Unsolved mysteries or unasked questions? The mysterious case of the bumbling bibionids

Some years ago, Ole Heie published a paper discussing what he called aphid mysteries not yet solved (Heie, 2009).  These included such gems as the shark’s fin on the giant willow aphid and why are aphids so fussy about their host plants? I could add a few of my own; of the three very common aphids that feed on sycamore, one, Periphyllus testudinaceus, is commonly attended  by ants another P. acericola, is sometimes attended by ants and the third, Drepanosiphum platanoidis is attacked by ants. The question that one would ask is why this gradation when all three aphids live on the same tree and all produce lots of honeydew, the ant’s reward. People have pointed out that those ants that are obligately ant-attended have evolved a specific structure, the trophiobiotic organ (Heie, 1980) and that the siphunculi in non-ant attended aphids are longer than those of ant-attended species, which presumably enhances their defensive function (Way, 1963). These observations do not, however, answer the question as to why the association or lack of association arose, they just allow us to speculate about how the association has shaped the aphid, in essence an example of a circular argument.  Although I have raised the question, and you might respond and say that the question has been asked by voicing it, in my opinion, the question remains unasked (untested) and the mystery unsolved.  

There are plenty more aphid examples I could throw into the mix, but given the time of year when I started to write this, I thought I’d do a more topical unsolved mystery.  Why are St Mark’s flies (Bibio marci) so easy to catch? A simplistic answer is they are so easy to catch because they fly very slowly and appear to make no effort to avoid being caught.  I can literally grab them out of the air.  

One that I caught earlier -)

The real question is how come they are so easy to catch? Why, unlike the ubiquitous housefly, Musca domestica, which is nigh on impossible to sneak up on, (well by me at any rate, but perhaps you are better at it than me), has evolution produced such a dozy animal?  

Dipteran phylogeny (after Yeates et al., 2007). 

Bibionids appeared earlier in the evolution of flies than the Muscids and if you look at the phylogeny above you can see that as new Orders of flies arose, they moved from being long-legged, relatively clumsy fliers, such as the crane flies and Bibionids to the much more agile species we see in the Empids (dagger flies), Asilids (robber flies) and blue bottles and house flies.  Bibio marci is found across most of Europe while the housefly is found everywhere that humans are to be found, a truly global beast.  Based on distribution alone we could argue that M. domestica  is the more successful of the two. 

Their structure apart, are there any differences in their life history traits that might explain why natural selection has shaped adult Bibionids into being such easily caught organisms when compared with houseflies? Given the big differences in their flight agility we might expect their respective predators to be markedly different.  The eyes of a typical housefly have about 3400 ommatida (Sukontason et al., 2008) and process visual information around seven times more quickly than humans, enabling them to identify, and easily avoid attempts to catch or swat them, since they effectively see the human’s movements in slow motion. The eyes of bibionids on the other hand are divided into two halves, with one half pointing upwards, the other downwards.  The upward pointing half is used to locate mates while the downward pointing half is used for positioning (Zeil, 1983), so they are good at hovering (Ennos,1989), but not very agile in comparison with other flies, including, in my experience anyway, crane flies, which although looking clumsy are surpassingly good at not being caught*.  Despite these differences in flight ability, their predators are not very different.  Adult houseflies have many predators, including birds, reptiles, amphibians, various insects, and spiders which is pretty similar to St Mark’s flies, the adults of which form a substantial proportion of the diet of birds, such as starlings and chaffinches and are eaten by spiders and attacked by Empids (dagger flies) (D’Arcy-Burt & Blackshaw, 1991). 

What about their diets then? You might not realise it but we can describe adult houseflies as being mainly carnivorous; their primary food is animal matter, carrion, and faeces, but they also consume milk, sugary substances, and rotting fruit and vegetables. Although they don’t have jaws per se, they deal with solid foods by liquefying them with saliva before sucking it up.  Given their food preferences they are great at moving bacteria around the environment, hence their bad reputation as public health pests. Adult bibionids on the other hand are nectar feeders (Lewis & Smith, 1969; Smith & Lewis, 1972), so can be classified as beneficals due to their pollinating ability (Lewis & Smith 1969). As larvae, B. marci feed on leaf litter, both coniferous (von Schremer, 1958) and deciduous (Pobozsny, 1982), so again have a very important role in humification and soil formation (Pobozsny, 1982).  House fly larvae feed primarily on muck, dead and decaying material, animal faeces, pig manure being a particular favourite (Larrain & Salas, 2008; Pastor et al., 2011), which, like B. marci, makes them important components of the ecosystem. We are, however, concerned with the adults and their exposure to predators, and looking at their respective life styles it seems odd that B. marci is such a lethargic flyer as it would seem to be just as, or even more so, exposed to predators as the house fly.

That leaves us with the life cycle.  Is there something about B. marci’s life history traits that enables it shrug off the possibility of predation?  The adult has a short life cycle, one week, there is only one generation a year and the typical female lays 3330 eggs (Skartveit, 2002), so pretty prolific. The house fly has a longer adult life, and at 25oC lays just over 700 eggs (Fletcher et al, 1990), so although fecund, nowhere near as productive as B. marci.   They do however, whip through the generations, in temperate regions of the world getting through 10-12 generations in a year, so their multiplication rate is massive compared with that of our bumbling bibionid.

Given all the evidence, I would have thought that B. marci would benefit greatly by being a faster flyer and less conspicuous and/or unpalatable.  It is none of these things. It might be spatially aware, but its predator avoidance mechanisms seem to leave a lot to be desired and birds love to eat it. That said, it has been remarkably successful and was, in the past, regarded as an agricultural pest (Morris, 1921).  There does, however, seem to be growing evidence, that B. marci is not as numerous as it once was, (Grabener et al., 2020), so given the close association that the house fly has with humans and the current direction of global heating, I would bet that the former will, over the next few years decline in numbers and the latter become an even bigger pest. Sadly, this seems to be the direction we are heading with regard to insect numbers, those we love are threatened, those we hate are doing well ☹


 D’Arcy-Burt, S. & Blackshaw, R.P. (1991) Bibionids (Diptera: Bibionidae) in agricultural land: a review of damage, benefits, natural enemies and control. Annals of Applied Biology, 118, 695-708

Ennos, A.R. (1989) The kinematics and aerodynamics of the free flight of some Diptera. Journal of Experimental Biology,142, 49-85. 

Fletcher, M.G., Axtell, R.C., & Stinner, R.E. (1990) Longevity and fecundity of Musca domestica (Diptera: Muscidae) as a function of temperature. Journal of Medical Entomology, 27, 922–926.  

Grabener, S., Oldeland, J., Shortall, C.R. & Harrington, R. (2020) Changes in phenology and abundance of suction-trapped Diptera from a farmland site in the UK over four decadesEcological Entomology, 45, 1215-1219.

Healy K, McNally L, Ruxton GD, Cooper N, Jackson AL (2013). Metabolic rate and body size are linked with perception of temporal information. Animal Behaviour. 86, 685–696.  

Heie, O. (1980)  The Aphdioidea (Hemiptera) of Fennoscandia and Denmark. 1. Fauna Entomologica Scandinavica 9.Scandinavian Science Press, Klampenborg, Denmark. 

Heie, O.E. (2009) Aphid mysteries not yet solved (Hemiptera:Aphidomorpha). Monograph Aphids and Other Hemipterous Insects, 15, 31-48. 

