Tag Archives: beetles

Planes, trains and automobiles – insect killers?

I couldn’t not use this – it is (sadly) one of my favourite films 😊

Anyone who has driven (or walked) along a road will have come across roadkill, be it squirrels, pheasants, badgers, deer or even something more exotic, perhaps it us only us entomologists who notice the squashed invertebrates ☹

Dead carabids and mayflies Shay Lane, Staffordshire, 8th June 2021

But, lets leave the roadkill for a moment, and in the spirit of the title of the film, start in the air. The first thing I discovered when I started to search for the effects of aircraft on insects is the paucity of literature on the subject – it turns out that people are much more interested in stopping disease carrying insects being transported by air or, and coming as a bit of a surprise to me, stopping insects causing plane crashes (House et al., 2020; Grout & Russell, 2021). The aircraft industry is so concerned about the physical dangers posed to ‘planes by insects that NASA actually have a Bug Team dedicated to developing insect proof aircraft.

I am, however, more concerned about how dangerous aircraft are to insects. First, we need to know how many insects are up there and what the probability of them being struck and killed by aircraft is. I’m guessing that bug strike is pretty common, otherwise NASA wouldn’t have a Bug Team. The majority of insects in the air are found at 300-600 m, although this does vary in relation to time of day (Reynolds et al., 2005). Getting a figure for the actual number of insects in the air is as you might expect, actually quite difficult.  The first attempt to trap and collect insects using an aircraft was in 1926 in Louisiana (USA) using a specially designed trap (Glick, 1939).  These do not seem to have been particularly effective as 5 years of trapping, involving 1528 hours of flying, caught just under 30 000 insects (Glick, 1939).  Those of us who have operated pitfall traps for any length of time would consider this a very modest haul 😊

Glick (1939) The aircraft insect trap

That said, the exercise was obviously more hazardous than even collecting insects from roundabouts as this very laconic extract highlights:

 “The skill of the pilots who flew the collecting airplanes is evidenced by the fact that no fatalities occurred.  Only one major accident occurred, when a forced landing resulted in the destruction of the craft and injury to both the pilot (McGinley) and the writer. Such mishaps must be expected in a more or less hazardous undertaking.”

The distribution of catch number was very similar to that reported from the more recent UK study using radar (Reynolds et al., 2005) and is reinforced by this statement from the NASA Bug Team; “The reason we do these tests at low altitudes or do a lot of takeoffs and landings is because bug accumulation occurs at anywhere from the ground to less than 1,000 feet,” said Mia Siochi, a materials researcher at NASA Langley”.

Given the number of flights made globally and the investment being made into protecting aircraft from bug strike, I would assume that the number of insects being killed by aircraft worldwide is probably very high. I am sure that someone with the skill, time and inclination, can probably come up with a fairly realistic figure.  Over to you Dear Readers.

Next up, if we keep to the film title, are trains.  There has been a bit more work looking at the damage that trains do to insects, not a lot, but something is better than nothing.  Work collecting train kill from railway lines showed that snails were particularly vulnerable to being run over, similar to the effects on trail-following ermine moth caterpillars that I observed in Finland in 1981, with Ephemeroptera (Mayflies) in second place (Pop et al., 2020). This, as the authors suggest, was almost certainly due to the time of year and the presence of a lake nearby. Unfortunately no one has done the equivalent of a train splatometer which might be rewarding as these observations from correspondence in British Birds magazine suggest that locomotive engines are causing some mortality to flying insects.  Over to you Bug Life. How about getting the train companies to fit splatometers?

Finally, cars and their effect on insect life. There is anecdotal evidence out there, after all as drivers we have all seen moths in our headlights at night and used our windscreen washers and wipers to try and remove dried on insect corpses and their haemolymph from our front windscreens.

An observation by Ian Bedford

My front bumper – sadly (or perhaps not) much less insect spattered than in the past

Yes, anecdotally we know that insects are being hit by cars (see above) and on my front number plate, a couple of weeks ago (beginning of June) I counted 73 insects, mainly aphids after a 245 km trip. The problem as I see it, is quantifying the numbers killed and calculating the effect that this has on insect abundance. I have mentioned the splatometer in an earlier post which attempts to standardise the number plate counts and I am pleased to see that this has now been revived by Bug Life, and will hopefully carry on for many years. The idea behind this is that over the years we will be able to see if insect numbers as reflected by the change in numbers of splats are increasing, decreasing of remaining the same.  This will not, certainly as described, tell us how many insects are being killed by road using vehicles, although it would be possible if the data were collected over delineated stretches of road (Baxter-Gilbert et al., 2015).  It is not just flying insects that are killed by cars; not all flying insects fly across roads, many seem happy to walk to the other side, reckless as that may seem.

