Category Archives: General Stuff

The Jones index of implied menace

US entomologist Justin Schmidt has carved out a place in entomological history by putting together the Schmidt pain index to measure the intensity of insect stings. These range from a score of 1 the tickle of sweat bees (Halictus species etc) to 4 the kind of pain that makes you lie down and scream (bullet ant, Paraponera clavata). The pain index is referenced throughout the internet, but this is the Natural History Museum’s take on it.

Not wanting to be outdone I’ve decided to launch the

This is the opposite of a pain index, because none of the insects has a sting. They just look threatening.

It seems obvious now, that stinging or poisonous models might be copied by harmless mimics, to trick potential predators into thinking that they were painfully dangerous, but it wasn’t until naturalist and explorer Henry Walter Bates formalized it in 1861, that the idea gained widespread understanding. It is now known the biological world over as Batesian mimicry.

The Jones index of implied menace is an irreverent unpicking of Bates’s mimicry, aligned on a scale from Woah! to Oh how cute. At menace level 4 even the hardened entomologist might take a step back and stand cautiously for a moment or two as they size up the target insect. Menace level 1 just brings a smile to your face and the thought: “What pretty colours”. Even more so than Schmidt’s pain scale, my index is subjective in the extreme. But it works for me.

4. Hornet robberfly, Asilus crabroniformis.

Damn this thing looks pure evil.

 

Arguably Britain’s most striking fly, the hornet-mimicking Asilus crabroniformis. Taken from its well-deserved place on the frontispiece in Colyer & Hammond’s (1951) Flies of the British Isles.

3. Hornet moth, Sesia apiformis.

A moth? Really? Are you sure?

The hornet moth, Sesia apiformis, is one of the clearwings, named for their narrow, transparent, unscaled and unpatterned wings which make them not at all moth-like, but very wasp-like, very wasp-like indeed.

2. Phantom hoverfly, Doros profuges.

Sleek, but with that sinister-looking narrow waist and menacingly darkened wing edges….

The ‘phantom’ hoverfly, Doros profuges. I’ve filched this as a screenshot from the excellent diptera.info website; I hope they don’t mind.

1. Ant beetle, Anthicus floralis.

Looks a bit like an ant — if you squint.

Anthicus floralis does look remarkably ant-like when it runs about at top speed on the ground. But it’s hardly a thing of nightmares.

Like Schmidt, I’m prepared to allow some latitude, breaking out from the 4-point scale, when necessary. The brightly coloured craneflies, Ctenophora, look creepy as well as being threateningly coloured, enough to score 3.5 maybe.

For some people the creepy long legs do it, for others it’s the intimidating upturned spike of a tail. But, like all craneflies, a female Ctenophora pectinicornis is completely harmless.

Most hoverflies would rank 1, although I might make an exception for Volucella zonaria, and give it a 3, if only because of its menacing size.

Even dead in the hand it looks unnerving — Britain’s largest hoverfly, Volucella zonaria.

On the other hand conopids, which are visually superb wasp mimics actually look too cuddly, so only get 2, except for Sicus ferrugineus which, with its curled can-opener tail, looks a very sinister 2.7.

The brightly coloured wasp longhorn, Rutpela maculata, scores 2 when it walks, but a waspish 3 when it flies.

The wasp longhorn, Rutpela (Strangalia) maculata is a frequent flower visitor and does that hawking bobbing flight so characteristic of wasps.

So next time you stare in wide-eyed startlement at some large buzzing bug, beetle or fly, which you first thought was a wasp, but now realize is a mimic, remember to take a moment during your stand-down relaxation to ask yourself the question: “Yes, but what Jones score did it elicit?”

Hallelujah — a beetle larva to bring me to my knees

Apparently I let out a triumphal cry and sank to my knees to greet this wonderful creature — the bizarre, secretive larva of Drilus flavescens. I’ve never seen one before, but instantly knew it from photos that other people had taunted me with. And it features on the cover of the newly published Royal Entomological Society handbook on beetle larvae. Click on the photos to see the Youtube videos we took of it rippling along the South Downs Way near Plumpton Plain just west of Lewes.

Drilus larva undulating along the South Downs Way behind Falmer, East Sussex, 11.viii.2019. Click on the picture to see my Youtube video of it rippling about.

