Category Archives: London Invertebrates

Tolerance! (And The Limits of Tolerance)

Dear Readers, it’s funny what we have tolerance for as gardeners, and what pushes us to the limit. In the front garden this year I’ve let the Green Alkanet have its head – I know it’s a thug, but it attracts more pollinators at this time of year than practically anything else. Look at this gorgeous Holly Blue butterfly, for example – they all seem to have come out in the past few days and you can often see them circling around one another in tight, dizzy circles.

Holly blue from a most peculiar angle.

The plant is not just a magnet for butterflies, though – it’s also visited by honeybees (I suspect from the hives over in our local allotments) and various hoverflies and solitary bees, including a very late female hairy-footed flower bee. The hoverfly in the photo below is, I think, a Common Hoverfly (Syrphus ribesii) – if so I’m delighted, as its larvae are ferocious feeders upon aphids, eating up to 50 a day. If the last few years are anything to go by, my two buddleia plants, which are currently looking green and healthy, will soon be dripping with honeydew from the sheer volume of greenfly, which are cheerfully picked up and moved around by the black ants that live under the patio.

So what is it that I won’t tolerate? Does anyone recognise this?

It’s our old friend Prickly Sowthistle (Sonchus asper) and London seems awash with it at the moment. This individual was growing in one of my fancy pots next to the semi-squashed catmint, and had somehow managed to achieve a height of about a metre without me noticing (well, I have been away/busy). And somehow, this was a step too far, and out it came. It seems there are limits to my acceptance of ‘wildflowers’ after all (and yet I am turning a blind eye to a few nettles in amongst the lavender and the green alkanet because I figure there’s a good chance that something will be benefitting from it).

I accept that I am prepared to accept a wider range of ‘weeds’ than most people (after all, what would I have to write about?) but I am curious. What plants will you pull out as soon as they raise their heads? What do you tolerate because you’re fond of it, in spite of its ‘weedy’ status? I am reminded of my Mum asking the gardener to mow around the patches of daisies because she loved them so much (and bless him, he always did). I suspect that we’ve all got a soft spot for something.

A Slightly Frustrating Day

The pond, complete with bog bean…

Dear Readers, since 7 a.m. this morning (and yes, it is Saturday as I write) I have been hunched like a vulture over my second Biology of Survival assignment for my Open University degree. What a palaver! I am nearly there, but I am very frustrated that my cyber-rats aren’t doing what I expected them to do. And you can tell me all you like that a failed experiment provides just as much interesting data as one that comes up with the answers that you’re expecting, but it just isn’t as satisfying as when everything falls into place. I suspect that the problem is my sample size – we only have five ‘rats’, and one of mine is the smallest rat I’ve ever seen, even in cyberspace – he or she is barely mouse-sized and I suspect that that is skewing my results. Oh well. At least I’ve nearly caught up now, after not being well before Christmas.

And in other news, I heard the first tentative croaking of a frog in the pond this afternoon, so I stood there in the rain hoping I could see him and capture his portrait. Alas, he was too shy, not a problem that he and the rest of his little friends will have in a few days time when the ladeez turn up and the testosterone gets working. But for now, it was just the demurest of sounds, almost as if Mr Frog was clearing his throat, or trying out his voice after a long winter spent in the mud. I wish him luck, especially as I’ve noticed several cats gazing intently into the water over the past few days. Cats do love to play ‘whackamole’ with the frogs, though they seldom eat them (presumably they’ve learned that frog skin has a rather nasty toxin in it). Let’s see how things shape up over next week – I actually have a couple of days off, so I can keep an eye open.

Oh, and there seems to be a fly hatching from the water. Let’s hope the frog doesn’t spot it.

Wednesday Weed – Groundsel Revisited

South London Groundsel (Senecio vulgaris)

Dear Readers, when I was on my walk from Beckenham to Crystal Palace last week I was impressed by the sheer volume of groundsel. I have seen it growing weedily from cracks in the pavement in North London, but it seems to be at its happiest growing amongst the plantain and dandelions on a patch of proper rough ground.

This is a plant that has been with us ever since we first colonised the UK, and I love its old-fashioned quality, although as each plant can produce up to 1700 seeds three times per year, it is not so popular in other parts of the world. Furthermore, after drying and cold storage for three years the plant still achieved a germination rate of 87%, and it should be very proud of itself.  However, groundsel is not thought to be particularly harmful to native plants or to crops, unless you happen to be a mint farmer in Washington State. Who knew that there were mint farmers? I learn something every day on this blog. My Nan used to say that mint ‘goes seven times to the devil and once to you’, but in my experience if mint is happy you might as well give up all hope of growing anything else in that particular spot.

