Category Archives: London Invertebrates

The Shell of the Snail

Garden snail (Cornus aspersum)

Dear Readers, I was planning to do the Big Butterfly Count this morning, but when I stepped out of the front door it became apparent that any self-respecting butterfly would be hiding under a substantial leaf to keep dry. However, half a dozen garden snails (Cornus aspersum) were gently gliding around on the wet stones, and so I sat down on the front step to watch them. I was much taken by the delicate tracery of burgundy-brown and caramel on the shell of each individual, the colours enhanced by the drizzle.  What, I wondered, were the advantages and disadvantages of having a shell (after all, slugs manage without one)? Why did the shells seem to curl in the same direction on every snail in the garden? And does the shell tell us anything about the life of the individual snail? I reach for my New Naturalist ‘Slugs and Snails’ by Robert Cameron to see if he has any answers, and several hours later, I emerge, amazed.

The shell of snail performs two main functions: it protects its owner against predation and it acts as a shield against drying out. On the downside, however, a shell requires energy to build, and energy to transport. Slugs and snails are the only molluscs who don’t live in water: a water snail doesn’t have to contend with gravity in the way that a land snail does, because the liquid helps to support it. So, we have to assume that the costs of having a shell are offset by the value of not being eaten quite so regularly, and the value of not drying to a frazzle every time there’s a heatwave.

The garden snail comes originally from the Mediterranean, and there is little doubt that it was brought to the UK (and lots of other places) by the Romans, who enjoyed eating them. The climate of the snail’s native range would historically have been much hotter and drier than Northern Europe (though all bets are off with climate change), which may explain the robust shell, especially when compared to our smaller and more delicate native snails. Traditionally, the garden snail was a creature of the warmer parts of the UK because it couldn’t survive the harsher winters ‘oop north’. Watch this space, however.

The vast majority of garden snails have what is known as ‘dextral chirality’. This means that the mouth of the shell is on the right when viewed from above, and the ‘coil’ of the shell runs clockwise if viewed from the centre. The most important organs of the snail are within the shell, and they are in torsion: if the shell is ‘dextral’, the lung, stomach etc will be twisted in the opposite direction. Chirality is inherited from the mother snail, and in most species, including the garden snail, any individual unfortunate to be born with the opposite ‘twist’ will be unable to mate, owing to the way that these hermaphrodite creatures need to ‘line up’ in order to shoot one another with their ‘love darts’. The sex life of the garden snail probably needs a blogpost all to itself.

Incidentally, snails can do something directly that most animals have to rely upon microorganisms to achieve: they seem to manufacture the enzyme cellulase, which digests the fibrous cellulose that makes up the structure of plant cells. And, while we’re on the subject of eating, the garden snail is one of the few mollusc species in the UK that eats some live plant material (most of the others are detritivores and munch up dead and rotting leaves). Young snails appear to have a particular taste for new growth. However, Robert Cameron does point out that the damage done by garden snails is a tiny proportion of the damage done by the field slug (Deroceras reticulatum) so we can probably cut them a little slack.

The shell of a snail starts with a layer called the periostracum. This is the shiny, tortoiseshell-like ‘stuff’ that I was admiring earlier. It is made of proteins which resemble those that make our fingernails. It is, however, relatively delicate, and all that creeping under stones and rubbing up against flowerpots will soon remove it. Elderly snails can look rather bleached and dull, unlike those polished youngsters that are hanging about under my buddleia. Apparently garden snails who live on sand dunes are literally ‘sand blasted’.

The strength of the shell, however, comes from the lamellar layer, which is formed from several layers of calcium carbonate, laid in opposite directions much like the alignment of the layers in plywood. Calcium carbonate is not as ‘expensive’ for the animal to deposit as protein: Cameron points out that if 5% of the shell is made of protein, that has taken about 50% of the energy to make the whole shell. Unfortunately for the snail, calcium can be difficult to find:the snail eats soil in order to get the materials that it needs, and snails living on limestone have thicker shells than those living on acid soils. Snails might also been seen eating rocks, bones or even the shells of other snails in order to top up their calcium – I distinctly remember that I once saw the skeleton of a dead sheep that was absolutely covered in snails, and now I know why. There may be no snails at all in the most acidic environments, such as heather moors or sphagnum moss, but of course there will be plenty of slugs who don’t have to worry about such things.

Once the snail has reached adulthood, it may use the calcium carbonate from its shell for other things, such as the shells of its eggs, which can be relatively hard in some species. 