A brave, or possibly fool-hardy carabid beetle crossing the road – Guild Lane, Sutton, Staffordshire, 9th June 2021.

There have been enough studies done looking at the interactions between roads and insects for a review article to have been published fairly recently, although not all the papers deal directly with mortality effects (Munõz et al., 2015). Many studies have recorded the species affected and the number of dead individuals found but few have attempted to calculate what this means in total. Most studies, as we might expect, have been on large, easily identifiable charismatic species (Munõz et al., 2015) and it from these that we do have some idea of the magnitude of the mayhem caused by road traffic. Some of the figures are incredibly high. A survey of Odonata road kill, albeit near a wetland, of two 500 m stretches of dual carriageway in the Great Lakes region of the USA revealed that at least 88/km/day were being hit and killed by vehicles (Riffell, 1969).  Another study in the USA, this time on Lepidoptera, calculated that about 20 000 000 butterflies (mainly Pieridae) were killed in one week in September (McKenna et al., 2001). The most dramatic figures however, are those from a study in Canada which estimated that 187 billion pollinators (mainly Hymenoptera) are killed over the summer in North America (Baxter-Gilbert et al., 2015).  An unpublished study by Roger Morris (thank you Richard Wilson @ecology_digest for bringing this to my attention) also highlights the dangerous effects of cars on Hymenoptera). Despite the mounting evidence of the harm that road traffic does to insects there is remarkably little information about how this can be reduced, although I did find a paper that noted that if insects are struck by cars driving at speeds of 30-40 km/h they survive the crash whereas speeds greater than this prove fatal (Rao & Girish, 2007).  It might be possible to impose insect safe speed limits along stretches of road that go through sites of special insect interest (perhaps I should try and coin that acronym, SSII, as an additional/alternative term to SSSI (Sites of Special Scientific Interest), but I am not sure how amenable drivers would be to signs telling them to slow down because of insects😊, considering how few drivers slow down in response to the signs warning them about deer and other vertebrate hazards. Another option would be to design road vehicles so that the air flow across them pushes insects away rather than into them; this may already be fortuitously happening as Manu Saunders points in her interesting post about the ‘windscreen anecdote’.  That said, even if cars are more aerodynamic and less likely to splatter insects, the levels of road kill reported in the papers I have cited earlier, still imply that insects are being killed by traffic in huge numbers.

This one didn’t get stuck on a car, but died just the same – A519 outside Forton, Staffordshire, 15th June 2021

Even if we do accept that deaths down to direct impact with vehicles is lower than in the past, the roads on which we drive our cars are also having a negative effect on insect numbers. Roads, particularly those surfaced with tarmacadam, present an inhospitable surface to some insects which may make them reluctant to fly or walk across. It has been shown that bee and was communities can be different on different sides of a road (Andersson et al., 2017) as the road act as barriers, particularly for smaller species of bees (Fitch & Vaidya, 2021).

Despite the mortality that vehicles impose on insects, roads are not necessarily a totally bad thing for invertebrates; road verges, when sympathetically managed, can provide overwintering sites for a range of arthropod species (Saarinen et al., 2005; Schaffers et al., 2012) and some insect species seem to enjoy feeding on roadside vegetation because of the increased nitrogen content of the plants living alongside traffic (Jones & Leather, 2012).

Overall however, given the very high mortality rates directly associated with cars and other road traffic and the very real indirect effects caused by habitat fragmentation, it would seem that we have much to do to make roads safer for insects and other animals.

References

Andersson, P., Koffman, A., Sjödin, N.E. & Johansson, V. (2017) Roads may act as barriers to flying insects: species composition if bees and wasps differs on two sides of a large highway.  Nature Conservation, 18, 41-59.

Baxter-Gilbert, J.H., Riley, J.L., Neufeld, C.J.H., Litzgus, J.D., & Lesbarreres, D. (2015) Road mortality potentially responsible for billions of pollinating insect deaths annually. Journal of Insect Conservation, 19, 1029-1035.

Fitch, G. & Vaidya, C. (2021) Roads pose a significant barrier to bee movement, mediated by road size, traffic and bee identity. Journal of Applied Ecology, 58,1177–1186.

Glick, P.A. (1939) The Distribution of Insects, Spiders, and Mites in the air.  Technical Bulletin no. 673, USDA. https://naldc.nal.usda.gov/download/CAT86200667/PDF

Grout, A. & Russell, R.C. (2021)H Aircraft disinsection: what is the usefulness as a public health measure? Journal of Travel Medicine, 28, taaa124.