There is some debate about whether groundsel is toxic, either to humans or to animals, but it is clear that it was used as a purge, something that was often the case with plants that were mildly poisonous. For your delectation I present this tale collected by Roy Vickery who, along with Richard Mabey are my go-to people for the folklore and historical uses of UK plants. The description is rather graphic and the language is rather salty, so you might want to scroll past if you’re of a delicate disposition.

Mr Joby House, who used to be at Hewood, told us that, for constipation, you boiled groundsel and lard and take that and you will shit through the eye of a needle. His sister Lucy had constipation so bad that when the doctor called in the morning he said Lucy would be dead by 5 o’clock. Mrs. House went to the gypsies (Mrs. Penfold)…and she told her how to cure her. The doctor came late in the day, and Lucy was running around; there was shit everywhere. The doctor had brought Lucy’s death certificate, but he was so mad he tore it up and put it in the fire’ (From The Oxford Dictionary of Plant Lore (Roy Vickery 1995))

As I mention in my original piece, groundsel is munched upon by many, many caterpillars, so here is a poem by Julian Bishop. I love the idea of the caterpillar’s world view being reconfigured. See what you think.

CATERPILLAR by Julian Bishop

The weeks play out in peaks and troughs
charted by the parabola of his back –
he meanders from one room to another,
all wreathed in the same leafy wallpaper.

Every morsel of groundsel is a Groundhog Day –
there’s no furlough for a hungry caterpillar.
He knows an airborne killer hovers over
his world of constant foraging, a beak

swooping out from behind the green curtain.
Nonchalant about the hair-raising danger,
other caterpillars give him sage advice:
Bruv, it’ll get you one way or another. 

One day his restricted life will be lifted
by the gods gifting him a pair of wings.
From the cockpit of his modified body,
he will gaze down goggle-eyed on a land

reconfigured, where for a few precious weeks
heaven was a place of herbal teas, perpetual eating,
garden meals the boundaries of liberation.
Where will his new-found freedom take him?

And now, back to 2014 when I wrote this original piece.

Groundsel (Senecio vulgaris)

Groundsel (Senecio vulgaris) (and is that a roach or a dog-end in the top right of the picture, I wonder?)

What a non-descript, retiring little plant Groundsel is. Slightly droopy (especially in the hot weather we’re having in London at the moment), it lurks in the toughest corners of the urban environment, at the bottom of walls and in the smallest of cracks. But this is one tough plant. The Groundsel photographed here is growing in a spot which was blitzed with weed-killer about six weeks ago (much to my annoyance). Dog pee, blazing sun, tiny amounts of soil and huge amounts of pollution daunt it not. The name ‘Groundsel’ comes from the Old English for ‘Ground Swallower’, and it has advanced to all four corners of the globe, probably because its seeds have been mixed in with food crops.

The light, hairy seeds of the Groundsel can travel a long way....

The light, hairy seeds of the Groundsel can travel a long way….

Richard Mabey points out that the ‘Senecio’ part of the Latin name for Groundsel comes from the word for ‘Old Man’. With its seeds attached, the seedhead looks rather like Einstein’s hairdo, but when they are all gone, it looks like the (somewhat dimpled) head of a bald man.

I remember feeding my budgie on Groundsel and Chickweed, and it is said to  persuade rabbits to feed when nothing else works. In ‘Watership Down’ by Richard Adams, one of the wisest rabbits was named Groundsel, which is maybe a nod to the animals’ dietary preferences.  The seeds are also taken by sparrows and finches – I tend to forget that, before birdtables came along, wild birds did perfectly well finding food for themselves. Indeed, once upon a time a certain proportion of ‘weeds’ such as Groundsel were happily tolerated in our fields, and so there was plenty for birds to eat in rural areas. These days, the fields are less biodiverse than our gardens, and so the birds that are left come to us. For an agricultural approach to groundsel (otherwise known as ‘blasting it off the planet), have a look at the approach taken by Dow AgroSciences here, and weep.

