumably, unsuspecting aphid host.  The parasitoid larvae avoid feeding on vital parts of the aphid, so that it can continue to grow and develop and provide food for the parasitoid, until the parasitoid is ready to pupate. Once the parasitoid is ready to pupate it delivers the coup de grace putting the aphid out of its misery and allowing the formation of the ‘mummy’ in

The three most common types of aphid mummies.  Images from http://resources.rothamsted.ac.uk/science-stories/aphids-mummies-and-cadavershttp://biologicalservices.com.au/products/aphelinus-2.html and https://farm1.static.flickr.com/327/18532751584_becc0e56e9_b.jpg respectively.

which the parasitoid completes its development before sawing its way out to emerge as a winged adult ready to seek out new hosts, leaving a characteristic neat circular hole in mummy case. In case you were wondering why the mummy of Praon volucre looks like it is sitting on a plate, this because, unlike the other aphid parasitoids, the final instar cuts its way out of the bottom of the aphid and spins its cocoon externally underneath the remnants of the aphid, hence the ‘plate’ (Beirne, 1942).

And out she comes; emerging parasitoid – http://resources.rothamsted.ac.uk/science-stories/aphids-mummies-and-cadavers

 

Lysiphelbus testaceipes  Photo by J.K.Clark, University of California Statewide IPM Project

Once an aphid, now a hollow mummy; note the neat emergence holes.  Aphid parasitoids are very much tidier than the parasitic lifeform in the classic film Alien 🙂

Another aspect of their life style that makes parasitoids a breed apart from true parasites, is that as well as using aphids as egg laying sites for their larvae, the adults like to snack on them every now and then to help mature more eggs and to keep up their energy levels; sometimes quaintly described as predatism (Flanders, 1953).  Although the parasitoids can make feeding attacks at any time, they appear to feed first and then start laying their eggs (e.g. Collins et al., 1981).

Parasitoids are widely used as biological control agents in glasshouses and other protected environments as they are generally regarded as being more effective than predators (Debach & Rosen, 1991), although there is some support that generalist predators can play a significant part in biological control in the wider environment (Symondson et al., 2002; Gontijo et al., 2015).  That said, aphid parasitoids seem to be fairly host specific in that commercial companies offer specific parasitoid mixtures to control different aphid pest species e.g.  https://www.koppert.com/pests/aphids/product-against/aphipar/ [Note this is NOT an endorsement]. In fact it has been suggested that the relationship between aphids and their parasitoids can be used to clarify aphid taxonomic relationships (Mackauer, 1965). On the other hand, there are very few examples of monophagous aphid parasitoids, most being described as oligophagous (Stary & Rejmanek, 1981).   So given that there is a fair bit of evidence that the parasitoids attacking aphids do show some discrimination in their choice of hosts, how do they find them?

Parasitoids in general were originally thought to be “possessed of an unerring instinct that guided them in their search for hosts” but Cushman (1926) rebutted this idea pointing out that actually the parasitoids first home in on the habitat or food plant that their host lives in and then search for their host (Laing, 1937).   The parasitoids referred to by Cushman and Laing, are however, not parasitoids of aphids, attacking lepidopteran leaf miners and carrion feeding flies respectively, so you might perhaps think that aphid parasitoids could have a different strategy. Although habitat selection by parasitoids of lepidopteran larvae (Thorpe & Caudle, 1938) and sawfly larvae (Monteith, 1955), using olfactory cues of their host’s food plant was confirmed readily easily and early on, the situation with aphids was less clear cut. Manfred Mackauer for example, suggested that aphid parasitoids might be using visual cues, such as leaf deformities or damage to find their aphids hosts (Mackauer, 1965).  The breakthrough came when three cabbage loving entomologists from the USA used an olfactometer to first show that the Braconid parasitoid Diaeretiella rapae, responded positively to the odour of collards (what we in the UK call spring greens) and second to show a very strong preference for them to lay their eggs in the aphid Myzus persicae when it was feeding on crucifers rather than other host plants.  They attributed this to the presence of mustard oil, the chemical that gives cabbages their distinctive taste and suggested that once the aphid host plant was found then the parasitoids used visual cues to find their aphid victims (Read et al., 1970).  Six years later it was firmly established that parasitoids in general used olfactory cues both to locate the habitat of their host (long-range) and then a short-range to find and confirm the identity (contact chemicals) their insect hosts (Vinson, 1976).

It was thought that the aphid parasitoids were chemically ‘conditioned’ during their larval life within the aphid feeding on a host plant and that this influenced their adult host preferences (e.g. Sheehan & Shelton, 1989; Wickremasinghe & Van Emden, 1992).  These, and other similar results, seemed to support the Hopkins host selection principle (Hopkins, 1917) which states that adult preferences are learnt as larvae.  A very neat experiment by van Emden et al., (1996) proved this hypothesis wrong. They transferred aphid mummies from the plant on which they had been parasitized on to another host plant and this changed the preference of the emerging adult, seeming to suggest that this was how aphid parasitoids developed their host preferences.  Now comes the neat, and very tricky part; if however, the parasitoid pupae were removed (very carefully) from the mummy case and reared to adulthood in the absence of a host plant or mummy and kept in a glass tube, the emerging adults showed no preference for particular host plants, clearly showing that adult preferences were  not determined during larval development but ‘conditioned’ by exposure to the external skin of the aphid mummy on emergence (van Emden et al., 1996).  Using aphids reared on an artificial diet (Douloumpaka & van Emden, 2003) showed that the it was very likely that the mother parasitoid leaves a chemical cue in or around the egg(s) she lays and that this is later incorporated into the silk of the parasitoid pupa, thus inducing the host preference seen as an adult.