Larrain, P.S. & Salas, C.F. (2008) House fly (Musca domestica L.) (Diptera: Muscidae) development in different types of manure. Chilean Journal of Agricultural Research, 68, 192-197.

Lewis, T. & Smith, B.D. (1969) The insect faunas of pear and apple orchards and the effect of windbreaks on their distribution. Annals of Applied Biology, 64, 11-20.

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

Skartveit, J. (2002) Variation in fecundity in relation to female size and altitude in Palaearctic Bibioninae (Diptera, Bibionidae). Studia Dipterologica9, 113-127

Smith, B.D. & Lewis, T. (1972) The effects of windbreaks on the blossom-visiting fauna of apple orchards and on yield. Annals of Applied Biology, 72, 229-238.

Sukontason, K.L., Chaiwong, T., Piangjai, S. et al. (2008) Ommatidia of blow fly, house fly, and flesh fly: implication of their vision efficiency. Parasitology Research, 103, 123–131

Pastor, B., Cickova, H., Kozanek, M., Martinez-Sanchez, A., Takac, P. & Rojo, S. (2011) Effect of the size of the pupae, adult diet, oviposition substrate and adult population density on egg production in Musca domestica (Diptera: Muscidae). European Journal of Entomology, 108, 587-596.

Pobozsny, M. (1982) The feeding biology of larval St Mark’s fly Bibio marci (Diptera: Bibionidae). Acta Zoologica Academie Scientiarum Hungariaicae, 28, 355-360.

von Schremer, F. (1958) Bibio larvae as utilisers of litter of dead needles. Anziger Schadlingskunde, 31, 151-153.

Way, M.J. (1963) Mutualism between ants and honeydew-producing Homoptera.  Annual Review of Entomology, 3, 307-344. 

Yeates, D.K., Wiegmann, B.M., Courtney, G.W., Meier, R., Lambkin, C., & Pape, T. (2007) Phylogeny and systematics of Diptera: Two decades of progress and prospects. Zootaxa1668, 565-590

Zeil, J. (1983) Sexual dimorphism in the visual system of flies: the compound eyes and neural superposition in bibionidae (Diptera). Journal of Comparative Physiology, 150, 379-393.  

*I speak from bitter experience; my second-year undergraduate insect collection was Tipulids, which turned out to be a lot more difficult to catch than I had anticipated.

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Green islands for the third and final time?

I have regaled you with tales of green islands twice before, first in relation to trees miraculously surviving mass defoliation events, and second, in terms of leaf miners and their exploitation of cytokinins.  This time it is the turn of the cowpat islets to make their appearance.  Those of you who are lucky enough to be able to walk in the countryside will probably have noticed that some of the fields you walk through are dotted with lots of clumps of longer grass and perhaps wondered what they are and why they are there.

A recently grazed pasture, showing very clear cowpat islets (Sutton, Staffordshire May 2021).

 If you look early enough or carefully later on, you will see that these clumps are associated with cowpats.  There have been a lot of theories about why these clumps arise, ranging from increased plant nutrition (Taylor & Rudman, 1966), after all we put manure on our gardens to improve plant growth, to unpalatability of the grass due to raised sugar levels (Plice, 1951).  This latter idea has since been dismissed, although the fact that cattle avoid feeding on these clumps has been well documented (Merten & Donker, 1964).  There is another explanation for why cattle avoid grazing near cowpats. You may not know it, but despite the fact that cattle don’t seem to have much control (or perhaps they just don’t care) over when and where they deposit their excreta, but cattle, despite the behaviour of bullocks, aren’t stupid. Just like you and me, they aren’t that keen on eating their own and other people’s sh*t.  A good reason for avoiding eating excreta, whether your own or someone else’s, is that areas contaminated with dung are associated with higher numbers of gastro-intestinal parasites (Boom & Sheath, 2008; Gethings et al., 2015), so it makes very good sense to avoid eating contaminated grass.  Whatever the reason, be it increased nutrition or distastefulness, the result is clumps of longer grass dotted around the pasture taking up between 20 and 30% of the field (Taylor & Rudman, 1966).

You may, by now, be wondering why an entomologist is going on about cowpats and grass clumps. Well, as you all know, in my world, everything comes round to entomology 🙂 It has been known for some time that hedges and hedgerows provide refuges for insects, admittedly, not all beneficial ones (Lewis, 1969; D’Hulster, M. & Desender, 1982), but nevertheless, an observation that led to the development of beetle banks and conservation headlands (Sotherton et al., 1989; Thomas et al., 1991). It is, however, not just field boundaries that can provide habitats for insects. Belgian coloepterist, the late Konjev Desender and colleagues, found that the sward islets provided extra overwintering sites for staphylinid beetles, which provide an important role in natural pest regulation (D’Hulster & Desender, 1984).  Strangely, well to me anyway, interest in the entomological role of sward islets died a death.  It wasn’t until almost thirty years later that a former colleague of mine, keen hemipterist Alvin Helden (now at Anglia Ruskin University), and colleagues, found that sward islets were also proving very important refugia for grassland Hemiptera and lycosid and linyphid spiders (Helden et al., 2010: Dittrich & Helden, 2012). Before the grazed sward recovered the islets, which in their study occupied 24% of the pasture, hosted about 50% of the total arthropod community.  So a very important role in conserving biodiversity within agroecosystems, but despite this very important finding, sward islet entomology has yet again fallen off the entomological radar 😦

Less recently grazed pasture, but cowpat islets still visible within the recovering sward (Sutton, Staffordshire, May 2021) but still, according to Alvin Helden, containing a higher density of arthropods than the surrounding grazed area (Helden et al., 2010).

I think that revisiting the ecology of sward islets would prove very rewarding for both MSc and PhD projects.  Off the top of my head I can come up with a couple of projects; for a PhD, given that the fertilisation level and type affected the relative abundance of two of the Hemipteran families, Delphacids and Cicadellids (Dittrich & Helden, 2012), a comparison of the fauna and flora of sward islets on conventional and organic farms would make a really rewarding project. Harking back to my interests in island biogeography a study of the size, floral composition, structure and distribution of sward islets and how this affects arthropod communities would make a neat MSc project or perhaps even another PhD.

I am sure that with a little bit of thought, many more projects, not just entomological could be devised. Over to you dear readers.


Boom, C.J. & Sheath G.W. (2008) Migration of gastrointestinal nematode larvae from cattle faecal pats onto grazable herbage. Veterinary Parasitology, 157, 260-266.

D’Hulster, M. & Desender, K. (1982) Ecological and faunal studies on Coleoptera in agricultural land III. Seasonal abundance and hibernation of Staphylinidae in the grassy edge of a pasture. Pedobiologia, 23, 403–414.

D’Hulster, M. & Desender, K. (1984) Ecological and faunal studies of Coleoptera in agricultural land IV. Hibernation of Staphylinidae in agro-ecosystems. Pedobiologia, 26, 65–73.

Dittrich , A.D.K. & Helden, A.J. (2012) Experimental sward islets: the effect of dung and fertilisation on Hemiptera and Araneae. Insect Conservation and Diversity, 5, 46–56.

Gethings, O.J., Sage, R.B. & Leather, S.R. (2015) Spatio-temporal factors influencing the occurrence of Syngamus trachea within release pens in the south West of England. Veterinary Parasitology, 207, 64-71.