Groundsel Blog 2Groundsel is a favourite food of Cinnabar and Flame-Shouldered Moths, and the Ragwort Plume Moth. In fact, the plants of the Groundsel family (which includes the Oxford Ragwort and various types of Fleabane) support an extraordinary number of butterflies and moths, and a partial list is included here

Cinnabar Moth Caterpillar By joost j. bakker [CC-BY-2.0 (], via Wikimedia Commons

Cinnabar Moth Caterpillar By joost j. bakker [CC-BY-2.0 (], via Wikimedia Commons

Flame-shoulder moth By picture taken by Olaf Leillinger (Own work) [CC-BY-SA-2.5 ( or GFDL (], via Wikimedia Commons

Flame-shoulder moth By picture taken by Olaf Leillinger (Own work) [CC-BY-SA-2.5 ( or GFDL (], via Wikimedia Commons

So, the main habitats of this ancient weed are now our city streets and brownfield sites, our railway sidings and wastelands. This is why these sites can be so important, particularly for insects. At least on a derelict site, there are unlikely to be regular applications of insecticides and herbicides. Our greatest biodiversity is not found in ‘the countryside’ anymore, but in those marginal areas that have not (yet) been developed. It’s important to remember that a Cinnabar Moth caterpillar doesn’t care what an area looks like, just that it has enough to eat. For some more information about Brownfield sites, and why they are important to insects , I can recommend this article from Buglife, a charity worthy of support by anyone who cares about our invertebrate neighbours.

Groundsel blog 3





After the Rain at Barnwood

Dear Readers, it’s always interesting to see what has and hasn’t thrived during the drought of the past few months. At the Barnwood Community Orchard, some of the trees and fruiting shrubs are still doing very nicely, even the recently planted ones (largely due, I suspect, to the care and attention given to them by the volunteers at the site. On the other hand some plants, such as the hazel to the left of the photo, are covered in crisp brown leaves and look very sorry for themselves. I wouldn’t give up hope just yet, though – native shrubs such as this can be very resilient, and it’s more  than possible that it will resurrect itself after the recent rains.

Many of the other plants are looking very healthy. This guelder rose (Viburnum opulus) is full of berries. What good value this plant is, with its white flowers in spring, its red fruit in late summer and its fine golden colour in the autumn. It’s also one of the national symbols of Ukraine, and so it couldn’t be more appropriate.

I love the way that small fruit trees look when they have a few pears or apples on them – they often look almost overwhelmed by what they’ve produced. This little apple is called ‘Ellison’s Orange’, and is apparently a cross between Cox’s Orange Pippin and a variety called Cellini. It’s said to develop an aniseed flavour in storage (unlikely to be a problem this year as I imagine these apples will get munched up very quickly), and to be more disease-resistant, and juicier, than Cox’s. However, it is said to be prone to apple canker (a fungal disease of apple trees that attacks the bark) and therefore requires good drainage. The variety was first seen in 1905, and is believed to have been developed by C.C. Ellison, a Lincolnshire priest who clearly had a fondness for apples.

Ellison’s Orange

Now, as usual I was keeping my eyes open for invertebrates, and I found a very fine spider on some dried-up teasel. It seemed to be feeding on a shieldbug nymph, and at first I thought it was something exotic – look at that lovely lacy pattern on the abdomen.

But no, this our old friend the Noble Spider (Steatoda nobilis) – I normally have a couple of these living in my sash windows in the kitchen. The good folk at the UK Spider Identification Group on Facebook, along with many other people, have been trying to rehabilitate this rather fine spider by changing its common name from ‘Noble False Widow Spider’, which was rather playing into the sensationalist headlines of the tabloid press. Schools have been shut down because of this spider, people have accidentally burnt down their houses by trying to get rid of them with flame throwers and they have been blamed for people losing their limbs.

It’s true that they can bite, but only if provoked or trapped next to skin, and in most cases the result is no worse than a wasp sting. There have been cases of infections after ‘spider bites’, but this would be the case with any puncture wound, and in none of the cases has the initial cause been proven. In short, if you leave these guys alone (the male is more prone to bite, but only because he wanders further in search of a mate, and is therefore more likely to come into contact with people), and just admire them from a safe distance everybody will be ok. And just think of all the midges and mosquitoes and houseflies that they consume! Spiders are some of my favourite house guests, and I don’t even need to change the bed.