An additional twist to the story is that male and female parasitoids differ in their responses to odours.  Both sexes of Aphidius uzbekistanicus and A. ervi, parasitoids of cereal aphids in the UK, respond to plant odours, but only females respond to aphids (Powell & Zhi-Li, 1983).  Males of both species are, however, attracted to the odours of their respective females, suggesting the existence of a sex pheromone. The existence of a sex pheromone in aphid parasitoids had been suggested a few years earlier when it was shown that male D. rapae attempted to copulate with filter paper that had had female abdomens crushed on them (Askari & Alisha, 1979).  The existence of sex pheromones in aphid parasitoids has now been shown in several species (e.g. Decker et al., 1993; McNeil & Broduer, 1995).  Strangely, female parasitoids also respond to sex pheromones, but in their case, the sex pheromones of aphids.  It turns out that they ‘parasitise’ aphids in more than one way, they home in on their prey using the aphid sex pheromone and this enables them to find a suitable overwintering host (Hardie et al., 1991).  At other times of the year they also use other aphid indicators; several studies have shown that parasitoids use the presence of aphid honeydew to help them find their hosts (Budenberg, 1990; Bouchard & Cloutier, 1984; Gardner & Dixon, 1985).

Predators of aphids such as ladybirds use chemical markers to warn other ladybirds that they have laid eggs near aphid colonies, thus reducing the chances of cannibalism and competition (e.g. Oliver et al., 2006). Given that the eggs of aphid parasitoids are laid internally, they are in effect invisible, it would make sense if the parasitoids ‘marked’ their hosts in some way to avoid other parasitoids laying their eggs in an already parasitized aphid, superparasitism.  Sure enough, there is some evidence that some adult parasitoids can recognise aphids that already have larval parasitoids developing inside them although they don’t seem to be able to consistently recognise already parasitized aphids until some hours afterward (e.g. Cloutier et al., 1984).  In some cases, it seems that it is the aphid herself that prevents superparasitism by reacting more aggressively towards parasitoids after being attacked once (Gardner & Dixon, 1984) and also by the presence of dried siphuncular secretions on the aphid’s skin (Outreman et al., 2001).  The waxy secretion had an effect for up to a day or so after which the internal changes caused by the developing parasitoid larvae were enough to deter further oviposition attempts.

It is a good thing for the poor aphids that they have such a high reproductive rate, or they would truly be in dire straits.  On the other hand, as exemplified by the words of Jonathan Swift (1733),

“So naturalists observe, a flea
Has smaller fleas that on him prey;
And these have smaller still to bite ’em,
And so proceed ad infinitum

there are parasites of parasitoids, the hyperparasites, that help keep the numbers of parasitoids under control, and thus, indirectly, help aphids remain relatively abundant.

 

References

Askari, A. & Alisha, A. (1979) Courtship behavior and evidence for a sex pheromone in Diaeretiella rapae (Hymenoptera: Braconidae), the cabbage aphid primary parasitoid. Annals of the Entomological Society of America, 72, 79-750.

Beirne, B.P. (1942) Observations on the life-history of Praon volucre Haliday (Hym.: Braconidae), a parasite of the mealy plum aphis (Hyalopterus arundinis Fab.). Proceedings of the Royal Entomological Society of London, Series A, General Entomology, 17, 42-47.

Boivin, G., Hance, T. & Brodeur, J. (2012) Aphid parasitoids in biological control.  Canadian Journal of Plant Science, 92, 1-12.

Bouchard, Y. & Cloutier, C. (1984) Honeydew as a source of host-searching kairomones for the aphid parasitoid, Aphidius nigripes (Hymenoptera: Aphidiidae).  Canadian Journal of Zoology, 62, 1513-1520.

Budenberg, W.J. (1990) Honeydew as a contact kairomone for aphid parasitoidsEntomologia experimentalis et applicata, 55, 139-148.

Cloutier, C., Dohse, L.A. & Bauduin, F. (1984) Host discrimination in the aphid parasitoid Aphidius nigripes. Canadian Journal of Zoology, 62, 1367-1372.

Collins, M.D., Ward, S.A., & Dixon, A.F.G. (1981) Handling time and the functional response of Aphelinus thomsoni, a predator and parasite of the. Journal of Animal Ecology, 50, 479-487.

Cushman, R.A. (1926) Location of individual hosts versus systematic relation of hots species as a determining factor in parasitic attack. Proceedings of the Entomological Society of Washington, 28, 5-6.

Darwin, E. (1800) Phytologia: or The Philosophy of Agriculture and Gardening. P. Byrne, Grafton Street, London.

Debach, P. & Rosen, D. (1991) Biological Control by Natural Enemies, Cambridge University Press, New York.

Decker, U.M., Powell, W. & Clark, S.J. (1993) Sex pheromone in the cereal aphid parasitoids Praon volucre and Aphidius rhopalosiphiEntomologia experimentalis et applicata, 69, 33-39.

Douloumpaka, S. & van Emden, H.F. (2003) A maternal influence on the conditioning to plant cues of Aphidius colemani Viereck, parasitizing the aphid Mysuze persicae SulzerPhysiological Entomology, 28, 108-113.

Flanders, S.E. (1953) Predation by the adult Hymenopteran parasite and its role in biological control. Journal of Economic Entomology, 46, 541-544.

Gardner, S.M. & Dixon, A.F.G. (1984) Limitation of superparasitism by Aphidius rhopalosiphi: a consequence of aphid defensive behaviour. Ecological Entomology, 9, 149-155.

Gardner, S.M & Dixon, A.F.G. (1985) Plant structure and foraging success of Aphidius rhopalosiphi (Hymenoptera: Aphidiidae).  Ecological Entomology, 10, 171-179.

Gaston, K.J., Gauld, I.D. & Hanson, P. (1996) The size and composition of the hymenopteran fauna of Costa Rica.  Journal of Biogeography, 23, 105-113.

Griffiths, D.C. (1960) The behaviour and specificity of Monoctonus paldum Marshall (Hym., Braconidae), a parasite of Nasonovia ribis-nigbi (Mosley) on lettuce. Bulletin of Entomological Research, 51, 303-319.