Helden, A.J., Anderson, A., Sheridan, H. & Purvis, G. (2010) The role of grassland sward islets in the distribution of arthropods in cattle pastures. Insect Conservation and Diversity, 3, 291–301.

Lewis, T. (1969) The diversity of the insect fauna in a hedgerow and neighbouring fields. Journal of Applied Ecology, 6, 453-458.

Marten, G.C. &  Donker, J.D. (1964) Selective grazing induced by animal excreta. II. Investigation of a causal theory. Journal of Dairy Science, 47, 871-874.

Plice, M. J. (1951) Sugar versus the intuitive choice of foods by livestock. Agronomy Journal, 43, 341-342.

Sotherton, N.W., Boatman, N.D. & Rands, M.R.W. (1989) The ‘conservation headland’ experiment in cereal ecosystems. The Entomologist, 108, 135-143.

Taylor, J.C. & Rudman, J.E. (1966) The distribution of herbage at different heights in ‘grazed’ and ‘dung patch’ areas of a sward under two methods of grazing management. The Journal of Agricultural Science, 66, 29-39.

Thomas, M.B., Wratten, S.D. & Sotherton, N.W. (1991) Creation of ‘island’ habitats in farmland to manipulate populations of beneficial arthropods: Predator densities and emigration. Journal of Applied Ecology, 28, 906-917.

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Pick & Mix 61 – Terry Pratchett, chickens, trees, species conservation, wasps, bees, eating weeds and much more

Google’s new timelapse shows 37 years of climate change anywhere on earth, including your neighbourhood

Bay bees love carbs – By considering the nuances of bees’ dietary needs, we can design nutritionally balanced seed mixes that help pollinators shore up our ecosystems and food supplies.

Seirian Sumner writes about her love of wasps and why you and I should too

Why I only buy organic or truly free-range chicken and eggs – Revealed: true cost of Britain’s addiction to factory-farmed chicken – it comes at a price though. If you buy from a supermarket, a small mass reared chicken costs approximately £3, free-range’ same size, £9, and the same size organic, £18.

Jeremy Fox on which Terry Pratchett books to read and in which order – I don’t necessarily agree with him but always happy to spread the word about the late great Terry Pratchett. Fun fact, I once had his email address and used to correspond with him, Then one day, having just read the Carpet People and the Bromeliad trilogy and really enjoyed them I emailed him and said so, giving as my reason that it was like an updated and funny version of the Borrowers. Unfortunately he thought I was accusing him of plagiarism and that was the end of our relationship L

There aren’t enough trees in the world to offset society’s carbon emissions – and there never will be, but that doesn’t mean we should stop planting them

Mountain Avens – the Scottish sunflowers?

Sobering read from Charley Krebs – “There are times when we either act or give up, so if you think that the Covid epidemic, the conservation of endangered species, and the protection of old growth forests are irrelevant problems to your way of life, stop reading here. These three major problems are here and now and have come to a head as a crunch: do something or quit.”

Got a problem with Japanese Knotweed?  Try eating it 🙂

Terry McGlynn asks “Should reviewers of journal papers be paid?” 

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I Stand in Awe of Matthew Cobb – The Idea of the Brain

We should never dismiss past ideas – or people – as stupid. We will be the past one day, and our ideas will no doubt seem surprising and amusing to our descendants.”

All of the above and more

Having just finished writing a book for a general audience I know just how much work goes into it.  The number of papers, books and web sites that I had to read totally amazed me, and my book was only 35 000 words.  Matthew’s magnificent achievement, excluding notes and references is almost 150 000 words.

If I were asked how I pictured my brain, I guess I would say that I pretty much see it as a type of computer, with my memory, such as it is, being a card index system; analogous, if we continue with the computer metaphor, based on, in my case, my card index files and EndNote 🙂 I am, of course, not alone in picturing the brain as a computer, although I suspect that not as many picture themselves riffling through a card index drawer.

Those of you who read my blog, will know that I am a great fan of the history of science, in my case the history of entomology*, so Matthew’s magnum opus, really hits the spot as far as I am concerned, ranging as it does from 4000 BC to the present day. Being a product of my time and having cut my science-fiction teeth on Isaac Asimov and his positronic brain, I have always thought of my brain as assort of wet computer, but up until the 17th Century, feelings and thoughts were generally thought to emanate from the heart.  As Matthew points out – words and phrase like ‘learn by heart’, ‘heartbroken’, ‘heartfelt’ and similar highlight this, even though centuries prior to this, there was an acceptance that the brain was important to human function. Once the connection between the nervous system, the brain and the thoughts and actions of the human body and mind were made, then began the attempts to explain how it all worked.   What I hadn’t really thought about until I read this book, but should of, was that the way in which we perceive the working of the brain and nervous system, is very much shaped by the technology prevalent at the time. So brains went from being clockwork, pneumatic and hydraulic, the nerves being likened to pipes, electrical circuits and even akin to the telegraph. Apropos of the electrical circuit idea, I was amused to discover that one of the important proponents of this theory was an entomologist, Alfred Smee, who worked on aphids and virus transmission. We aphidologists get everywhere.

To me, one of the wonderful thing about this book, leaving aside the very accessible writing style, is how often I said to myself “Wow, I didn’t know that”.  My wife got very tired of me reading out excerpts 🙂

Do you remember generating static electricity when you were at school by rubbing a glass rod with a woollen cloth?  Well, how about the ‘hanging boy’ experiment commonly performed in the mid-1700s in which a boy was suspended from the ceiling and rubbed with a glass tube upon which feathers would miraculously rise up and stick to him?

How about Henry Molaison who in 1953 had his severe epilepsy ‘cured’ by having his hippocampus, amygdala and the entorhinal cortex (basically a lobotomy) removed.  From that day on until his death in 2008, Henry only lived in the now.  He had no yesterdays.

Did you know that if you cut the corpus callosum into two (another attempt at curing epilepsy), you end up with a person with two ‘brains’ not quite the same as the Steve Martin film, but the result is two minds in the same body. In the early months post-treatment, the patient experienced some conflict between the two sides of his brain; his hands would work in different ways when pulling up his trousers or doing up his belt. “These conflicts gradually died down, as each version of himself, hot used to sharing a body (although neither mind was aware of the other’s existence)”

I have always been quite happy with the idea of the brain being a computer, as I think, most people are. Matthew, however, feels that this latest metaphor is no longer valid and that we must think of the brain and how it functions very differently. You will need to read the book to find out exactly what he thinks this. He is, however, very sure that neuroscientists would make more progress in understanding how human brains worked if they studied the simpler brains of insects. SAs an entomologist, I am in total agreement 🙂

I could go on and on, but I won’t.  My feelings about this book have been very aptly summed up by Adam Rutherford who among other words of praise, says it is a masterpiece. 

I am in total agreement. Buy it and read it from cover to cover, you won’t regret it. At only £12.99 it is a real bargain.

Finally, thank you Matthew for taking the time out of your busy life to research and produce this book.  I, for one, very much appreciate it.

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Booze, sweat and blood – the birth of a paper

Of my top five most cited papers two are reviews, two are opinion pieces and one is a ‘real’ paper.  I have written about the serendipitous event that resulted in my second most cited paper (Leather, 1988), but now it is the turn for Number 5 to make the headlines 🙂 Number 5 (Ward et al., 1998), is a ‘real’ paper in that it tests an hypothesis and is based on data. It would, however, almost certainly never have come into existence if my friend and former lab mate, Seamus Ward, hadn’t come to visit me at Silwood Park in the spring of 1997.