And finally, here is a Barnwood-related puzzle. A moth trap has been run in Barnwood for several months, but when Leo, custodian of all things Barnwood-related, opened the trap to inspect it a few days ago, he found that all  the Jersey Tiger moths had been beheaded and partially eaten. What could be causing this crime? We did wonder if the culprit was the mosquito who was found alongside the ‘body’, but only briefly.

Jersey Tiger with completely innocent mosquito

The murderer is likely to be a wasp – they are voracious hunters, and I believe that they can learn about food sources, and how to exploit them. They may even communicate with one another to reveal where food is. Leo is currently considering how to manage this new problem – he notes down the moths that he finds and releases them safely, but has never had dead moths before. It will be interesting to see what happens next.


A Very Fine Bug

Dear Readers, one of the advantages of being a lover of invertebrates is that, during this hot weather, all manner of creatures have flown into the house. The house flies and green bottles are something of a nuisance, but then there are animals like this tiny bug with its very impressive red and black patterning. I rather think that it looks like an impressive African mask.

This is a Cinnamon bug, or Black and Red Squash Bug (Corizus hyoscyami), also known as a ‘scentless plant bug’ to distinguish it from the more commonly-seen stink or shield bugs. It was a very relaxed creature, allowing me to gently prod it into a glass once I’d taken its portrait, and ambling onto a plant once I’d taken it into the garden. None of that manic buzzing that many insects indulge in when trapped! Historically this insect was found in coastal areas but (and here I feel a bit like a stuck record) it is moving north as our climate changes. It also favours dry environments, which might also help to explain the increase in its range.

The Cinnamon bug belongs to the Rhopalid family, all of which are plant-feeders, though none are thought to be pests. It overwinters as an adult, and new bugs emerge from August to October. What I haven’t found is any convincing reason for the creature to be named after cinnamon. One theory is that it emits a spicy smell if handled, but I’m having trouble squaring that with it belonging to the scentless bug family. Cinnamon comes from the inner bark of various trees, so I’m thinking that this little chap doesn’t have the jaws necessary to feast on it. Who knows? If you have any ideas, let me know. I’m just really impressed with his red and black livery, and easy-going nature. Who knows what other insects will fly in? I shall keep you posted.

What Does Climate Change Mean For Bumblebees?

Dear Readers, there has been quite a lot of research on the subject of bumblebees and climate change. After all, one look at these large, ‘furry’ insects is enough for me to worry about them buzzing about wearing the equivalent of a mink coat. They are, in fact, adapted for tundra conditions – their large size relative to pollinators like honeybees means that they lose heat more slowly than smaller insects (remember that surface area to volume ratio thing that many of us learned in O-Level biology). The ‘fur’ (actually outgrowths of the abdomen and thorax called setae) helps to insulate the bee against cold temperatures, and the bees also have very large flight muscles, which they can warm up by vibrating them – bumblebees are often the only pollinators in flight on a cold morning, and queens can sometimes be seen foraging as early as January in the UK. They also, unusually for insects, can generate their own body heat – they use enzymes that can break down the sugars found in nectar to help them to warm up. The queen in the photo below was spotted on my birthday, 20th January, earlier this year.

Bumblebees generally have one generation per year. In the spring, a queen bumblebee comes out of hibernation, and sets off to find a spot for her nest – you will often see large bumblebees flying low over the grass as if looking for something. A mousehole, dense ivy or a gap under a shed are all desirable spots. Once in her nest, the queen lays her first few eggs, and feeds them all by herself until they hatch as workers and are able to forage themselves. Eventually, there are enough workers for the queen to concentrate on laying her eggs. The colony will comprise less than 1000 individuals, and towards the end of summer the queen will start to lay eggs that will develop into fertile queens, and males. These will leave the nest and mate. The queens, already pregnant, will find a space to hibernate, and the males, the original queen and the rest of the workers will die.

So, bumblebees are basically big and hairy in order to survive in cold climates. How, then, are they doing in the heat?

It’s true that there are bumblebees in tropical and sub-tropical habitats, but these are mostly found at high altitude, where it’s colder, and  they tend to be smaller, meaning that they can lose heat more easily. However, the bumblebee species found in southern Europe and the southern USA are thought to be pretty much at the edge of their range, and are expected to disappear as the summers get hotter and drier, and the winters milder.