Hardie, J., Nottingham, S.F., Powell, W. & Wadhams, L.J. (1991) Synthetic aphid sex pheromone lures female parasitoids.  Entomologia experimentalis et applciata, 61, 97-99.

Harrington, R. (1994) Aphid layer. Antenna18, 50-51.

Hopkins, A.D. (1917) Contribution to discussion.  Journal of Economic Entomology, 10, 92-93.

Holler, C. (1991) Evidence for the existence of a species closely related to the cereal aphid parasitoid Aphidius rhopalosiphi De Stefani-Perez based on host ranges, morphological characters, isoelectric focusing banding patterns, cross-breeding experiments and sex pheromone specificities (Hymenoptera, Braconidae, Aphidiinae. Systematic Entomology, 16, 15-28.

http://www.biologicalcontrol.info/aphid-primary-and-hyperparasitoids.html

Laing, J. (1937) Host-finding byinsect parasites 1. Observations on the finding of hosts by Alysia manducator, Mormoniella vitripennis and Trichogramma evanescensJournal of Animal Ecology, 6, 298-317.

Mackauer, M. (1965) Parasitological data as an aid in aphid classification. Canadian Entomologist, 97, 1016-1024.

McNeil, J.N. & Brodeur, J. (1995) Pheromone-mediated mating in the aphid parasitoid, Aphidius nigripesJournal of Chemical Ecology, 21, 959-972.

Monteith, L.G. (1955) Host preferences of Drino bohemica Mesn. (Diptera; Tachnidae) with particular reference to olfactory responses.  Canadian Entomologist, 87, 509-530.

Oliver, T.H., Timms, J.E.L., Taylor, A. & Leather, S.R. (2006) Oviposition responses to patch quality in the larch ladybird Aphidecta obliterata (Coleoptera: Coccinellidae): effects of aphid density, and con- and heterospecific tracks. Bulletin of Entomological Research, 96, 25-34.

Outreman, Y., Le Ralec, A., Plantegenest, M., Chaubet, B, & Pierre, J.S. (2001) Superparasitism limitation in an aphid parasitoid: cornicle secretion avoidance and host discrimination ability. Journal of Insect Physiology, 47, 339-348.

Powell, W. & Zhi-Li, Z. (1983) The reactions of two cereal aphid parasitoids, Aphidius uzbekistanicus and A. ervi to host aphids and their food-plants.  Physiological Entomology, 8, 439-443.

Reuter, O.M. (1913). Lebensgewohnheiten und Instinkte der Insekten (Berlin: Friendlander).

Stary, P. & Rejmanek, M. (1981) Number of parasitoids per host in different systematic groups of aphids: The implications for introduction strategy in biological control (Homoptera: Aphidoidea; Hymenoptera: Aphidiidae). Entomologica Scandinavica, Suppl. 15, 341-351.

Riley, W.A. (1931) Erasmus Darwin and the biologic* control of insects. Science, 73, 475-476.

Sheehan, W. & Shelton, A.M. (1989) The role of experience in plant foraging by the aphid parasitoid Diaeretiella rapae (Hymenoptera: Aphidiidae).  Journal of Insect Behavior, 2, 743-759.

Symondson, W.O.C., Sunderland, K.D., & Greenstone, M.H. (2002) Can generalist predators be effective bicontrol agents? Annual Review of Entomology, 47, 561-594.

Thompson, W.R. (1930) The principles of biological control. Annals of Applied Biology, 17, 306-338.

Thorpe, W.H. & Caudle, H.B. (1938) A study of the olfactory responses of insect parasites to the food plant of their host.  Parasitology, 30, 523-528.

Van Emden, H.F., Spongal, B., Wagner, E., Baker, T., Ganguly, S. & Douloumpaka, S. (1996) Hopkins’ ‘host selection principle’, another nail in its coffin.  Physiological Entomology, 21, 325-328.

Van Lenteren, J.C. (2012) The state of commercial augmentative biological control: plenty of natural enemies, but a frustrating lack of uptake. BioControl, 57, 1-20.

Van Lenteren, J.C. & Woets, J. (1988) Biological and integrated control in greenhouses.  Annual Review of Entomology, 33, 239-269.

Vinson, S.B. (1976) Host selection by insect parasitoids.  Annual Review of Entomology, 21, 109-133.

Wheeler, W.M. (1922). Social life among the insects: Lecture II. Wasps solitary and social. Scientific Monthly, 15, 68-88.

Wheeler, W.M. (1928) Foibles of Insects and Men.  Alfred Knopf, New York

Wickremasinghe, M.G.V. & Van Emden, H.F. (1992) Reactions of adult female parasitoids, particularly Aphidius rhopalosiphi, to volatile chemical cues from the host plants of their aphid prey. Physiological Entomology, 17, 207-304.

*This is how he spelt it; not a mistake on my part J

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Pick and mix 17 – gleanings from the web

A new approach to weed control?

A very personal and accessible paper about a rare butterfly by Nick Haddad

Why conserving species is important – warning for entomologists, there are a lot of vertebrate pictures 🙂

We need to conserve entomologists too

How some German cities are encouraging organic food gardens

George Monbiot admits that he was wrong to advocate global veganism; a great read but note that he has since qualified his view somewhat

And here is an article about George Monbiot’s controversial views about rewilding nature reserves and National Parks

Moving account of the life of the last Carolina parakeet that went extinct a century ago

A fun post from Kelly Jowett about filming a beetle larva

An interesting article about the harm done to Paris by modern architecture – Personally I think London has suffered more than Paris

 

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Inspiring the next generation of entomologists?