Seamus was in the year below me in Tony Dixon’s lab, originally taken on to work on the maple aphid, but it transpired that his life history traits were not suited to maintaining host plants and aphid cultures.  Luckily it turned out that his true talents were in the area of theory and mathematical ecology; when you were talking to him about your aphids and what they were doing Seamus would sit there turning your description into equations. He thus ended up doing a PhD looking at life-history traits in aphids.  I make no claims to being mathematically oriented, but do take a quiet pride in being pretty good at running practical experiments and this made for a good partnership in the group, in that Seamus would come to me when he needed some experimental support (real data). This was mutually beneficial and resulted in papers we would not necessarily have written otherwise (Leather et al., 1983; Ward et al., 1984).

Having not seen Seamus for some time, since finishing his post-doc in the mid-1980s, he had been based in Australia at the University of La Trobe, we were reminiscing about old times. I happened to mention that I had fairly recently examined one of Tony Dixon’s PhD students who had been working on the carrot-willow aphid, Cavariella aegopdii and the evolution of aphid life-cycles (e.g. Kundu & Dixon, 1993, 1995). This of course got us on to talking about host alternation and why, if it is so risky, (there were estimates of less than 1% surviving the journeys between hosts (Taylor, 1977)), some aphid species. albeit only 10%, had adopted that strategy. In another paper, Tony and Raj had suggested that even if only 1 in 10 000 survived

The words that inspired us  – from Dixon & Kundu, 1994)

the migration from host to host, the high fecundities that host alternating aphids can achieve on their primary hosts (Leather & Dixon, 1981), would make it worthwhile (Dixon & Kundu, 1994). This got us thinking – how many aphids did actually make it and could we work it out?  We discussed this for a while over a beer, (we were in the Silwood Bar at the time), and Seamus decided that what we needed were some data of numbers of aphids on the ground and the number of aphids in the air at the same time. As it happened, I had a ten-year run of bird cherry aphid data on their primary host, Prunus padus trees in Roslin Glen (Scotland) (from my bird cherry aphid side project) and as a subscriber to the Rothamsted Aphid Bulletins, I had in my office, copies of the weekly aphid bulletins for the nearest suction trap to Roslin Glen, East Craigs.  This was enough for us to get started.

The bird cherry aphid side project data – still with me today and more analysis yet to be done 🙂

An example of the old paper version of the weekly aphid bulletin – I now subscribe electronically – a great resource https://insectsurvey.com/aphid-bulletin “The Rothamsted Insect Survey, a National Capability, is funded by the Biotechnology and Biological Sciences Research Council under the Core Capability Grant BBS/E/C/000J0200.”

The next day I started collating the field data and Seamus started to model.  We were totally engrossed and kept at it all day, breaking only for meals and coffee. After dinner, armed with a bottle of whisky and bubbling with ideas we returned to the computer and Seamus started taking me through his model and fitting the data.  Following the intricacies of the model was not easy for me and made my brain work so hard that my forehead started to sweat 🙂 Sometime near midnight, the bottle of whisky was empty, we had a working model and could put a figure on how many migrating aphids made it from the secondary host to the primary host – 0.6%.  Now, all we needed to do was to get the official aphid and weather data from the East Craigs suction trap and write the paper, which with the collaboration of Richard Harrington and Jon Pickup of Rothamsted Research Station and East Craigs respectively, we successfully did, the paper being submitted in August 1997, and appearing in early 1998 (Ward et al., 1998). In case you were wondering how many bird cherry aphids make it from the secondary host back to the primary host, for every 1000 that take-off, 6 make it, so less than Roy Taylor’s estimate but more than the number that Raj and Tony suggested were needed to make host alternation viable.

So that is the booze and the sweat accounted for, but what about the blood? I had, as an undergraduate, become a regular blood donor and the day after our marathon data crunch, was my scheduled blood donation.  That sunny morning, and somewhat hung-over, I walked across to the blood wagon, conveniently parked outside my office, made my donation and after my biscuit and cup of tea, headed back to my office.  As I was passing the toilets, I felt the need for a pee, so nipped in to relieve myself, stood at the communal urinals, unzipped and started to pass water, as I did so, my blood pressure dipped and I started to faint, my last thought before I passed out was that I didn’t want to fall face down in the urinal gutter, so pushed away from the wall with one hand. 

Not the actual urinal (they have long since been replaced) but this gives you the idea of what I didn’t want to fall into. Image source

I woke up some time later on the floor bleeding copiously from a head wound caused by me falling across one of the wash basins.  To cut a long story short, I was rushed to the local hospital, my head repaired, and, as I had a post-donation faint, no longer allowed to donate blood.  On the plus side, the paper has been very successful and I have an amusing after-dinner story to tell and the scar to prove it 🙂


Dixon, A.F.G. & Kundu, R. (1994) Ecology of host alternation in aphids. European Journal of Entomology, 91, 63-70.

Kundu, R. & Dixon, A.F.G. (1993) Do host alternating aphids know which plant they are on? Ecological Entomology, 18, 61-66.

Kundu, R. & Dixon, A.F.G. (1995) Evolution of complex life cycles in aphids. Journal of Animal Ecology, 64, 245-255.

Leather, S.R. & Dixon, A.F.G. (1981) Growth, survival and reproduction of the bird-cherry aphid, Rhopalosiphum padi, on it’s primary host. Annals of Applied Biology, 99, 115-118.

Leather, S.R. (1988) Size, reproductive potential and fecundity in insects: Things aren’t as simple as they seem. Oikos, 51, 386-389.

Leather, S.R., Ward, S.A. & Dixon, A.F.G. (1983) The effect of nutrient stress on life history parameters of the black bean aphid, Aphis fabae Scop. Oecologia, 57, 156-157.

Taylor, L.R. (1977) Migration and the spatial dynamics of an aphid, Myzus persicae. Journal of Animal Ecology, 46, 411-423.

Ward, S.A., Leather, S.R. & Dixon, A.F.G. (1984) Temperature prediction and the timing of sex in aphids. Oecologia, 62, 230-233.

Ward, S.A., Leather, S.R., Pickup, J. & Harrington, R. (1998) Mortality during dispersal and the cost of host-specificity in parasites: how many aphids find hosts? Journal of Animal Ecology, 67, 763-773.


Filed under Aphids, Science writing

Pick & Mix 60 – beetles, horses, cherries, butterflies, Scrabble, Monarchs and more

Reconnecting with my land – the impact of the Enclosure Acts on the English landscape

Japan’s cherry blossom viewing parties – the history of chasing the fleeting beauty of sakura and if you want an amusing travel book based around this, then I thoroughly recommend reading Hokkaido Highway Blues by Will Ferguson

James Harbeck (Sesquiotica) on life lessons learnt from Scrabble

Extinction and hope –  On the difficulties of reintroducing extinct butterfly species

There are still some farms in the UK using horses instead of tractors – it is good for soil health  but can it be profitable?