For bumblebees in the UK the effects of climate change will depend on the rapidity of change, and intensity of individual events. At over 37 degrees Centigrade, bumblebees forage much less effectively. Queens have something called heat stress proteins, which can protect them against extremes of temperature while they’re hibernating, but workers and males do not have these proteins, as far as we can tell. Bumblebees are also prone to water-stress (desiccation) – one thing that I did during the extreme heat of the past few days/weeks was put out a dish almost full of gravel, and then topped up with water so that insects could land safely and drink.

Bumblebees are tough, adaptable creatures ( I often think of them as the Einsteins of the insect world) and they have a number of behaviours that help during extreme weather conditions. Bumblebee nests are tiny compared to those of honeybees (under a thousand individuals as opposed to tens of thousands), but the workers will club together to  vibrate their wings to try to keep the temperature between 28 and 32 degrees Centigrade. They will also change their foraging behaviour during hot spells, going out in the early morning and later in the day to avoid the heat of midday. Bumblebees also seem to be choosing more isolated, cooler spots in order to make their nests.

However, finding those cooler, more isolated spots is clearly becoming more problematic due to a combination of our habit of paving over our gardens,  using fake grass ( a particular bugbear of mine), agricultural intensification, deforestation and urbanisation. Some bees are migrating to try to find better habitat, and others are seeking spots at higher altitudes, as are many other animals and plants that are adapted to colder conditions. One important  question is ‘what happens when the temperature in mountainous habitats also rises?’

So, how are the bees coping so far? One interesting adaptation seems to be that some buff-tailed bumblebee colonies are surviving through the winter in the UK – presumably people are planting enough winter-flowering honeysuckle and mahonia to enable the colony to survive on iron rations until the spring comes. This may be preferable in some circumstances to a situation where a hibernating queen keeps waking up during the winter and hence burns through the fat reserves that would normally be used to produce her first few eggs. However, a non-hibernating queen will also produce fewer workers, so it may be a trade-off against different conditions.

Climate change is also affecting the delicate balance between the different stages of the bumblebee life cycle and the emergence of the flowers that they rely on – it’s clear that plants are flowering earlier than they used to, which may favour colonies that keep going through the winter, and fortunately many species of bumblebee in the UK can feed on a variety of different kinds of plants, so they will not be as affected as some of the bee species which are more specific in their requirements.

The bottom line is that bumblebees probably can adapt to the higher temperatures of climate change, but only up to a point, and only if there is enough genetic diversity for those adaptive factors to be present in the community of bees. Like animals trapped on islands, bumblebees are increasingly isolated from one another, trapped in small areas of botanical plenty while surrounded by deserts of concrete and agricultural monoculture. The idea of ‘pollinator pathways’, whereby bees of all kinds can forage more widely and can meet and mate with bees that they wouldn’t otherwise meet, is an important one, and it depends on everything from the planting of bee-friendly street trees to putting a pot of lavender or rosemary on the balcony. Will it be enough? Only time will tell.

Common carder bumblebee on bittersweet

This piece is largely taken from ‘Bumblebee resilience to climate change, through plastic and adaptive responses’ by Maebe et al, published in June 2021. The abstract is available here though it looks as if you might need access to a university library (or $15) to read the whole thing. Shout if there’s anything that you want me to look at in more detail – this is a meaty piece of work, and I have tried to precis it. 

I also found this article interesting, especially on the subject of  bee body size and mountainous habitats. 

An Old Friend

Fencepost jumping spider (Marpissa muscosa)

Dear Readers, I was talking to my friend J about tattoos at lunch today. At the age of 60 she is planning on getting one in the shape of a swift, and so the conversation turned to what I would have, in the event that I decide to be artistically punctured with lots of small needles.

“A jumping spider”, I said, without any hesitation. And therein hangs a tale.

When I was six or seven, I was out in our tiny garden as usual. I had spotted a tiny creature on the concrete slab that housed the giant post for our washing line, and I had noticed that it was acting very strangely, so I lay on my stomach (in my best party dress as we were supposed to be going out) and realised that the animal was a spider about the size of my fingernail. A few inches away on the slab, a house fly was cleaning its eyes with its hairy front legs, rotating its whole head by about 240 degrees like they do. The spider was prowling ever closer, using the lumps and bumps in the surface of the concrete as cover. Then, it paddled its legs, tensed itself and leapt through the air onto the back of the fly.

And in that moment was Bugwoman born. Because I don’t think I had ever seen anything quite so thrilling or so unexpected, and it opened my eyes to a whole world of astonishment and good old-fashioned awe.