Drilus is a snail predator. The feathery appendages are a protection against it getting mired in the snail’s copious defensive slime. Click on the picture to see another Youtube video of it galumphing along the path.

The beetle is rather local, on chalk downland in southern England. At least the male is. It looks just like a beetle — its wing cases are brown, its head and thorax are black, and its long feathery antennae are very distinctive. It flies readily and I’ve caught it in my bare hands in my parent’s garden at the foot of the South Downs in Sussex. The female, on the other hand, is a flaccid bag of eggs, lacking wings or wing-cases and weighing 50–100 times as much as a male. On 18 June 2003 I was similarly brought to my knees by this beetle when I found a mating pair walking across the footpath at High Elms, near Downe in Kent. 

Sexual dimorphism at its most extreme? At the time I thought this was likely to be the first photograph ever taken of Drilus flavescens mating.

Entomology is one of the most fascinating studies in the world. There is always something new to see, to discover, to get excited about. I thrive on what some people might call a childish enthusiasm. And it makes me smile.

Treasure. Look at that grin.

Why fossils shouldn’t really exist

I’m writing a book about ants. It’s still many months from completion. A chapter on ant evolution must mention fossils, so I thought I’d throw this suggestion into the internet maelstrom to see how it should be honed. Or binned.

MIRACLES IN STONE — WHY ARE FOSSILS SO RARE?

Recognizable ants have been around for at least 100 million years. We have exquisitely preserved fossils in amber to prove it. A quick internet search shows that ants preserved in amber are widely available from dealers. I was tempted by several in the £15–£30 price bracket. The ants were all tiny, 2–4 mm, but with low monetary value they were unlikely to be fakes. However I was not temped by the mating ‘queen and drone’ for sale from a US website at $49,500. If memory serves, this is the same item that I came across over 10 years earlier when I was researching ‘the most expensive insect’ (Jones, 2010, Extreme insects, HarperCollins), and which was then on offer for $100,000. No matter how rare such an event might be to get fossilized, this seems to be a fairly arbitrary sum, even if now knocked down by 50%.

But it at least got me thinking.

Dinosaurs have captured the popular imagination, but this las led to some completely silly and imaginary ideas about fossils. Fossils are real, but they are so rare that they do, actually, verge on the mythical. I casually wondered out loud what might be the chances of something getting fossilized. This seemed like quite a straightforward question to me, but I soon found out that nobody was willing to offer up any calculations. Taphonomists (fossil palaeontologists) openly mocked my question, claiming that ‘putting odds on it is impossible’. Having thought about it a bit more I’m tempted to agree with them. Nevertheless, having set the metaphorical ball of fiery curiosity rolling through my brain, I here offer some back-of-the-envelope calculations.

Firstly — how many ants have ever been available for fossilization? We have to start with a calculation from over half a century ago, by C.B. Williams (1960, The range and pattern of insect abundance, The American Naturalist, 94: 137-151). Extrapolating from bird counts, insect trapping surveys, log–normal biodiversity indices and world-wide species lists, he estimated 1018 insects on the planet at any given time, of which say 1% were ants; this would give us 1016. Assuming some sort of conformity with modern faunas, and allowing each ant to live 1 year, the last 100 million (108) years would therefore have produced 1016 x 108 = 1024 ant individuals having crawled on planet Earth.

Secondly — how many fossils are known? It turns out that about 750 fossil ant species are described from, say, 10,000 ant fossils. At the final count this does not seem like very much at all. 

Finally — what proportion of fossils have we humans found? Of course humans have only discovered a tiny fraction of the fossils buried in the soil. This is where the calculations and guesswork start to get a bit fanciful. For the sake of argument, I’d suggest that humans have only discovered 0.001% of ant fossils;  this is a figure I admit to having arbitrarily plucked out of the air. I dare somebody to disagree with me.

So, if 10,000 known fossils represents 0.001% of the total, that total number might be 109. This would still give the ratio of all ants to fossil ants at something like 1024 : 109  or in more conventional usage 1015 : 1. These are incomprehensibly small odds.