In the last couple of weeks, I have had the privilege to be involved in two different types of outreach involving the younger generation.  The first was Skypeascientist, which I came across via a blog post by Amy Parachnowitsch on Small Pond Science. Amy was so enthusiastic about it that I couldn’t resist signing up, to what is a great idea; in their own words “Skype a Scientist matches scientists with classrooms around the world! Scientists will skype into the classroom for 30-60 minute Q and A sessions that can cover the scientist’s expertise or what it’s like to be a scientist. We want to give students the opportunity to get to know a “real scientist”, and this program allows us to reach students from all over the world without having to leave the lab!” My first, and so far only, but hopefully not my last match was with a small primary school in the Cumbrian fells.  We had a bit of trouble with getting Skype working to begin with, but once contact was established I was subjected to some great, and in a couple of instances, tough questioning; what are the mots abundant insects in the world for one.  We covered what I did, why I did it and how I got started, as well as questions like the what is the most dangerous insects in the world, had I found any new insects, where had I been to study insects,  and from one little joker “have you ever had ants in your pants?”.  All in all, a very positive and enjoyable session and one, that I hope will result in at least one future entomologist, although sadly, by the time he or she arrives on our soon to start new entomology undergraduate degree, I will be long retired

The second outreach event was the Big Bang Fair held in Birmingham.  I participated in this last year and having enjoyed it so much, volunteered to help on two of the days; the fact that one of the days coincided with a deadly boring committee meeting that I would have had to attend otherwise, was purely coincidental 😉 If you’ve never heard of it, the Big Bang UK Young Scientists and Engineers Fair is the UK’s largest celebration of science, technology, engineering and maths, for young people, and is the largest youth event in the UK. The fair takes place annually in March, and was first run in 2009.  We, the Royal Entomological Society and Harper Adams University, first attended it last year, when a former student of mine, Fran Sconce, now Deputy Director of Outreach at the Royal Entomological Society, convinced us that it was a great event with which to become involved and to showcase our favourite science, entomology.  Fran was in charge this year too and did a sterling job as did the many volunteer demonstrators, drawn from among our current MSc entomologists and former students now doing PhDs.  They all did a fantastic job and I was hugely impressed by them all.

This was one of those events where the pictures tell the story but there were a few things that struck me.  First, I was surprised at how many of the teenage boys were afraid and disgusted by the thought of touching insects, the girls on the other hand, in the main were easier to win over to the concept.  When I was a teenager, now many years ago, it was the other way around.  Too much time spent indoors playing ‘shoot them up’ games perhaps might explain this, but perhaps that is too simple a view? Conversely pre-teens of both sexes seemed to respond in the same way, and overall were much easier to convince that it was safe and enjoyable to hold an insect.  Sadly, this seems to point to some anti-insect (maybe even Nature) ‘conditioning’ happening in young people once they leave primary education. Second, I was very surprised by how many times I was asked if the insect would bite them and/or was dangerous.  As I pointed out many times, “Would I be holding them and offering to let you hold them if they did and were?”  That said, I was very pleased that out exhibit attracted so much positive attention.  Some children made a lot of return visits 😊

 Now over to the pictures, which show the diversity of the young and older folk who were entertained and enthralled by our hard-working insects and volunteers.

 

One of the current MSc Entomology students and also a Royal Entomological Society Scholar, Brinna Barlow, demonstrating that you don’t have to be old, bearded and male to be an entomologist.

The First Day Team – the old and the new

A hive of activity at the entomology exhibit

 

Swarms of future entomologists?

Visitors and volunteers buzzing with enthusiasm

Some of our volunteers, Entomology MSc students past and present

 

Our new Entomology lecturer, Heather Campbell, showing that although she is an ant specialist, leaf insects are also cool.

Yours truly demonstrating that quite a few entomologists are oldish, greyish, bearded and male, but remember, we were young once 🙂

Bearded and male, but definitely younger

And finally, without the enthusiasm, dedication, and hard work of Fran Sconce, and the willingness of our current MSc Entomologists to give up some of their exam revision time, our exhibit would have been much diminished.  It was a privilege to stand alongside them all.

The Director and star of the show, Fran Sconce, with one of her co-stars, both fantastic ambassadors for entomology.

 

Post script

This post has the dubious distinction of being the first one I have ever posted while at sea; the Dublin to Holyhead ferry, m.v. Ulysses to be precise 😊

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A Swarm of Happy Verrallers – The Verrall Super 2018

Twice a year I swap my battered, but very comfortable Desert Boots, for my slightly less battered and much more uncomfortable

My Desert Boots looking even more battered than normal as they suffered somewhat during the recent visitation from the “Beast from the East”.

shiny black shoes; once for our annual graduation ceremony and secondly for the annual Verrall Supper.  I have written about the Verrall Supper more than once and for those of you foolish enough to want to my previous accounts please click this link.  This year the Verrall Supper was held on March 7th at our now customary venue, The Rembrandt Hotel in South Kensington. There were 176 Verrallers this year, of which 32% were female, a very slight increase on last year; I still hope one day to achieve a 50:50 split. And I think that as there are a significant and growing number of younger female entomologists, that this is not a vain ambition.  Clive Farrell of the Entomological Club was the Master of Ceremonies, although he did have an alarming tendency to call me to the microphone when I was least expecting it.  Chris Lyal, in the absence of the Reverend Dr David Agassiz, and being the most Christian member of the Club, said the Grace and launched us into what was, for both meat eaters and vegetarians, an extremely well cooked and presented meal.

We welcomed several overseas members, Tom and Soo-Ok Miller from the USA, Stephen Clement (USA), Rufus Isaacs also from the USA (Michigan State), but an old friend from my Silwood Park days, Wan Jusoh from the National University of Singapore and a group of Italian forensic entomologists, Giorgio Giordani, Jennifer Pradelli,  Fabiola Tuccia and Stefano Vanin,  currently based at the University of Huddersfield.