Poo, what is that smell? Some male butterflies make their mates stink to keep away potential rivals

Take care when buying wildflower mixes – some aren’t what they seem

Richard EdenThe alchemist, who became a cosmographer

Beetles in amber – a story of early interactions between insects and flowers

Migrating Monarch butterflies travel about 30-40 km a day so if you want you can keep up with them on your bike – Biking 10,000 miles with Monarchs

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Filed under Pick and mix

Data I’m never going to publish – factors affecting sycamore flowering and fruiting patterns

As a teenager I used to have a favourite thinking place, underneath a large beech tree half-way down the school drive.  I used to watch the activities of my school mates, while contemplatively chewing beech nuts (my school friends found this mildly disgusting).

Some years beech nuts were much easier to find than others; although I didn’t realise it at the time, this was my introduction to the phenomenon of masting.  At this point I had better fill you in on the basics of tree reproduction. Like most plants, trees reproduce by producing flowers that are pollinated, depending on the species, by vertebrates, insects or the wind. The fertilised flowers then produce seeds that are housed in what we term fruit or cones, and which in many cases aid their dispersal. Reproduction is energetically a costly process, reserves channelled to reproduction cannot be use for growth and defence.  Trees have evolved three different approaches to this problem. Some trees produce a moderate number of seeds in most years, others have an Irregular fruiting pattern and some, such as beech and oak, have strongly periodic fruiting patterns, “mast” years.  Interestingly (my wife hates me starting sentences off like this), trees that mast are wind pollinated.

Beech (Fagus sylvatica) mast production over a sixteen year period in England. Data from Hilton & Packham (1997

You might wonder why, if reproduction is costly, that some trees are ‘willing’ to expend so much energy in one go.  There are two schools of thought regarding this. One, which I find fairly convincing, is the “predator satiation” hypothesis (Janzen, 1971).  This basically says that the trees, by having on and off years, starve their specialist seed predators in the off years, thus reducing predator pressure by killing lots of them off. In the mast years, there are enough seeds to feed the surviving predators and produce another crop of trees.  A more recent, and less exciting suggestion (to me anyway), is that if the trees have a mass synchronised flowering effort, i.e. a mast year, then the chances of being pollinated are greatly increased (Moreira et al., 2014).

People tend to associate masting with trees that produce heavy fruit, acorns, hazel nuts and beech nuts for example, and I was no exception, so it wasn’t until a couple of years (1995) after I started my mega-sycamore study at Silwood Park that I had a bit of a revelation. I realised that not all of the trees flowered and that there seemed to be a lot fewer seeds that year than I remembered there being the year before. Sycamore seeds come equipped with two little wings (they are wing dispersed) and occur in little bunches (infructescences) so are quite noticeable.

Winged sycamore seed and ‘bunch’ of sycamore fruit

My sycamore study was one of my many side projects set up to satisfy my’ satiable curiosity’ and I had, at the time thought that I had made sure I was measuring everything that could possibly interact with the aphids feeding on the trees. I had, however, somehow overlooked sycamore flower production 🙂 I had taken into account that in some years the sycamore aphid can be present in huge numbers and and I was well aware from the work of my PhD supervisor

Sycamore aphids emerging in spring – some years you can see even more on the newly flushing buds

Tony Dixon, that the aphids can cause substantial losses to tree growth (Dixon, 1971), so had included tree girth and height measurements into my massive data collection list. Strangely, however, despite knowing from my work with

The effect of the sycamore aphid, Drepanosiphum platanoidis, on leaf area of two sycamore, Acer pseudoplatanus, trees over an eight year period (Dixon 1971).

the bird cherry-oat aphid Rhopalosiphum padi, that even quite low numbers of aphids could have substantial negative effects on cherry production (Leather, 1988), I had totally overlooked sycamore flowering and seed production. I am just thankful, that I only missed three years of flowering data 🙂

The effects of bird cherry aphid infestation on reproductive success of the bird cherry, Prunus padus (Leather, 1988)

Unlike the rest of my sycamore data set, the flowering data collection was actually set up to test a hypothesis; i.e. that aphid numbers affected flowering and seed set. Sycamore is in some ways similar to the well-known masting species such as oak and beech in that it is (jargon coming up) heterodichogamous. All flowers are functionally unisexual and appear sequentially on a single inflorescence. The inflorescences can however be either protandrous, i.e. male anthesis takes place before the stigmas become receptive, or protogynous where the reverse sequence takes place. Where it differs from the typical masting species is that is produces wind dispersed seeds and is wind and insect pollinated; oak, beech and hazel are entirely wind pollinated.  Pierre Binggelli, then based at the Unibersity of Ulster, hypothesised that protandrous trees may suffer less herbivore damage than protogynous trees (Binggeli, 1992). He suggested that protogynous trees, having less energy available to invest in defensive chemistry, are more attractive to insect herbivores, particularly chewers. On the other hand, sycamore trees that have been subject to previous insect infestation have fewer resources available to produce female flowers, become protandrous and avoid infestation by herbivores the following year. Presumably the next year, having escaped insect attack by being protandrous they should become protogynous again. So, if I wanted to test this hypothesis, I needed to learn how to sex sycamore flowers. Despite a handy guide that I came across (Binggeli, 1990), ) I found it almost impossible, to do, so

A. Protogynous inflorescence (female II flowers of Mode G are male II in Mode B). B. Protogynous infructescence, Mode B. C. Protogynous infructescence, Mode G. D. Protandrous inflorescence.
E. Protandrous infructescence. F. Vegetative shoot, G. Flowering shoot (Mode E).
H. Fruiting shoot (Flowering Modes B,C,D & G). (From Binggeli, 1990)

contacted Pierre, who very kindly agreed to check some of my ‘guesses’ for me.  Despite this help, I still found it very difficult so opted (very unwisely as it turned out) to collect fruit samples from each tree, put them in paper bags, and bring them back to the lab for sexing at a later date.  As you have probably guessed, I ended up with lots of paper bags which I then, not very cleverly, stored in plastic bin bags.  This went on for several years as I kept putting off the day when I would have to sit down and sex several thousand bunches of sycamore fruit. Then came the happy disastrous day when I came back from holiday to find out that the cleaners had disposed of my bin bags. To tell the truth I was not that upset as it gave me an excuse to stop collecting the fruit samples and reduced my feelings of guilt about having huge piles of unsexed sycamore fruit bunches cluttering up the lab 🙂 I did, of course, carry on counting the number of flowers on the trees, which was much easier data to collect and analyse.

I reluctantly ended my study in 2012 when I left Silwood Park for pastures new, but despite this I still haven’t analysed all my sycamore data, although I was very happy a couple of years ago when a PhD student from the University of Sheffield (Vicki Senior) volunteered to analyse some of my sycamore aphid data which was published last year (Senior et al., 2020). The winter moth data and orange ladybird data are also being analysed by a couple of my former students and hopefully will also be published by next year.

So what does the sycamore fruiting data show? Well, first, despite sycamore being reproductively somewhat atypical of other masting trees species, I would contend that my 17-year data set of sycamore fruit production looks remarkably similar to the Hilton and Packham beech masting data set. I am thus confident in stating that sycamore is a masting species.

Mean sycamore fruit production at Silwood Park, averaged from 52 trees 1996-2012,

Am I able to link sycamore seed production with aphid abundance, is the fruiting pattern a result of herbivory?  I can’t test Pierre Binggeli’s hypothesis about sex changing trees, because I lost the data, but I can try and see if aphid infestation affects fruit production. The two most common aphid species on the Silwood Park sycamore trees are the sycamore aphid Drepanosphum platanoidis and the maple aphid, Periphyllus acericola.  