One of the saddest sounds of a wet day is the muted crunchy ‘pop’ of a snail that’s been accidentally trodden upon. It’s clear that snails are not impregnable in spite of all that effort, but I was cheered to hear that, in the presence of sufficient materials, a snail can regenerate its shell, provided the damage is not too great. Indeed, you can sometimes spot a snail bearing a tatty, misshapen shell which looks as if it was stuck together with a glue stick. Ladies and gentlemen, what you see before you is a battered molluscan warrior, so respect is due. But wait! I just discovered this article which tells the worried pet owner how to repair the shells of any injured domesticated snails. Truly, the internet is an endless cornucopia of wonders.

The main advantage of a snail shell, however, seems to me to be the protection that it provides against drying out. It’s been estimated that a garden snail loses 8% of its body weight per hour while crawling around, which explains the huge number of snails that I find hiding in the overhanging lips of my garden containers when the weather gets hot. Snail shells are pretty much impermeable, and many snails can seal themselves up completely to wait for happier, damper times.

Incidentally, research across Europe has shown a clear correlation between the proportion of slugs to snails and the dampness of the climate: in Cyprus only 9% of land molluscs are slugs, whereas in lucky old Ireland it’s 31% (thanks again to Robert Cameron Fig 62 page 99). The benefit of having a shell, especially in hot dry climates,  appears to be largely about keeping the fluid levels up so that the creature can survive, rather than protection against predators. When the climate is coolish and dampish, slug diversity and numbers increase.

Garden snail (Cornus aspersa)

I have always had a soft spot for snails.  I love the way that their eye-stalks extend and contract independently, and I love the way that they ooze gracefully across the patio. I know that they can be a pest in the garden, but I suspect that they also do a fair bit of cleaning up. And on a wet night I will sometimes look up from my book to see a snail climbing up the window, silhouetted by the street light and looking for all the world like some kind of molluscan angel, ascending to heaven. The author and poet Munia Khan wrote

“The intriguing placidity from the slothful pace of a snail is truly very peaceful. Our world is in need of this calmness to pacify itself”

I couldn’t agree more.

 

 

 

 

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A Patch of ‘Water Weeds’

Where has the pond gone?

Dear Readers, during my sojourn in Austria the water plants have grown up with much enthusiasm.  Alongside the meadowsweet that I wrote about last week, there is hemp agrimony, purple loosestrife, and a patch of greater willowherb. The whole area is literally buzzing: it’s in one of the few constantly sunny areas in my north-facing garden, and, inspired by a wonderful Country Diary by Mark Cocker in the Guardian this week, I decided to ‘hang out’ for a bit and see what I could spot.

First things first. Most of the butterflies in this year have been of the white or blue species, so a flash of orange was a delight. The hemp agrimony seems to be a favourite with all winged creatures, who sink into those raggedy flowerheads in a kind of ecstasy. I had to wait a few minutes for the butterfly to open her wings, though the underside has a subtle beauty of its own.

Waiting….

And then the sun came out, and I was rewarded.

Gatekeeper (Pyronia tithonus)

Once the wings are open, it reveals those double eye-spots, which tell me that this is a gatekeeper (or hedge brown). I can tell this is a female because the male has a dark band across his forewings. The photo doesn’t do justice to the caramel colour of those wings. Gatekeepers are one of the latest flying of the butterflies, with new broods taking to the air from late June to the end of August.

Photo One by By Charles J Sharp - Own work, CC BY-SA 4.0, https://commons.wikimedia.org/w/index.php?curid=42061149

Male Gatekeeper (Photo One)

If you wanted a reason for not mowing the lawn, the caterpillars of this species would provide one. The female drops her eggs among grasses such as cock’s foot, timothy and common couch, and the caterpillars feed at night, pupating in the dried vegetation and emerging during the following year. Your grass could also support the caterpillars of speckled wood, ringlet, wall and meadow brown, small skipper and brown argus. I gave up my lawn to replace it with a pond, but I notice that grass is creeping back, nonetheless.

Photo Two By foxypar4 on Flickr - Flickr, CC BY 2.0, https://commons.wikimedia.org/w/index.php?curid=6312839

Cock’s foot grass (Dactylis glomerata) (Photo Two)

Timothy grass (Phleum pratense) (Public Domain)

The bumblebees also like the hemp agrimony, but seem to marginally prefer the purple loosestrife, and the dark red buddleia that has just come into blossom. I should point out that the latter is meant to be a dwarf variety, but is already six feet tall.

A very smart white-tailed bumblebee (Bombus lucorum)

How to tell a white-tailed bumblebee (Bombus lucorum) from a buff-tailed bumblebee (Bombus terrestris)? It’s not quite as easy as it sounds, because the ‘buff-tail’ of the latter is often white. In my book ‘Garden Wildlife’ by Richard Lewington (which has the most wonderful illustrations), the white-tailed bumblebee is described as having ‘clean’ yellow banding. whilst the buff-tail is said to have ‘dirty’ yellow banding.The Bumblebee Conservation Trust have a very useful website containing identification charts for all the common British species, and you can find it here.