I had two cameras with me, a new one which I have not quite got the hang of, and, as a spare, my old one, in case the new one got the better of me.  My camera work is never particularly good and at events where alcohol flows in profuse quantities, it does tend to get worse as the evening progresses 😊  That seems an appropriate juncture at which to drag out the old adage “A picture paints a thousand words” and let the cameras do the talking.

The Calm before the storm. Clive Farrrell and me getting ready for the swarm.

We were trying to be more organised this year and set up two registration desks in an attempt to cut down queuing time, but it turned out that excited, and possibly already slightly tipsy entomologists, are not very good at reading signs.

Clive Huggins, an unidentified back, Mike Hassell, Mike Singer and Camille Parmesan

Jim Hardie’s back, Richard Lane’s profile, Patricia Ash(?), Mary Cameron, Luke Tilley and Kirsty Whiteford’s back.

Wan Jusoh, Stephen Clement, Richard Harrington, Stuart Reynolds

Rufus Isaacs and Jim Hardie

 

A selection of entomological bling and accessories

Entomological posturing – names withheld to save embarrassment 😊

Former and present students of mine, Jasper Hubert, Fran Sconce and James Fage

The Verrall Secretary before the wine took effect with Tilly Collins and Jasper Hubert

Anna Platoni, Maya Leonard (M G Leonard, author of the Beetle Boy trilogy), Matthews Esh and Craig Perl

Two former students doing their annual pose – Ashleigh Whiffin and Craig Perl

The Happy Throng, Max Barclay in the foreground.

Linda Birkin, Soo-Ok and Tom Miller centre back and Stuart Reynolds.

The RHS Entomologists, Stephanie Bird, Anna Platoni, Andy Salisbury and Hayley Jones – photo ‘borrowed’ from a tweet by Andy Salisbury

Ashleigh Whiffin, Maya Leonard, Sally-Ann Spence and Zoe Simmons – photo ‘borrowed’ from Sally-Ann Spence’s Twitter account

Former Harper Adams University MSc Entomology students – Scott Dwyer, Christina Faulder, Liam Crowley, Ben Clunie and Ruth Carter – photo ‘borrowed’ from Scott Dwyer’s Twitter feed.

The new camera adding a special effect?

Not for the faint-hearted – there are some insects there!

Someone asked me what one called a group of entomologists, I answered swarm, hence the title of this post.  Someone else, Tilly Collins I think, suggested melee and another suggested that by the end of the evening the swarm was better termed an inebriation 😊

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When did I become it? The fall and rise of passive and active voices in science writing

 

A few weeks ago, one of Stephen Heard’s excellent blog posts reminded me about the passive versus active voice debate.  I was once a passionate opponent of the active voice and the use of the first person singular and plural (Leather, 1986)*. In fact, during my tenure as Editor-in-Chief of Ecological Entomology (1996-2003) my Editorial Assistant/Copy Editor took great pleasure in converting, the mainly USA-authored actively written papers to passive conformity 😊 People often mention that they were ‘trained’ to write in the third person as this was regarded as being more scientific and less likely to lead to biased interpretations of data. In my 1986 paper I adopted a similar view and added that using the first-person singular could lead to a sense of ‘ownership’ and a subsequent reluctance to accept criticism.  But that was then, this is now, and those of you who read my scientific papers as opposed to my blog, will see that the first person singular and plural are to be found there.

Stephen says in his blog “Most of us were trained to write science in the passive voice, and most of us are accustomed to reading science in the passive voice.” In an idle procrastinating moment, I wondered when the impersonal passive way of writing became standard.  As an Editor of a couple of society journals (Annals of Applied Biology and Insect Conservation & Diversity) I have free access to the back numbers of the journals of the Association of Applied Biologists and the Royal Entomological Society to the year dot.  I decided to do a rather limited, and I hasten to add, not very replicated study, on the rise and fall and return of the active voice in two journals, Annals of Applied Biology and Ecological Entomology (formerly Transactions of the Royal Entomological Society).

As an aphidologist I felt compelled to start with a quote from one of our most distinguished alumni, the great Thomas Henry Huxley.  Just to complicate things, it is also in neither of the two journals I surveyed 😊. Huxley (1858) not only uses I profusely, but also cites and quotes chunks of papers written 50 years earlier which also use I.  It seems that Victorian entomologists and their predecessors had no problems with ‘owning’ their opinions and observations.

If we jump forward sixty years or so to the first issue of Annals of Applied Biology (1914) we see, even though the writing is not exactly thrilling, that it is active, and the authors, as demonstrated by the following example, had no problems with using the personal pronoun.

“This seemed to the present author to be a very important question about the two life-cycles described for Aphis rumicis. It intimated that the two parallel life-cycles might be merged into one by crossing from Euonymus to Broad Bean and from Rumex to Poppies. If the two life-cycles proved to be absolutely constant and separate, a very important feature would be established, namely the establishment of two biological species (A. euonymi and A. rumicis), both resembling each other in structure but differing physiologically in habitat. As the results obtained in these experiments will show, Aphis euonymi will heavily infest Broad Beans, and Aphis euonymi reared on Rumex will heavily infest both Broad Bean and Poppies.  Thus the two life- cycles may be merged into one.  The life-history, however, has not been completed, as owing to leaving England in September, I have been unable to trace the history of the sexuparae.”  (Davidson, 1914).

We also find a very similar style in articles published by the Royal Entomological Society in the same year (e.g. Lamborn et al., 1914).

I wondered if the traumatic experience of the First World War would have affected scientific writing styles, but found, at least in my two sample journals, that during the 1920s nothing much changed in the style in which papers were written.  In Annals of Applied Biology, the change from personal pronouns and active voices begins in the early 1930s, 1933 being the last year in which the majority of papers still used the more personal style, but the following examples show, the tide was turning.

“So far as we are aware, no systematic investigation of the carbohydrates of crinkle infected plants has been made heretofore, and the present work was initiated and carried out on the same lines as was employed by us for leaf-roll. It should also be mentioned that our colleague, Mr George Cockerham, has carried out a similar investigation on mild mosaic at the substation” (Barton-Wright & McBain (1933).