Mean sycamore aphid and mean maple aphid loads (average annual counts per 40 leaves from all trees) 1996-2012.

They can both occur in high numbers, but in general, the average numbers of P. acericola are much higher than D. platanoidis. The reason why P. acericola has much higher numbers is a result of its over-summering strategy.

Over-summering morphs of the sycamore and maple aphid. Images from https://influentialpoints.com/Gallery/Drepanosiphum_platanoidis_common_sycamore_aphids.htmhttps://influentialpoints.com/Gallery/Periphyllus_acericola_Sycamore_Periphyllus_Aphid.htm#other

While the sycamore aphid spends the summer aestivating (basically a summer version of hibernation in that metabolism is reduced and reproduction ceases), the maple aphid produces a huge number of nymphs, known as dimorphs, which over-summer in dense, immobile aestivating colonies.  The sycamore aphid can escape predators by flying off the leaves if disturbed, the maple aphid dimorphs on the other hand, rely on their huge numbers to ensure survival of some of them over the summer to resume development and reproduce as autumn approaches, a form of predator satiation. They thus suffer a huge reduction in numbers compared with the sycamore aphid. (I must publish that one day). This makes drawing conclusions about the of herbivory (aphid feeding) on the trees a bit difficult.

Mean combined aphid load, showing how the number of dimorphs of the maple aphid skew the perceived aphid load.

Given that Tony Dixon showed that sycamore aphids cause a significant reduction in tree growth (Dixon, 1971), I

Relationship between mean combined aphid load (sycamore and maple aphid) and mean sycamore fruit production.

expected to see a negative relationship between aphid numbers and fruit production. What I did find was that there was a significant positive relationship between sycamore aphid numbers and fruit production, i.e. the more sycamore aphids, the more fruit produced, whereas with the maple aphid it was the other way round, more maple aphids, fewer fruit. If I combined the aphid loads, then the relationship becomes significantly positive, the more aphids you get the


Relationship between mean combined aphid load and the number of sycamore fruit produced the following year.

significantly negative relationship between aphid numbers and sycamore fruit production, but as I pointed out earlier this is driven by the preponderance of maple aphid dimorphs in the summer. You might also argue, that rather than looking at aphid numbers and sycamore fruit production in the same year, I should be comparing aphid numbers with fruit production the following year, i.e. a lag effect. I did indeed think of this, and found that there was, for both aphid species, no significant relationship between aphid numbers the previous year and fruit produced the following year. In fact, if I was an undergraduate student I would point out that there was a positive trend between aphid numbers and fruit production 🙂  If I do the same analysis using the combined aphid load, then the relationship becomes significantly positive, the more aphids you get the more sycamore fruit you get the following year which although counter-intuitive fits with the idea that stressed trees tend to produce more offspring (seeds) (Burt & Bell, 1991) and given that we know from Tony Dixon that the sycamore aphid causes a significant reduction in growth (Dixon, 1971) which is an indication of plant stress (Grime, 1979) makes perfect sense. 

Relationship between mean combined aphid load and the number of sycamore fruit produced the following year.

Instead of mean aphid load, perhaps we ought to be thinking about aphid occurrence at crucial times of the year for the tree, for example budburst. If you go back to the top of the page and look at the photograph of the infested buds you can see that there can be a huge number of aphids present at this time of year just when the trees are starting to wake up and put on new growth. Any interference to the uptake of nutrients at this phase of their life cycle could be detrimental to fruit production.  One way to measure this is by looking at the date the first aphids appear on the buds in the expectation that the earlier the aphids start to feed, the bigger their impact on the trees. Sure enough, the earlier the aphids start feeding, the lower the number of fruit produced.

Significant negative relationship between date of first appearance of aphids on the buds and number of fruit produced in spring.

Although all the relationships I have discussed and shown are significant, the amount of variation is explained is pretty low (over 20% but less than 30%). The relationship that explains most of the variation in any one year is the size of the tree, the bigger the tree the more fruit it produces.

Relationship between size of sycamore tree and number of fruit produced (2009).

As a rule of thumb, the bigger a tree the older it is and older trees have more resources and can afford to produce more offspring than younger smaller trees.

In conclusion, what I can say with confidence is that there is significant variability in sycamore fruit production between years and this is, in my opinion, evidence of masting events, and may be linked to the size and timing of aphid load but is moderated by the size and age of the trees. If you have any other suggestions please feel free to add them in the comments.

If anyone is interested in delving into the data in more depth I will be very happy to share the raw data and also the local weather data for the site.


Binggeli P. (1990) Detection of protandry and protogyny in sycamore (Acer pseudoplatanus L.) from infructescences. Watsonia,18, 17-20.

Binggeli P. (1992) Patterns of invasion of sycamore (Acer pseudoplatanus L.) in relation to species and ecosystem attributes. D.Phil. Thesis, The University of Ulster.

Burt, A. & Bell, G. (1991) Seed production is associated with a transient escape from parasite damage in American beech.  Oikos, 61,145–148.

Dixon, A.F.G. (1971) The role of aphids in wood formation. 1. The effect of the sycamore aphid, Drepanosiphum platanoides (Schr.) (Aphididae) on the growth of sycamore. Journal of Applied Ecology, 8, 165-179.

Hilton, G.M. & Packham, J.R. (1997) A sixteen-year record of regional and temporal variation in the fruiting of beech (Fagus sylvatica L.) in England (1980-1995). Forestry, 70, 7-16.

Hilton, G.M. & Packam, J.R. (2003) Variation in the masting of common beech (Fagus sylvatica L.) in northern Europe over two centuries (1800-2001). Forestry, 76, 319-328.

Janzen, D. H. (1971) Seed predation by animals. Annual Review of Ecology and Systematics, 2,465–492.

Leather, S.R. (1988) Consumers and plant fitness: coevolution or competition? Oikos, 53, 285-288.

Leather, S.R. (2000) Herbivory, phenology, morphology and the expression of sex in trees: who is in the driver’s seat? Oikos, 90, 194-196.

Moreira, X., L. Abdala-Roberts, Y. B. Linhart, and K. A. Mooney. (2014_. Masting promotes individual- and population-level reproduction by increasing pollination efficiency.Ecology, 95, 801–807.

Grime ., J.P. (1979) Primary strategies in plants, Transactions of the Botanical Society of Edinburgh, 43,2, 151-160.

Senior, V.L., Evans, L.C., Leather, S.R., Oliver, T.H. & Evans, K.L. (2020) Phenological responses in a sycamore-aphid-parasitoid system and consequences for aphid population dynamics; A 20 year case study. Global Change Biology, 26, 2814-2828.


Filed under Aphidology, EntoNotes

Let your dandelions and other flowering ‘weeds’ be

This last couple of weeks parts of my daily walks have been accompanied by, the to me, unwelcome din of motor lawnmowers as lots of my fellow villagers strive to turn their lawns into ecological deserts. One of my neighbours has, to my knowledge, cut his lawn five times since the beginning of March, me I’ve done my spring cut and that’s it until autumn.