Both are extremely common, the queens of both species appear as early as February on a warm winter day, and both are ‘nectar-robbers’, with short tongues that make it difficult for them to access plants with longer corolla. As a result, bumblebees of both species will cut a tiny hole in the base of flowers such as penstemon and salvia, and drink the nectar without doing any pollination.

It really comes as no surprise to me that bumblebees have learned to circumvent the carefully-evolved defences of flowering plants. I always think of them as the Einsteins of the insect world, and recent research has proved me right (though who knows what might be found if other insects were so closely observed). Bumblebees have solved the ‘travelling salesman’ problem, calculating the most efficient route between plants to maximise the amount of nectar collected and minimise the calories expended to get it. They’ve even been taught to ‘play golf’ in order to get food, which the researcher considers an example of tool use. All this from a creature that doesn’t have what we understand as a ‘brain’. Who knows what we might discover if we really paid attention?

There are plenty of honeybees about too. Our local allotments have a number of hives, and I suspect that the lavender in the front garden, and the bog plants at the back, are a major draw. There has been a lot written about honeybees and their potential demise just lately, but let’s not forget that the pollinator community is much greater and more diverse than just this one species, iconic and important as it is.

And then there are the hoverflies, so rarely noticed and yet so omnipresent. This one is a marmalade hoverfly (Episyrphus balteatus), our commonest hoverfly, yet I had never noticed the metallic shine on its thorax, which looks almost like liquid copper. For all you hoverfly enthusiasts out there, I can recommend ‘Britain’s Hoverflies’ by Stuart Ball and Roger Morris, an absolute labour of love.

Marmalade hoverfly (Episyrphus balteatus)

The colour of the marmalade hoverfly is very variable, and seems to depend on the temperature when the larvae are maturing – in hot temperatures, the adult will be predominantly orange, but if it’s cold, they can be almost black. The larvae themselves are voracious eaters of aphids, especially those found on cereal crops and cabbages. They might not be as elegant as lacewings or ladybirds, but they are possibly even more important.

Sometimes swarms of marmalade hoverflies arrive from southern Europe, and the media is fond of filling the summer doldrums with reports of ‘wasps’ terrorising the gardens of England. The reporting of all things insect-related in the papers, and on social media, is often enough to make me bash my head against the wall.

The final ‘spotting’ of my 15 minutes was this ‘muscular’ little hoverfly, Siritta pipiens, which has the common name of ‘thick-legged hoverfly’, for obvious reasons. With those enormous ‘thighs’ it could be a candidate for an insect body-building competition. This creature is both common and widespread, and yet I had never noticed it before. Apparently the males are very territorial and will conduct battles in which they push one another backwards and forwards much like a pair of miniature water buffalo.

Syritta pipiens, a very muscular hoverfly…..

And so, I spent a very interesting 15 minutes with the insects. There is nothing like sitting peaceably among the bees and butterflies and hoverflies to give one a sense of perspective. It brings me a sense of being part of something much larger than just my small, transient concerns, and that is very welcome at the moment, as life gently moves on, whether I want it to or not. If you are feeling out of sorts, or dissociated, or generally confused, I can recommend sitting next to some flowering plants and just noticing who turns up. You might just be surprised.

 

 

Wednesday Weed – Meadowsweet

Meadowsweet (Filipendula ulmaria)

Dear Readers, it was such a delight to get back from Austria on Saturday, and to find the meadowsweet that I planted by the pond two years ago in flower. What a splendid plant this is! It has a honeyed scent that reminds me of hay, and it attracts all manner of hoverflies. The buds are almost square, and then the seed heads remind me of those fondant sweets that you can buy in posh places like Fortnum and Masons.

Twisted seedheads plus hoverfly….

Although the garden as a whole has gone completely berserk during this past couple of years, I am very pleased with this spot, where the meadowsweet mixes with hemp agrimony, purple loosestrife and some self-seeded greater willowherb. It is a-buzz with bees and other pollinators, and they are all at head height so I can get a really good look. The fly above, for example, with his/her rather muscular ‘thighs’ reminds me of a mini weighlifter.

Anyhow, to return to meadowsweet. Although the plant likes damp places (and is often known as ‘queen-of-the-meadow’, the name might refer to ‘mead’ , as the flowers were used to flavour many kinds of drinks. It was also used as a strewing herb on floors and in mattresses. In my new favourite book, Vickery’s Folk Flora, it mentions that it was sometimes used on the floors of outside toilets, to disguise the smell.

In Flora Britannica, Richard Mabey mentions that different parts of the plant have different scents: he describes the basic scent of the plant as being like marzipan, tinged with musk and honey in the flowers, but with the sharpness of pickled cucumber in the leaves. Mabey mentions that one ‘cynical namer’ believed that this was the difference between ‘courtship and matrimony’, but he was obviously married to the wrong person.