Back to the present day, and I was getting some cushions for the chairs in the garden out of the cupboard when I noticed this little chap. And I am quite sure he was a chap because those ‘boxing gloves’ are pedipalps, which he uses to insert his sperm into a female spider if she is willing to accept him, though my lovely friends at the British Spiders Facebook Page tell me that this is just a young male, as in adults those pedipalps would be more formed, and his stripes would be more defined.

Jumping spiders don’t use webs or any of that namby-pamby stuff – though they will anchor themselves to the ground with a silk line before they spring, just in case the jump fails. They are hunters through and through, and so they have those astonishingly large eyes at the front of their faces which help them to judge distance. The slightly smaller eyes which are further back are used to detect motion.

Most invertebrates, including most spiders, seem broadly oblivious to human presence, moving away when they sense a shadow or hear the vibration of footsteps, but jumping spiders actually look at you. They may even cock their heads like attentive dogs. To me, they are utterly adorable, and much easier to love than some of the bigger, hairier, danglier spiders that you might encounter in a shed. You are not supposed to have favourites, but I confess that these creatures fill me with a warm glow. Here’s a short film of this little chap.

Jumping spiders will also chase a laser pointer in much the same way as cats do. They probably have tetrachromic colour vision (which is better than our colour vision) and they also have high-sensitivity to ultraviolet light. They live in a colourful world, for sure, and in experiments they’ve been shown to be able to learn, remember and recognise particular colours.

Jumping spider chases laser pointer

Although this particular jumping spider is not very brightly coloured, the family to which he belongs (the Salticidae) are extremely varied, with over 6000 species, including the peacock spiders. You may well have come across them before, but if not, have a look at this extraordinary BBC film . Such tiny creatures, with such complex lives! It just reminds me of how little we actually know about the animals and plants that we share the planet with.

And so, I persuaded the jumping spider onto the fencepost for which he is named. Hopefully he’ll find a female jumping spider. At the very least, he’ll be able to find some insects to munch on. Good luck, little chap.

A Spring Walk in St Pancras and Islington Cemetery

Dear Readers, three weeks after the onset of my Covid I’m finally feeling like myself again, and so it was such a joy to head out to St Pancras and Islington Cemetery to take in the glory of the Lesser Celandine. Just look at them! Could they be any more joyful, I ask myself.

And if you watch closely, you can see them being appreciated by a whole mass of bees and tiny pollinators.

The primroses are out in force too.

I heard the buzzards mewing, and saw one being hotly pursued by the usual gang of crows. And, for your delectation, here is a sparrowhawk’s backside, shortly before she exited stage left, also pursued by crows. Note those distinctive bars on the stomach.

Blackcaps were singing their heads off, as was this chaffinch, who was making a most uncharacteristic volume of sound.

And the blackthorn is in flower.

I have mentioned before that the lesser celandine was Wordsworth’s favourite flower, but I’d never read the poem that he composed to it. I had expected some cheery paean to the first flower of spring but, as so often with Wordsworth it’s rather more thoughtful than that. So here, for your delectation, is Wordworth’s Lesser Celandine. See what you think.

The Lesser Celandine

There is a Flower, the Lesser Celandine,
That shrinks, like many more, from cold and rain;
And, the first moment that the sun may shine,
Bright as the sun himself, ’tis out again!

When hailstones have been falling, swarm on swarm,
Or blasts the green field and the trees distressed,
Oft have I seen it muffled up from harm,
In close self-shelter, like a Thing at rest.

But lately, one rough day, this Flower I passed,
And recognized it, though an altered form,
Now standing forth an offering to the blast,
And buffeted at will by rain and storm.

I stopped, and said, with inly-muttered voice,
“It doth not love the shower, nor seek the cold:
This neither is its courage nor its choice,
But its necessity in being old.

“The sunshine may not cheer it, nor the dew;
It cannot help itself in its decay;
Stiff in its members, withered, changed of hue.”
And, in my spleen, I smiled that it was grey.

To be a Prodigal’s Favourite -then, worse truth,
A Miser’s Pensioner -behold our lot!
O Man, that from thy fair and shining youth
Age might but take the things Youth needed not!