Given that the chance of winning the UK’s National Lottery is reportedly 4.5 x 107 : 1 (45 million to one), the chances of an ant becoming fossilized are about on a par with the same person winning the lottery two weeks running. Given that 32 million people are reputed to do the lottery each week, my increasingly tenuous grip on mathematics suggests that it might take 613, 278 years for them all to have just a single win. For someone to win twice in a row seems mathematically (and morally) untenable. For an ant to become fossilized must be equally dubious. 

It’s that unknown how-many-more-fossils-are-left-in-the-ground part of the equation that gives me most anxiety. But even if my guesstimate is out by a million-fold (even a billion-fold) the odds are still vanishingly small. Really, in any sensible world, fossils shouldn’t exist — each and every one of them is a tiny miracle of geological chance. Perhaps I was being a bit dismissive of that mating ant pair in amber.

Matchbox production line

Clearing out the parental home and I come across these almost antique collecting boxes. My dad used to make these out of matchboxes, and I did too. Quality father/son bonding time, it was.

First cut a rectangular hole in the top using a naked ‘safety’ razor blade (a Stanley knife might have been available later). Wooden matchboxes, back in the day, were easier to cut than the cardboard ones. Next glue a cover of clear cellophane over the window using that gaggingly smelly animal glue boiled up in a home-made bain-marie on the gas ring. Finally give it a neat paint job, and a number.

For at least my first decade these were our collecting boxes of choice. They were ideal for the sorts of creatures we were finding — hoverflies, greenbottles, weevils, leaf beetles, longhorns, moths, water boatmen, shieldbugs, grasshoppers and caddis flies. Anything too small could often squeeze out of a gap. Sometimes a large solitary wasp would chew a hole in the corner and escape.

I was probably 13 or 14 when I made the change to glass tubes, and although Dad did too, he often also carried a few of these old boxes in case he found a particularly large water beetle or a big fluffy moth. He’d then make an entry in his field notebook, of the painted number on the back, what he’d found, and where.

During the last 10 years of his life he hardly collected any insects, he spent all his fieldwork hours recording plants. But when I’d visit he’d pull out some of the latest things he had found and was struggling with. They were all small fry — the sort of thing you could only put into a small glass tube, not a loosely fitting matchbox. But he still kept these, along with a few similarly painted tobacco tins of uncertain provenance. Just in case.

Perspective

It’s really important to keep things in perspective. This was brought home to me, forcefully, when I was very young.

It’s not just insects, or wildlife, or even nature that fascinates me. It’s everything about the world — and the universe beyond it. I’m embarrassed to say that it’s dimmed a bit of late, but when I was a boy I was deeply interested in astronomy. I had an Airfix model of a Saturn V rocket, planetary and star charts on the wall, and a map of the moon marked with Apollo and other landings.

I had a few books too — probably something or other by Patrick Moore, a pictorial spotter’s guide to constellations, a pictorial atlas of planets, moons and galaxies, and I remember some sort of history of astronomy.

But it was an astronomy picture book I sent off for, from the back of a Weetabix packet (or it might have been Shreddies) when I was about 10, that caused all the trouble. It haunts me to this day. In it was a diagram showing the life of a typical star, from vague gas cloud to condensed solar orb of the main sequence (like our sun today) to red giant to white dwarf. It was a simple diagram, clear and to the point. It was this that got me all agitated.

Five billion years from now, having used up nearly all of its hydrogen in fusion to create helium, the sun’s mass (currently 2 x 1030 kg) will have reduced to the point where its gravity grows less, the internal pull on its gaseous structure diminishes and it starts to expand in size. As the outer layers glow hotter and redder, it will engulf the orbits of, first Mercury, then Venus, then Earth.

The Earth will be vaporized in five billion years time.

I was beside myself with despair and sat on the bed weeping and wailing my 10-year-old equivalent of “What’s the point of it? We’re all going to die.” It wasn’t so much my own death I was worried about, more the end of civilization as we know it.

My father sat down on the bed to try and console me. He probably tried to explain why it didn’t matter what would happen 5,000,000,000 years from now — further into the future than the Earth is now from its origin. Maybe he made science-fiction predictions about translocating the Earth’s population to extraterrestrial colonies, or perhaps even towing the planet off into deeper space.

I did calm down, and eventually got to sleep that night. But afterwards, each time I surreptitiously glanced at that stellar evolution chart, I had another frisson of anxiety.