An ecological desert 😦

This mania for close-cropped lawns, sometimes ‘artistically’ striped, is, I think, the fault of my grandparent’s generation, which took a municipal park attitude to gardens, especially the bit that the neighbours could see; close-cropped, weed-free grass with regimented flower beds, also equally weed-frees. Out of sight, back gardens could be less manicured, and depending on the space available, might include a vegetable garden (also scrupulously weed-free), and a patch of lawn to be used by children for ball games and other activities. Unfortunately they drummed this philosophy into their children, who in their turn, with only a few exceptions (me for one), passed this fetish on to my generation. Sadly, my father, a keen gardener, also espoused this view as did the parents of all my friends. I spent many a grumpy hour removing dandelions and thistles from our front lawn and flower beds at my father’s behest!

So what are these weeds that so many people seem to hate? To those growing crops of economic value, be they agricultural, horticultural or silvicultural, then I guess the following definitions are very reasonable and relatable.

Plants that threaten human welfare either by competing with other plants that have food, timber of amenity value, or by spoiling and thus diminishing the value of a product

Weeds arise out of the mismatch between the habitats we create and the plants we choose to grow in them

Begon, Harper & Townsend (1996)

A plant that originated under a natural environment and, in response to imposed and natural environments, evolved and continues to do so as an interfering associate with our desired plants and activities” Aldrich & Kremer (1997)

There are more tolerant descriptions of weeds available, which are much more in accord with my views:

What is a weed? A plant whose virtues have not yet been discovered” (Emerson, 1878)

, “A weed is but an unloved flower!” (Wilcox, 1911)

A plant condemned without a fair trial” (de Wet & Harlan, 1975)

I have, as I have mentioned several times already, been doing a lot of walking during the covid pandemic, or should it now be referred to as the Covid Pandemic? At this time of year, Spring, the early flowers of the hedgerows and roadside verges are alreday out; cherry plum (Prunus cerasifera), blackthorn or sloe (Prunus spimosa) and closer to the ground, but as equally pretty, daisies (Bellis perennis), dandelions (Taraxacum officinale), Lesser Celandines ( Ficaria verna (although some of you may know it as Ranunculus ficaria), and Wood Anemones (Anemonoides nemorosa). The latter two species, although relatively common, are unlikely to be found in the average garden, as they have fairly specific habitat requirements.  Daisies and dandelions on the other hand, are pretty much ubiquitous, although the former do not attract as much opprobrium from the traditional gardener as dandelions do. This is a great shame, as ecologically speaking dandelions are an extremely important resource for pollen and nectar feeding insects.

Given the concerns about the decline of insects in general over the last forty years, we should be celebrating the dandelion, not trying to eradicate it from our lawns. Just feast your eyes on some of the beauties that I have seen over the last few days.

Pollen beetles March 20th 2021

Male tawny mining bee Andrena fulva – Sutton March 25th 2021

Bumble bee, Sutton March 30th 2021

Seven spot lady bird, too early for aphids, Oulton Road March 30th 2021

Peacock butterfly in a very striking pose, Guild Lane, Sutton, April 3rd 2021.

I’m not alone in my love of dandelions 🙂

We shouldn’t forget the humble daisy either. It provides nectar to many butterfly species, including among others, the Green Hairstreak, the Grizzled Skipper, the Small Copper and the Small White. They are also important resources for honey bees (Raquier et al., 2015), bumblebees and hoverflies (Blackmore & Goulson, 2014).

A nice patch of daisies.

Domestic gardens, if managed correctly, have tremendous potential as reservoirs of insects and other invertebrates of ecological importance (Davies et al, 2009). The easiest thing that you can do to help the insects is to reduce the frequency at which you mow your lawn and grass verges. To sum it up in a nutshell, the less you move, the more flowers you get and the more flowers you get the more nectar and pollen feeding insects you make happy, some of which can be rare and endangered (Wastian et al., 2016).  

The less frequently you mow, the more flowers you get. The more flowers you get, the more bumblebees you get (George, 2008).

It is not just flower feeding insects that benefit from reducing your lawn mowing activities; grass feeding insects also benefit from longer grass ( Helden & Leather, 2005) and if, for some strange reason, you are not a great fan of bugs, just remember that the more bugs you have the more birds you will attract (Heden et al.,  2012). So do your bit to save the planet, be like me, only mow your lawn twice a year.


Aldrich, R.J. & Kremer, R.J. (1997) Principles in Weed Management. Panima Publishing Corporation.

Begon, M., Harper, J,L. & Townsend, C.R. ( 1996) Ecology, 3rd Edition, Blackwell Science, oxford.

Blackmore, L.M. & Goulson, D. (2014) Evaluating the effectiveness of wildflower seed mixes for boosting floral diversity and bumblebee and hoverfly abundance in urban areas. Insect Conservation & Diversity, 7, 480-484.

Davies, Z.G., Fuller, R.A., Loram, A., Irvine, K.N., Sims, V. & Gaston, K.J. (2009) A national scale inventory of resource provision for biodiversity within domestic gardens. Biological Conservation, 142, 761-771.

De Wet, J.M.J., Harlan, J.R.  (1975) Weeds and domesticates: Evolution in the man-made habitat. Economic Botany, 29, 99–108.

Emerson, R.W.(1878) The Fortunes of the Republic. The Riverside Press, Boston, USA.

Garbuzov, M., Fensome, K.A. & Ratnieks, F.L.W.  (2015)   Public approval plus more wildlife: twin benefits of reduced mowing of amenity grass in a suburban public park in Saltdean, UK. Insect Conservation & Diversity, 8, 107-119.

George, W. (2008) The Birds and the Bees: Factors Affecting Birds, Bumblebees and Butterflies in Urban Green Spaces, MSc Thesis, Imperial College, London.

Helden, A.J. & Leather, S.R. (2005) The Hemiptera of Bracknell as an example of biodiversity within an urban environment. British Journal of Entomology & Natural History, 18, 233-252.

Helden, A.J., Stamp, G.C. & Leather, S.R. (2012) Urban biodiversity: comparison of insect assemblages on native and non-native trees. Urban Ecosystems, 15, 611-624.

Lerman, S.B., Contostac, A.R., Milamb, J. & Bang, C. (2018) To mow or to mow less: Lawn mowing frequency affects bee abundance and diversity in suburban yards. Biological Conservation, 221, 160-174.

Requier, F., Odoux, J., Tamic, T.,Moreau, N., Henry, M., Decourtye, A. & Bretagnolle, V. (2015)  Honey bee diet in intensive farmland habitats reveals an unexpectedly high flower richness and a major role of weedsEcological Applications, 25, 881–890.  

Wastian, L., Unterweger, P.A.& Betz, O. (2016) Influence of the reduction of urban lawn mowing on wild bee diversity (Hymenoptera, Apoidea). Journal of Hymenoptera Research, 49, 51–63.

Wilcox, E.W. (1911) Poems of Progress and New Thought Pastels. London: Gay & Hancock, 1911.


Filed under EntoNotes

Pick & Mix 59 – countryside and colonialism, climate change, urban greening, native trees, natural history and public rights of way

Corinne Fowler on colonialism’s imprint on the British countryside.