“In 1930 we grease-banded sixty plum trees before the sawflies had emerged and on these we caught seventeen adults.  Later on it was noticed that these trees were badly infested with sawfly larvae.  From this it would appear that most of the sawflies must have flown on to the trees, either directly from the ground or from neighbouring trees. In order to study their habits, adults were collected in the orchard and kept on plum shoots in cages” (Petherbridge et al., 1933).

The early to mid-1930s marks an emerging trend toward the third person appearing, for example; “This paper describes our work on this disease during 1932. We consider that we have collected sufficient evidence to show conclusively that the disease is caused by the feeding of the tea mosquito bug (Helopeltis bergrothi Reut.) on the more mature green stems of tea.  We consider that fungi play a purely secondary part in the etiology of the disease. We suggest the name ((gnarled stem canker” as being a more descriptive name for the disease than ((stem canker” or “branch canker,” which may include many different diseases” (Leach & Smeed, 1933). The rest of this paper is, however, strongly third person impersonal.

Jackson (1933) writing about the tstetse fly refers to himself as The Author and has a very dry and impersonal third person reporting style throughout. In a similar style, here is Maldwyn Davies**, “The writer has been concerned solely with entomological studies and the relation that the work has to the seed potato and virus problems” (Maldwyn Davies, 1934).

This, the last pre-war use of the first person in the Annals, is, coincidentally, in the form of a tribute to the aforementioned Maldwyn Davies; “Dr W Maldwyn Davies died in February 1937 after preparing the first draft of this report; and it has therefore fallen to me, as one very closely associated with him in his ecological work on aphides, to prepare the Report for publication. I have endeavoured simply to make the necessary verbal corrections which, I feel confident, Dr Davies himself would have desired” (Maldwyn Davies & Whitehead, 1939).

Post-war the third person and passive voice is firmly established (e.g. Prentice & Harris, 1946) and in this paper I was pleased to see the authors capitalizing Petri as in dish and comparing with not to, two errors commonly evident in modern papers 🙂

Over at the Royal Entomological Society and in their flagship journal, Transactions, things are very different.  Here in 1949, some 15 years after the last mention of the personal pronoun in the Annals, we find a retired Lieutenant Colonel from the Indian Medical Service writing very actively indeed:

“It was not until 1877 that Selys gave the first definition of the genus Agriocnemis, listing under it ten species, including in this number exilis, but excluding solitaria and rufipes ; the former was placed in a new genus, Argiocnemis, the latter relegated again to its former genus, Agrion! It is diacult to fathom the Selysian reasons for this volte face, for he had the type of rufipes before him in his own collection: nor can he be said to have forgotten his original reference, for he actually cites Pollen and Van Dam where rufipes is listed under Agriocnemis“ (Fraser, 1949).

I then jumped forward in time to 1955, an excellent year, the year a new entomologist was hatched; I was born 🙂  In the Annals I found only one paper with a first person mention and that was in the acknowledgements (Shaw, 1955).   In Transactions however, there is a mixture, for example Tottenham (1955), a Vicar, using the active first person singular and Downes (1955) a government taxonomist using the third person passive.  There are however, indications that the third person passive style is growing in popularity, and by 1962 you can read passages like this “It was desirable to obtain data on the dispersal of adults to supplement results obtained in the weekly samples” (Anderson, 1962).  This was done at my old stamping ground, Silwood Park and marks the increasing number of professional entomologists beginning to publish in the Transactions.  By 1965, the year we left Jamaica, there is only one instance of active, first person plural reporting, in the persons of Trevor Lewis and Roy Taylor, two legendary entomologists from Rothamsted, the former still alive and relatively well (Lewis & Taylor, 1965).  They were, however, not the last to follow this practice. In 1975, the final year of Transactions (metamorphosed to Ecological Entomology in 1976, both forms are still in use. In the Annals on the other hand, the papers in the issues of 1965 and 1975 are both firmly passive and impersonal.

So why the difference between the two journals?  It has nothing do with being an entomologist per se.  Rather I think, it is to do with the difference in fields of study.  Annals of Applied Biology is, and was, run by the Association of Applied Biologists, so from the very beginning, it was the mouthpiece of professional biologists working in agriculture and forestry, who were mainly employed at Government Research Institutes or Universities.  The Transactions of the Royal Entomological Society of London, on the other hand, had a much longer history, and was, for almost the first century of its existence, dominated by the output of Fellows of the Royal Entomological Society, most of whom were, what we would now call amateur entomologists.

My hypothesis, admittedly based on very limited data, is that as “professional scientists” applied biologists were more likely to perceive writing in an impersonal passive manner as more appropriate to their standing as paid scientists, whereas the parsons, medical practitioners, military officers, gentlemen and other amateur naturalists writing on entomological matters, felt no such compulsion.  That does not however, explain why my Editorial Assistant for Ecological Entomology, had a constant battle against the use of the active and personal voice by authors from the USA; one of the first countries to have a professional entomological extension service J  Perhaps one of my North American readers can suggest an answer?

Although I am still sparing in my use of the personal pronoun and the active voice in my formal scientific writing, I am no longer averse to taking ownership of my work.  Regular readers of my blog will know that I have fully embraced the practice in my less formal offerings and revel in the freedom to express my personal viewpoints with vim and vigour, although of course all firmly backed up with documented evidence 🙂

References

Anderson, N.H. (1962) Bionomics of six species of Anthocoris (Heteroptera : Anthocoridae) in England. Transactions of the Royal Entomological Society of London, 114, 67-95.

Barton-Wright, E. & McBain , A. (1933) Studies in the  physiology of the virus diseases of the potato. II. A comparison of the carbohydrate metabolism of normal with that of crinkle potatoes; together with some observations on carbohydrate metabolism in a “carrier” variety. Annals of Applied Biology, 20, 525-548.