House, A.P.N., Ring, J.G., Hill, M.J. & Shaw, P.P. (2020) Insects and aviation safety: The case of the keyhole wasp Pachodynerus nasidens (Hymenoptera: Vespidae) in Australia. Transportation Research Interdisciplinary Perspectives, 4, 100096.

Jones, E.L. & Leather, S.R. (2012) Invertebrates in urban areas: a review. European Journal of Entomology, 109, 463-478.

McKenna, D.D., McKenna, K., Malcolm, S.B. & Berenbaum, M.R. (2001) Mortality of lepidoptera along roadways in Central Illinois. Journal of the Lepidopterist’s Society, 55, 63-68.

Melis, C., Olsen, C.B., Hyllvang, M., Gobbi, M., Stokke, B.G., & Røskaft, E. (2010) The effect of traffic intensity on ground beetle (Coleoptera: Carabidae) assemblages in central Sweden. Journal of Insect Conservation, 14, 159-168.

Munõz, P.T., Torres, F.P. & Megias, A.G. (2015) Effect of roads on insects: a review. Biodiversity & Conservation, 24, 659-682.

Pop, D.R., Maier, A.R.M., Cadar, A.M., Cicort-Lucaciu, A.S., Ferenți, S. & Cupșa, D. (2020) Slower than the trains! Railway mortality impacts especially snails on a railway in the Apuseni Mountains, Romania. Annales Zoologici Fennici, 57, 225-235.

Rao, R.S.P & Girish, M.K.S. (2007) Road kills: assessing insect casualties using flagship taxon. Current Science, 92, 830-837.

Reynolds, D.R., Chapman, J.W., Edwards, A.S., Smith, A.D., Wood, C. R., Barlow, J. F. and Woiwod, I.P. (2005) Radar studies of the vertical distribution of insects migrating over southern Britain: the influence of temperature inversions on nocturnal layer concentrations. Bulletin of Entomological Research, 95, 259-274.

Riffell, S.K. (1999) Road mortality of dragonflies (Odonata) in a Great Lakes coastal wetland. Great Lakes Entomologist, 32, 63-74.

Saarinen, K., Valtonen, A., Jantunen, J. & Saarnio, J. (2005) Butterflies and diurnal moths along road verges: does road type affect diversity and abundance? Biological Conservation, 123, 403-412.

Schaffers, A.P., Raemakers, I.P., & Sýkora, K.V. (2012) Successful overwintering of arthropods in roadside verges. Journal of Insect Conservation, 16, 511-522.

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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.

References

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 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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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.

References

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.

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Pick & Mix 45 – Sex, disease, food, insect art and much more

Do you want to stop the next pandemic?  Yes, then start protecting wildlife habitats

Why Latin names are important – nice informative post from Scottish Pollinators

Ray Cannon on insect tibial spurs –  much more than just decorative spines

Another great post from Ray Cannon, this time a lyrical account of the courtship behaviour of the Vinegar Fly

Interesting article on how biologists worked out the what and how of viruses

Runny honey, furry spinach and shiny apples – some fun food facts

Why are butterflies doing better this year? In Australia at any rate

Some fabulous insect art from Vietnamese artist Hoàng Hoàng

If beetles are on the front line of the global extinction crisis, then entomologists are on the front line of budget cuts. Halting plans to save invertebrates results in the least public outcry, especially if no one knows they’re there in the first place.

Crop domestication – perhaps plants evolved to exploit humans as seed dispersers?

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Pick and Mix 28 – some video treats

A very interesting, if somewhat gruesome video, of a botfly larva being removed from a human

Continuing with the fly stuff, here are some maggots having an evening meal 🙂 Seriously though, the article is all about using insects as food

And continuing with flies and food – don’t forget that bees are not the only pollinators

Now some hungry mosquitoes, which are of course. also flies

More flies – this time on how to stop them eating your wheat crop

Cockroach farming for food and medicine

Beetles like light too

Magnificent Monarchs in flight – a moving experience

A musical introduction to insect orders

A moving video from a teenage girl about insect extinction

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Global Insect Extinction – a never ending story

I have had an unexpectedly busy couple of weeks talking about declines in insect populations.  Back in November of last year I wrote a blog about the sudden media interest in “Insect Armageddon” and followed this up with a more formal Editorial in Annals of Applied Biology at the beginning of the year (Leather, 2018).  I mused at the time if this was yet another media ‘storm in a teacup’ but it seems that the subject is still attracting attention.  I appeared on television as part of TRT World’s Roundtable programme and was quoted quite extensively in The Observer newspaper on Sunday last talking about insect declines since my student days 🙂 At the same time, as befits something that has been billed as being global, a similar story, featuring another veteran entomologist appeared in the New Zealand press.