I’m a climate scientist – here’s three key things I have learned over a year of COVID

Ancient leaves preserved under a mile of Greenland’s ice – and lost in a freezer for years – hold lessons about climate change

Why entomologists kill – understanding the need for collections

In case of emergency — break glass – Richard Jones on the trials and tribulations of trying to copy a bank note 🙂

Torino – showing the world how to make a green city

Perfectly explains why I prefer real books to e-books – The Multisensory Experience of Handling and Reading Books

Plant native, save insects – also in the UK it will benefit birds as well (if you want a copy email me)

Time to make nature studies a compulsory school subject – before it’s too late – and here is a blog post by me about the same subject from last year

Britain’s ancient footpaths could soon be lost forever, and here is a blog post by me about the same subject written a few weeks earlier – ahead of the curve that’s me 🙂


Filed under Pick and mix

Bee’s knees, a gnat’s whisker, knee-high to a grasshopper, a flea in your ear and other insect idioms

Idiom a group of words established by usage as having a meaning not deducible from those of the individual word

I’m fond of saying that I have been an entomologist since I was knee-high to a grasshopper, which I automatically expect my audience to understand means since I was very young.

Knee-high to a grasshopper?

What I didn’t know was that this well known phrase only dates from about 1850 and replaced the earlier knee-high to a mosquito or bumblebee or splinter. I can find no explanation as to why this change occurred; perhaps it was because someone felt sorry that the Orthoptera didn’t have any idioms associated with them as opposed to the Hymenoptera which dominate the insect idiom world.  “Rightly so” I can hear the Hymenopterists exclaiming, “after all there are more of them than any other Order” (Forbes et al., 2018).


When I go into the Entomology Lab I expect it to be a “hive of activity” where everyone is as “busy as a bee” and there is a “real buzz”.

Strangely enough, despite the hymenopteran references I would hope that my students are all working on aphids, but then some people would say that I have “a bee in my bonnet” about them and I will definitely be making “a beeline” to the aphid cultures shortly after I arrive as I think that aphids are the “bee’s knees” when it comes to insects 🙂 I can get quite

waspish” when I hear people making disparaging remarks about aphids although I would never describe myself as getting as “mad as a hornet” over the matter. In fact I love aphids so much that if someone asks me why I do, I will never say “none of your beeswax” and you might think that I “have ants in my pants”  as I wait for an opportune moment to explain about the “birds and the bees” when applied to aphid reproduction.


Erica McAlister author of The Secret Life of Flies will tell you that flies are where it’s at and it is certainly worth being “a fly on the wall” when Erica starts talking about flies in general.

Unless you have “the attention span of a gnat” you will be enthralled by her anecdotes. The only “fly in the ointment” is that some of her flies have absolutely disgusting habits.  Erica herself, “wouldn’t hurt a fly”, no matter how unsavoury its lifestyle. I have heard it said, that sometimes, the less strong-stomached members of her audience, can be seen “dropping like flies”.  I confess that I am a bit worried that if Erica reads this I will come within a “gnat’s whisker” of being slapped in the face 🙂 Speaking of gnats, I just found this expression in a detective novel published in 1932 (Wilkinson, 1932) “antiquated gnat of a custom”, but have not been able to find out exactly what it means and its origin – any suggestions welcomed.


No one could describe me as being as “gaudy as a butterfly” as my usual attire is a pair of blue jeans, a shirt with rolled up sleeves and a pair of desert boots, although I do have some butterfly-themed clothing.

Gaudy as a butterfly – nope

The previous sentence reminds me that I have written about dress codes in an earlier post,  and the role this might have in curing the feeling of “having butterflies in one’s stomach” before giving a talk. Speaking of nervousness coupled with shyness, something many of us feel in social situations, which can cause some of us to imbibe liquids containing alcohol, I find that even after a few drinks I am not much of a “social butterfly”, a garrulous drunk is probably the best description 🙂

Everything got a little bit hazy


Now you might think that the Coleoptera, having, at the moment, the most species described would have provided us with a plethora of beetle inspired idiomatic expressions. Sadly as I “beetle along” in my “beetle crushers” I very soon come to the end of their influence on idiomatic English.  Just to make any coloepterist who might be reading this feel a bit better, the narrator in Rudyard Kipling’s Stalky & Co (a humorous novel about late Victorian schoolboys) is nicknamed Beetle, possibly because Kipling, like me, could be described as “beetle-browed”.

Beetle-browed, although my wife has been known to describe them as looking like furry caterpillars

Siphonoptera (Mecoptera)

Leaving the beetles behind us we come across the Siphonoptera, the fleas. Some people might say I have “a mind like a flea” but did you know that fleas have been recently re-classified as parasitic scorpionflies (Tihelka et al., 2020), which might make those people who say they “wouldn’t hurt a flea” think twice about using that phrase or the term “fleabag”.

Insects in general

As someone whose favourite insects are Hemipteran, I would love to say that the greatest number of insect idioms are provided by the true bugs, but that would be untrue. In general, when non-entomologists use the word bug, they mean insects in general, a particular “bugbear” of mine. I would go as far as to say that it really “bugs me”. In fact, I’d love to put “a bug in someone’s ear” about it and if I came across a journalist using bugs correctly I’d certainly go “bug-eyed”. I’m writing this in my warm centrally-heated house, feeling as

Not only snug as a bug but an example of one of my bugbears!

snug as a bug in a rug” although once this pandemic is over I’m pretty sure that the “travel bug” will bite me, and I’ll be heading off to France to enjoy great food, good wine and plenty of sunshine.


Forbes, A.A., Bagley, R.K., Beer, M.A. et al. (2018) Quantifying the unquantifiable: why Hymenoptera, not Coleoptera, is the most speciose animal order. BMC Ecology, 18, 21.

Tihelka , E., Giacomelli, M.,Huang, D., Pisani, D., Donoghue, P.C.J. &  Cai, C. (202o) Fleas are parasitic scorpionflies. Palaeoentomology,3, 641–653.

Wilkinson, E. (1932) The Division Bell Mystery, George Harrap & Co Ltd, London. Reprint available via the British Library Crime Classics series



a bee’s dick – a very small amount https://stronglang.wordpress.com/2017/08/21/a-new-cooking-measurement/

a hive of activity – a place/situation where everyone is busy

ants in your pants/antsy – agitated or restless due to nervousness or excitement

as busy as a bee – very busy

as mad as a hornet – very angry

bee’s knees – an excellent person or thing, of the highest quality

birds and the bees – a euphemism for the basic facts about reproduction as told to a child

none of your beeswax – none of your business

to have a bee in one’s bonnet – to be preoccupied/obsessed with something

to make a beeline – to move swiftly and directly towards something or someone


dropping like flies – dying or collapsing in large numbers, giving up on or pulling out of an endeavour

fly in the ointment – a small problem which nonetheless spoils the whole plan

fly on the wall – an unnoticed witness

wouldn’t hurt a fly – used to emphasize how inoffensive and harmless a person or animal is


as gaudy as a butterfly – very colourful

social butterfly – a person who is socially dynamic, successful at networking, charismatic, and personally gregarious

to have butterflies in one’s stomach – to feel nervous/anxious/excited in your stomach


Beetle along – hurry, scuttle

Beetle-browed – having shaggy and projecting eyebrows

Beetle crushers – large shoes/boots

Siphonoptera (Mecoptera)

a flea in (someone’s) ear – an unwelcome idea or answer

mind like a flea – jumping from one idea to another

fleabag – a dirty or shabby person or animal, typically one infested with fleas or a seedy and dilapidated hotel

wouldn’t hurt a flea – gentle and kind

Insects in general

as snug as a bug (in a rug) – very comfortable/cosy

bug-eyed – with bulging eyes, astonished, amazed

to bug someone – to annoy someone

to put a bug in someone’s ear about something – to give someone a hint about something

travel bug – a strong desire to travel; an obsessive enthusiasm for or addiction to travellin;


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