Brierley, W.B. (1934) Some viewpoints of an applied biologist. Annals of Applied Biology, 21, 351-378.

Davidson, J. (1914) The host plants and habits of Aphis rumicis Linn., with some observations  on  the  migration of, and infestation of, plants  by  aphides.  Annals of Applied Biology, 1, 118-142.

Doncaster, J.P. & Kassanis, B.  (1946) The shallot aphis, Myzus ascalonicus Doncaster, and its behaviour as a vector of plant viruses   Annals of Applied Biology, 33, 66-68.

Downes, J.A. (1955) Observations on the swarming flight and mating of Culicoides (Diptera: Ceratopogonidae. Transactions of the Royal Entomological Society of London, 106, 213-236.

Fraser , F.C. (1949) The Zygoptera of Mauritius (Order Odonata). Transactions of the Royal Entomological Society of London, 100, 135-146.

Huxley, T.H. (1858) On the Agamic Reproduction and Morphology of Aphis.–Part I. Transactions of the Linnean Society London, 22, 193-219. 

Jackson, C.H.N. (1933) On an advance of tsetse fly in Central Tanganyika. Transactions of the Royal Entomological Society, 81, 205-222.

Lamborn, A., Bethune-Baker, G.T., Distant, W.L., Eltringham, H., Poulton, E.B., Durrant, J.H. & Newstead, R. (1914) XX. On the relationship between certain West African insects, especially ants, Lycaenidae and Homoptera. Transactions of the Royal Entomological Society of London, 61, 436-498.

Leach, K. & Smeed, C. (1933) Gnarled stem canker of tea caused by the capsid bug (Helopeltis bergrothi Reut.). Annals of Applied Biology, 20, 691-706.

Leather, S.R. (1996) The case for the passive voice.  Nature 381, 467.

Lewis, T. & Taylor, L.R. (1965) Diurnal periodicity of flight by insects.  Transactions of the Royal Entomological Society of London, 116, 393-43.

Maldwyn Davies W. (1934) Studies on aphides infesting the potato crop: ii. aphis survey: its bearing upon the selection of districts for seed potato production. Annals of Applied Biology, 21, 283-299.

Maldwyn Davies, W & Whitehead, T. (1939) Studies on aphides infesting the potato crop: vii. Report on a survey of the aphis population of potatoes in selected districts of Scotland (25 july-6 august 1936). Annals of Applied Biology, 26, 116-134.

Petherbridge, F.R., Thomas, I. & Hey, G.L. (1933) On the biology of the plum sawfly, Hoplogampa flava L.†, with notes on control experiments. Annals of Applied Biology, 20, 429-438.

Prentice, I.W. & Harris, R.V. (1946) Resolution of strawberry virus complexes by means of the aphis vector Capitophorus fragariae Theob.  Annals of Applied Biology, 33, 50-53.

Shaw, M.W. (1955) Preliminary studies on potato aphids in north and north-east Scotland   Annals of Applied Biology, 43, 37-50.

Tottenham, C.E. (1955) Studies in the genus Philonthus Stephens (Coleoptera: Staphylinidae. Transactions of the Royal Entomological Society, 106, 153-195.

 

Post script

The following couple of sentences must surely be a contender for the prize of most impersonal writing “The first to apply the theory of of parallel evolution to entomophagous parasites was Mackauer (1961, 1962b).  He found that the host range of members of the…”  Why you are now asking is this such a great example of impersonal writing?  All becomes clear when I reveal that the author of these sentences is writing about himself (Mackauer, 1965).

Mackauer, M. (1965) Parasitological data as an aid in aphid classification.  Canadian Entomologist, 97, 1016-1024.

 

*This paper, my only appearance in Nature, received a lot of negative published responses, but a lot of personal emailed positive ones.  Even with my thick skin I felt a little bruised by the experience 😊

**The entomologist, not the tenor

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My group is bigger, better and more beautiful than yours – The annual MSc Entomology trip to the Natural History Museum, London, 2018

This week we went on one of my favourite trips with the MSc Entomology students.  We visited the Natural History Museum in London.  We got off to fantastic start – all the students, and staff, arrived at the arranged time of 0645, something that had never happened before :-). The weather was fine, although at that time in the morning it was too dark to really appreciate it, and off we set.  I should have known that something would go wrong and sure enough the traffic was awful, and we had to make an unscheduled stop at a motorway service station to make sure our driver didn’t exceed his quota of working hours.

The now much delayed coach basking in the sunshine at a motorway service station.

Some of the MSc students; remaining cheerful despite the delay.

Forty-five minutes later we set off again and despite encountering a few further delays arrived safely, albeit almost an hour and a half late.  Luckily our host for the day Erica McAlister (@flygirlNHM) was ready and waiting and very efficiently got our visit back on track.  This year we were shown Colossal Coleoptera by Michael Geiser, Huge Hymenoptera by Nathalie Dale-Skey, Lustrous Lepidoptera by Alessandro Giusi and Deadly Diptera by Erica McAlister.   All our specialist hosts were, as you would expect, very keen to extol the virtues of their groups, and who can blame them.  I do the same with Awesome aphids 🙂 We are always very appreciative of the time and care that the NHM entomologists give us, especially as they have, sadly, recently had their numbers reduced.  Hopefully, as the realities of the problems associated with insect conservation and identification become even more apparent than they already are, we will see the appointment of more entomologists to this very much-needed global resource.  Here are some pictures to give you a flavour of the day.

Mouse mat for forensic entomologists 🙂

Alessandro Giusti waxing lyrical about the biggest, the smallest and the most beautiful Lepidoptera (moths as far as he is concerned).