The TV discussion was quite interesting, the panel included Nick Rau from Friends of the Earth, Lutfi Radwan, an academic turned organic farmer, Manu Saunders from Ecology is Not a Dirty Word and me.  If they had hoped for a heated argument they were out of luck, we were all pretty much in agreement; yes insects did not seem to be as abundant as they had once been, and this was almost certainly a result of anthropogenic factors, intensive agriculture, urbanisation and to a lesser extent climate change.  Unlike some commentators who firmly point the finger at the use of pesticides as the major cause of the declines reported, we were more inclined to towards the idea of habitat degradation, fragmentation and loss.  We also agreed that a big problem is a lack of connection with Nature by large sections of the population, and not just those under twenty.  We also felt very strongly that governments should be investing much more into research in this area and that we desperately need more properly replicated and designed long-term studies to monitor the undeniable changes that are occurring.  I had, in my Editorial and an earlier blog post, mentioned this point and lamented the paucity of such information, so was pleasantly surprised, to receive a couple of papers from Sebastian Schuh documenting long-term declines in Hemiptera and Orthoptera in Germany (Schuh et al., 2012ab), although of course sad, to see yet more evidence for decreasing insect populations.

The idea that insects are in terminal decline has been rumbling on for some time; more than a decade ago Kelvin Conrad and colleagues highlighted a rapid decline in moth numbers (Conrad et al., 2006) and a few years later, Dave Brooks and colleagues using data from the UK  Environmental Change Network revealed a disturbing decline in the numbers of carabid beetles across the UK (Brooks et al., 2012).   In the same year (2012) I was asked to give a talk at a conference organised by the Society of Chemical Industry. Then, as now, I felt that pesticides were not the only factor causing the biodiversity crisis, but that agricultural intensification, habitat loss and habitat degradation were and are probably more to blame.  In response to this quote in the media at the time:

“British Insects in Decline

Scientists are warning of a potential ecological disaster following the discovery that Britain has lost around 7% of its indigenous insect species in just under 100 years.

A comparison with figures collected in 1904 have revealed that around 400 species are now extinct, including the black-veined white butterfly, not seen since 1912, the Essex emerald moth and the short-haired bumblebee. Many others are endangered, including the large garden bumblebee, the Fen Raft spider, which is only to be found in a reserve on the Norfolk/Suffolk border, and the once common scarlet malachite beetle, now restricted to just three sites.

Changes to the insects’ natural habitats have been responsible for this disastrous decline in numbers. From housing and industrial developments to single-crop farming methods, Britain’s countryside has become increasingly inhospitable to its native insects.”

I chose to talk about “Forest and woodland insects: Down and out or on the up?” I used data from that most valuable of data sets, the Rothamsted Insect Survey to illustrate my hypothesis that those insects associated with trees were either doing better or not declining, because of increased tree planting over the last fifty years.  As you can see from the slides from my talk, this does indeed seem to be the case with moths and aphids that feed on trees or live in their shade.  I also showed that the populations of the same species in northern Britain, where agriculture is less intensive and forests and woodlands more prevalent were definitely on the up, and this phenomenon was not just confined to moths and aphids.

Two tree aphids, one Drepanosiphum platanoidis lives on sycamore, the other Elatobium abietinum, lives on spruce trees; both are doing rather well.

Two more tree-dwelling aphids, one on European lime, the other on sycamore and maples, both doing very well.  For those of you unfamiliar with UK geography, East Craigs is in Scotland and Newcastle in the North East of England, Hereford in the middle and to the west, and Starcross in the South West, Sites 2, 1, 6 and 9 in the map in the preceding figure.

Two conifer feeding moth species showing no signs of decline.

On the up, two species, a beetle, Agrilus biguttatus perhaps due to climate change, and a butterfly, the Speckled Wood Pararge aegeria, due to habitat expansion and climate change?

It is important however, to remember that insect populations are not static, they vary from year to year, and the natural fluctuations in their populations can be large and, as in the case of the Orange ladybird, Halyzia sedecimguttata, take place over a several years, which is yet another reason that we need long-term data sets.

The Orange ladybird Halyzia sedecimguttata, a mildew feeder, especially on sycamore.