William Wordsworth (1770-1850)

The Mosquitoes of the London Underground

Photo One by Walkabout12 - Own work, CC BY-SA 3.0, Walkabout12 - Own work, CC BY-SA 3.0,

The London Underground Mosquito (Culex pipiens f. molestus)(Photo One)

Dear Readers, I was much taken by an article in New Scientist about the evolution of urban species by Rob Dunn this week, and in particular his thoughts about the infamous London Underground mosquito. During the Second World War, unfortunate civilians who spent nights on the platforms of Underground stations to avoid the Blitz complained about being bitten unmercifully, but it’s only recently that genetic technology has advanced to a point where we can really work out what’s going on.

Photo Two by By US Govt - This media is available in the holdings of the National Archives and Records Administration, cataloged under the National Archives Identifier (NAID) 195768., Public Domain,

Sheltering in the Underground (Photo Two)

The original LU Mosquito came from the Fertile Crescent in the Middle East and lived above ground. These insects are active only during the warmer months, require a meal of blood before they can reproduce, and feed mainly on the blood of birds. However, as the mosquito spread north into colder climes, it survived by living in cities, particularly their underground regions such as sewers. The insect evolved new genetic characteristics, such as odour recognition, digestion and immunity, that would be useful in environments rich in organic waste.

However, it wasn’t just the genes that changed, behaviour did too. Both the underground and the above-ground mosquitoes are thought to be the same species, but the underground ones are active all year round, can reproduce without a blood meal, and prefer to feed on mammals: rats and mice in particular, but humans where they can find them. The underground mosquitoes are isolated from other mosquitoes, and their habitat can be compared to an island, as Dunn points out: the mosquitoes cannot disperse, and so they become more and more specialised. Cities such as Paris, Minsk, Tokyo and New York all have their own ‘Underground Mosquitoes’.

However, the isolation can have another, even more extreme, effect – it’s been shown that where LU Mosquito populations are isolated within the Underground network, they can start to become genetically distinct from one another. So, it was found that the mosquitoes found on the Victoria Line were different from those found on the Bakerloo Line. It’s quite possible that every underground line could have its own mosquito, though I suspect that lines with a larger proportion of stations which are above ground might be less distinct, because their mosquitoes can actually disperse and interbreed.

For us, though, as humans, it means that the old Petula Clark song ‘Don’t Sleep in the Subway’ has never been better advice.



The Secret Life of Flies by Erica McAlister

Dear Readers, this isn’t exactly a book review (yet) because I am only up to page 57 of this rather splendid book. However, it is so full of interesting factoids that I wanted to share a few with you, even though I am in the middle of year end and things are a bit on the frantic side (understatement). So, please forgive me for a few quick bullet points. There are more fly-related things to be said in the future, I’m sure.

First up, McAlister estimates that there are 17 million flies for every single human being currently walking about on the planet. They are a hugely diverse family, from craneflies and hoverflies to bluebottles and horseflies. But, as she puts it ‘The question you still want answering is: what have all those flies ever done for us?’

The obvious first answer is that we would be up to our ears and above in waste if it wasn’t for flies, but flies are extremely undervalued as pollinators. For example, there is only one group of tiny flies that can pollinate Theobroma cacao, otherwise known as the chocolate plant. These are known in the Caribbean as No See Ums, and I remember my Dad talking about how badly some members of this family of midges could bite. The chocolate midge (Forcipomyia sp.) manages to pollinate the flowers of the chocolate plant, but it is a very particular little creature, preferring damp, shady woodlands and moist soil or a pond to raise their youngsters. The cutting down  of forests to plant larger and larger chocolate plantations is, ironically, destroying the habitat preferred by the crop’s only pollinator. Could this be the end of the Curly Wurly? Only time will tell.

A chocolate midge (Forcipomyia sp.) (Photo by© Christophe Quintin Via Flickr (CC BY-NC 2.0)

Like many pollinators. flies and flowering plants have evolved alongside one another, and this has led to some most intriguing designs, none more so than that of Moegistrorhyncus longirostris, a fly which has a proboscis eight times longer than its body. If a human had a tongue of equal ratio, it would be over six metres long. Why the long tongue? Well, eight species of plants on the Cape in South Africa can only be pollinated by this fly or one that’s closely related, because they have such long tubes that only the longest-tongued can reach their pollen.

Just the kind of flower that longirostris feeds on…

And so I am very much enjoying this book, as you would expect from someone with a name like Bugwoman (though flies are not bugs in the technical sense of course). I am sure there will be more highlights later!