So maybe that’s why I spend so much time looking at the tiny things of the world. They take my mind away from some of the larger things.

Wasps — watch this space

First proofs for Wasp are in. These are just a few samples to give a taster.

Watch this space.

 

Make way, the arachno-ambassadors are coming

NOTE: If you’re a journalist and you’ve come across this article researching false widow spiders, there’s a useful fact box at the bottom of the page that will give you all the necessary information you need.

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Five years ago I made mockery of the tabloid media for descending into the realms of garbled fantasy and blinkered ignorance. Schools were being closed because of infestations of false widow spiders and journalists the length of the country were sharpening their ill-honed wits to sell more ill-informed guff to an unwitting public hungry for sensationalist claptrap.

It’s happening again. Despite 5 years of ever-improving scientific knowledge and a resurgent interest in the natural world amongst their teachers and pupils, schools are still being closed because of fears over spiders. Urgh.

This is the cause of all the angst — Steatoda nobilis, a noble creature sadly maligned by being called a ‘false widow’ to give it the sinister connotations of the distantly related black widows. And no, it did not bite me.

It started in London.

This from the Evening Standard.

This from the BBC.

But whose fears are being pandered to? I doubt it’s the pupils. It seems the disconnect between humans and nature is not just a case of children no longer playing in the countryside, it is that adults (in this case some teachers, school governors, education department executives, parents too maybe) are falling victim to ancient prejudices and silly stereotypes, and these are being reinforced by the failings of the usual clamorous tabloid inanity. The sooner Mary Colwell manages to get a GCSE in Natural History established, the better.

Buglife were quick to make their astonishment known by publishing a response that tried to counter the “radical and unnecessary overreaction“.

This is my response, and to help get the message across I recruited the willing helpers of Ivydale Primary School in south-east London.

What’s in the jars? Why spiders of course. Everyone loves spiders.

Not all spiders are dark and sinister bundles of threat and danger. What if they were are prettily coloured as butterflies?

Colouring in the spider also gets across the subliminal message that they have eight legs, mostly eight eyes, and only teeny-tiny jaws.

At the beginning of the lesson some pupils claimed to be frightened of spiders. Well that all changed.

Next up — produce powerpoint presentations on why spiders are our friends. It wasn’t long before they were googling ‘cute spider pictures’ or ‘how many flies does a spider eat in a year?’ or ‘how many species of spider are there?’

Each spider was lovingly handled, like it was a favourite pet. Top tip: supermarket spice jars make the best containers — solid, clear, roomy, familiar.

The head teacher Helen Ingham came in to see how we were getting on. I think she was pleased that none of her pupils had been traumatized, or bitten.

And no complaints from parents, either.

So now the serious part. What did the pupils of Ivydale learn? Here are some important facts:

  1. No spiders are poisonous — they are venomous, that is how they catch their insect prey. Expansion note: Stinging nettles are not poisonous, cook them and they are delicious (taste like spinach), but they are venomous and sting by injecting venom through tiny hollow hairs on the leaves and stems.
  2. Humans are covered in an amazing substance called skin, even in children it is too thick and tough and leathery for most spiders to get their fangs into; spiders have small mouths and just cannot get their jaws open wide enough to give a nip. Expansion note: Imagine you are a spider trying to bite a human finger — it’s like you trying to take a bite out of a big leather football. Skin is also waterproof — try cleaning it with soap in the bath.
  3. Of roughly 670 different species of spider in the British Isles, only about 6 species have fangs long and strong enough to get the venom through. It feels a bit like a bee sting. Expansion note: Imagine you are a school teacher and see bees visiting flowers in the playground; do you close the school because of a dangerous threat? No, obviously not, that would be silly.
  4. Spiders are small, solitary and non-aggressive, they have soft delicate bodies and do not want to get into stand-offs or fights with humans. Expansion note: If you pick up a spider between finger and thumb it might try and fight back by biting. If you pick up a bee or wasp between finger and thumb it will sting you. If you pick me up between finger and thumb I will bite and kick. Children are more likely to be bitten by each other than by spiders.
  5. No school, office, home or indeed any building should be closed because of an ‘infestation’ of spiders. Expansion note: If you are worried about spiders ask to speak to one of Ivydale School’s pupil arachno-ambassadors, they’ll put you straight.