It is obvious, whether we believe that an ecological catastrophe is heading our way or not, that humans are having a marked effect on the biodiversity that keeps our planet in good working order and not just through our need to feed an ever-increasing population.  A number of recent studies have shown that our fixation with car ownership is killing billions of insects every year (Skórka et al., 2013; Baxter-Gilbert et al.,2015; Keilsohn et al., 2018) and that our fear of the dark is putting insects and the animals that feed on them at risk (Eccard et al.,  2018; Grubisic et al., 2018).  We have a lot to answer for and this is exacerbated by our growing disconnect from Nature and the insidious effect of “shifting baselines” which mean that succeeding generations tend to accept what they see as normal (Leather & Quicke, 2010, Soga & Gaston, 2018) and highlights the very real need for robust long-term data to counteract this dangerous and potentially lethal, World view (Schuh, 2012; Soga & Gaston, 2018).  Perhaps if research funding over the last thirty years or so had been targeted at the many million little things that run the World and not the handful of vertebrates that rely on them (Leather, 2009), we would not be in such a dangerous place?

I am, however, determined to remain hopeful.  As a result of the article in The Observer, I received an email from a gentleman called Glyn Brown, who uses art to hopefully, do something about shifting baselines.  This is his philosophy in his own words and pictures.

 

References

Baxter-Gilbert, J.H., Riley, J.L., Neufeld, C.J.H., Litzgus, J.D. & Lesbarrères, D.  (2015) Road mortality potentially responsible for billions of pollinating insect deaths annually. Journal of Insect Conservation, 19, 1029-1035.

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

Conrad, K.F., Warren. M.S., Fox, R., Parsons, M.S. & Woiwod, I.P. (2006) Rapid declines of common, widespread British moths provide evidence of an insect biodiversity crisis. Biological Conservation, 132, 279-291.

Eccard, J.A., Scheffler, I., Franke, S. & Hoffmann, J. (2018) Off‐grid: solar powered LED illumination impacts epigeal arthropods. Insect Conservation & Diversity, https://onlinelibrary.wiley.com/doi/full/10.1111/icad.12303

Estay, S.A., Lima, M., Labra, F.A. & Harrington, R. (2012) Increased outbreak frequency associated with changes in the dynamic behaviour of populations of two aphid species. Oikos, 121, 614-622.

Grubisic, M., van Grunsven, R.H.A.,  Kyba, C.C.M.,  Manfrin, A. & Hölker, F. (2018) Insect declines and agroecosystems: does light pollution matter? Annals of Applied Biology,   https://onlinelibrary.wiley.com/doi/full/10.1111/aab.12440

Keilsohn, W., Narango, D.L. & Tallamy, D.W. (2018) Roadside habitat impacts insect traffic mortality.  Journal of Insect Conservation, 22, 183-188.

Leather, S.R. (2009) Taxonomic chauvinism threatens the future of entomology. Biologist, 56, 10-13.

Leather, S.R. (2018) “Ecological Armageddon” –  more evidence for the drastic decline in insect numbers. Annals of Applied Biology, 172, 1-3.

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

Schuh, S. (2012) Archives and conservation biology. Pacific Conservation Biology, 18, 223-224.

Schuh, S., Wesche, K. & Schaefer, M. (2012a) Long-term decline in the abundance of leafhoppers and planthoppers (Auchenorrhyncha) in Central Europe protected dry grasslands. Biological Conservation, 149, 75-83.

Schuh, S., Bock, J., Krause, B., Wesche, K. & Scgaefer, M. (2012b) Long-term population trends in three grassland insect groups: a comparative analysis of 1951 and 2009. Journal of Applied Entomology, 136, 321-331.

Skórka, P., Lenda, M., Moroń, D., Kalarus, K., & Tryjanowskia, P. (2013) Factors affecting road mortality and the suitability of road verges for butterflies. Biological Conservation, 159, 148-157.

Soga, M. & Gaston, K.J. (2018) Shifting baseline syndrome: causes, consequences and implications. Frontiers in Ecology & the Environment, 16, 222-230.

 

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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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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 10 – ten more links to look at

Links to things I thought interesting

 

Why conservation needs to work around people’s values

If you ever wondered why so many plants have wort in their name.

The academic work-life balance is so wrong.  Errant Science takes a humourous look at a very serious subject.

Learn about the biology of peaches and how to cook them

Interesting commentary on a  paper about how walnuts have invaded forest ecosystems

Continuing with the food theme, how a Swedish countess introduced potatoes to the European diet

Have you ever heard a hawk moth squeak?  Now you can and they use their genitals to make the sound 🙂

If you ever wondered how beetles fold their wings, then here is the answer.  Full details about a complex subject.

Polish scientists are looking at ways of making eating insects more appetizing

Finally, William Playfair the Scottish scoundrel who invented all the graphs we love to hate

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