 

The large and the small (a really bad photo by yours truly, I am still getting to grips with my new camera)

Natalie Dale-Skey extolling the virtues of Hymenoptera

They don’t have to be big and tropical to be beautiful – these are tiny but gorgeous

I do like a good wasp nest 🙂

Erica McAlister on the sex life of flies

The biggest flies in the world pretending to be wasps

A selection of flies

I was very impressed that the Crane fly still has all its legs attached.  I collected Crane flies for my undergraduate collection and had to resort to sticking their legs on to a piece of card.

Not quite the rarest fly in the World but as its larvae live inside rhinoceroses it could be in trouble 😦

Big beautiful beetles

Cockchafers aren’t really this big, but wouldn’t it be awesome if they were?

MSc Entomology (@Entomasters) at the end of the visit.  Photo courtesy of Heather Campbell (@ScienceHeather), our newest member of staff

Once again, a huge vote of thanks to Erica and colleagues for making this a memorable visit.  We had a fantastic day.

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Pick and mix 16 – more links to check out

Wise words from the Oxford University Museum of Natural History

If you live in the UK and like trees in your garden, here are some suggestions of native species to plant – all are good for insects and birds

On managing your urban garden as a productive ecosystem

An excellent resource of historical research done at Rothamsted Research Station – this section all about bees

Still more on bees, this time how bees that are feeling unwell change their diets to fight of infection

More and more species being discovered yet taxonomists are an endangered species themselves; they deserve our respect and more funding

They may be unwanted neighbours but these are beautiful pictures from Gil Wizen

Maria Sibylla Merian, a prodigy from the 17th Century; artist, naturalist and entomologist – remarkable achievements

Many animals, including insects, can count

If you have ever wondered why entomologist kill insects and have 28 minutes to spare listen to this

An irreverent obituary of legendary French chef Paul Bocuse

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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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Battle of the Beetles – Kunoichi Beetle Girl – Maya Leonard Does it Again!

Battle of the Beetles, M.G. Leonard, 2018, Paperback, ISBN 9781910002780, Chicken House Publishing Ltd., Frome, UK.

I’m sad, I’m satisfied, I’m very impressed, I’m in a dilemma.  I’ve just finished reading Battle of the Beetles, the final instalment of M.G. Leonard’s Beetle Boy trilogy, which means, very sadly, that the adventure is over ☹

I’m satisfied, nay, very satisfied, because this final volume has lived up to the expectations raised by the previous two in the series, Beetle Boy and Beetle Queen.  I’m very impressed because Battle of the Beetles is so much more than an adventure story.  As well as being thrilling, heart-stopping, and full of action, it is also educational and raises some very important and thought-provoking issues.  I’m in a dilemma, because how can I review this excellent book without giving away spoilers?

First, just to reiterate this is a great book. It is a literary roller-coaster, featuring jungle escapades, martial arts, near-death experiences, family reunions, coleopteran gymnastics, terrifying events, pathos, bathos, scatological humour and a happy ending. In summary, a fantastic couple of hours entertainment.  If you have read the first two books in the series, you won’t be disappointed; buy or get someone to buy Battle of the Beetles for you as soon as possible.  If you haven’t read the earlier books you have some catching up to do 😊

The underlying theme of this instalment is metamorphosis and physiology and be warned there is some very memorable and slightly disturbing imagery connected with these themes.  You will never see Silphids (carrion beetles) in the same way again. Speaking of imagery, the illustrations by Karl James Mountford are stunning.  While amusing and entertaining there are some very serious underlying concepts that hopefully will not be overlooked by readers.  We learn about environmentally friendly means of pest control, e.g. pheromone disruption and the very successful and relevant real-life Sterile Insect Techniques (SIT). SIT was pioneered as a control technique against the screw worm, a serious pest of cattle in the USA (Baumhover et al., 1955; Knipling, 1955) and is now seen as a practical way forward for mosquito control or eradication (Benelli, 2015).  This may however, be the first time it has been mentioned in a work of fiction for children. Another first for Maya Leonard 🙂 The lack of undergraduate entomological training in the UK also gets a mention; the good news is that the MSc in Entomology at Harper Adams University is shortly to be joined by a new undergraduate degree, Zoology with Entomology 😊

The most thought-provoking theme is, however, that of rewilding, much in the news these days.  How far would you be willing to go to conserve species and protect the environment?  At one stage I almost felt sympathetic towards Lucretia Cutter; a truly brilliant twist to the story.  I don’t think I can say much more without giving too much away.

Embrace your inner beetle, throw away your prejudices and enjoy this fantastic adventure.  An enthralling read for everyone aged nine and above, including entomologists and ecologists.

References

Baumhover, A.H., Graham, A.J., Bitter, B.A., Hopkins, D.E., New, W.D., Dudley, F.H. & Bushland, R.C. (1955) Screw-worm control through release of sterilized flies.  Journal of Economic Entomology, 48, 462-466.

Benelli, G. (2015) Research in mosquito control: current challenges for a brighter future. Parasitology Research, 114, 2801-2805.

Knipling, E.F. (1955) Possibilities of insect control or eradication through the use of sexually sterile males. Journal of Economic Entomology, 48, 459-462.

 

Post script

I must also compliment Maya and her copy editor.  This is one of the most typo-free books I have read for some time.  I only found one error/typo, bearing used instead of baring.  Excellent proof reading.

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Pick and mix 15 – some results from sampling the World Wide Web

Prospects for UK agriculture post-Brexit look grim

It wasn’t just green plants that helped oxygenate the Earth

Will meat no longer be on the menu by 2100? A speech from the Oxford Farming Conference

A fairer food supply system?

An interesting account of agroecology in two different continents

Climate and weather are not the same thing – Donald Trump and his ilk need to realise this

What Chernobyl did to insects – an artistic exploration

Some amazing natural history art from almost 300 years ago

Ray Cannon on a big black beautiful bumblebee

Ecological guilt trips, me I gave up flying almost twenty years ago

 

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Filed under Pick and mix