In spite of its sweet scent, Meadowsweet is yet another of those herbs that it was thought to be unlucky to bring into the house. One of these days I shall compile a list of all the wildflowers that are cause death and bad luck just by being picked and stuck in a vase. One alternative name for meadowsweet was ‘old man’s pepper’, with ‘old man’ being a name for the devil in many parts of the UK. Sniffing meadowsweet with too much enthusiasm was also thought to bring on fits.

In Wales, it is not only considered unlucky to bring it into the house (‘if a person falls asleep in a room where many of these flowers are placed, death is inevitable’), but it is also though to be dangerous to fall asleep in a field where there is an abundance of meadowsweet. However, there is also a legend in Wales that the magicians Gwydion and Math created a woman out of oak blossom, broom and meadowsweet, and called her Blodeuwedd, or ‘Flowerface’. She was created to be the wife of Lleu, who was cursed to never be able to marry a human wife, but had other ideas, and arranged for him to be murdered. This was no easy task:

Blodeuwedd tricks Lleu into revealing how he may be killed, since he cannot be killed during the day or night, nor indoors or outdoors, neither riding nor walking, not clothed and not naked, nor by any weapon lawfully made. He reveals to her that he can only be killed at dusk, wrapped in a net, with one foot on a bath and one on a black goat, by a riverbank and by a spear forged for a year during the hours when everyone is at Mass. With this information she arranges his death’.

However, Lleu is nursed back to health by the magicians who created Blodeuwedd in the first place, and she is turned into an owl for her pains. It just goes to show that crime never pays.

The legend was the inspiration for Alan Garner’s 1967 young adult novel ‘The Owl Service’, which explores what it mean to be Welsh, the class divide and the eternal power of stories. Well worth a read, even if you’re way past being a ‘young adult’.

Photo One by By E. Wallcousins - 'Celtic Myth & Legend', Charles Squire,, PD-US, https://en.wikipedia.org/w/index.php?curid=29984364

Blodeuwedd meeting Gronw, the man who will kill her husband (Photo One)

Here, though,  I’d like to back up a little and give some basics on the plant. Meadowsweet is native to the UK and can be found in damp spots throughout Europe and western Asia. It is also naturalised in some parts of North America. It is a member of the rose family (Rosaceae) which I would never have guessed, though the leaves do look a little rose-like.

The plant contains salicin, which is related to salicylic acid (aspirin) – in fact, the drug was named from the old botanical name for meadowsweet, Spiraea ulmaria. Having just returned from Austria, I was interested to learn that the Austrians make a tea with meadowsweet, and use it for the treatment of painful conditions such as rheumatism and gout.

The Bronze Age burial sites of three humans and one animal at Fan Foel in Carmarthenshire, Wales, have contained the remains of meadowsweet, probably used as a strewing herb, and the signature of the plant has also been found in grave goods in Scotland from the same period, probably as a result of meadowsweet being used to flavour wine that was buried alongside the dead.

Meadowsweet has a reputation as a dye plant – the roots are supposed to give a black dye when used with a copper mordant (fixative). The genus name ‘Filipendula‘ relates to the way that the root tubers hang off of the fibrous roots (the Latin word means ‘hanging thread’). To read about various experiments using different parts of meadowsweet with different mordants, have a look at the wonderful ‘Wool Tribulations’ blog here 

Photo Two from http://wooltribulations.blogspot.com/2014/07/a-trial-of-meadowsweet-plant-dye-on.html

The author of ‘Wool Tribulations’, Fran Rushworth, has created some great effects from using meadowsweet (Photo Two)

In addition to its obvious attraction for hoverflies, the leaves of meadowsweet are munched upon by no fewer than 16 species of moths, including the magnificent emperor moth (Saturnia pavonia). How excited I would be if one of these turned up!

Photo Three by By jean-pierre Hamon - Own work, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=524340

Emperor moth (Saturnia pavonia) (Photo Three)

The caterpillars are pretty magnificent too.

Photo Four by By Thomas Tolkien from Scarborough, UK - Emperor Moth caterpillarUploaded by herkuleshippo, CC BY 2.0, https://commons.wikimedia.org/w/index.php?curid=12704087

Emperor moth caterpillar (Saturnia pavonia) (Photo Four)

The leaves of meadowsweet can also be injured by the meadowsweet rust gall, which is a fungus which chemically induces a bright orange swelling on the mid rib of the leaf. It can cause serious problems in young plants, so I shall keep an eye open. The last thing I want is for my newly established meadowsweet patch to keel over.

Photo Five by By Rosser1954 Roger Griffith - Own work, Public Domain, https://commons.wikimedia.org/w/index.php?curid=7040901

Meadowsweet rust fungus (Triphragmium ulmariae) (Photo Five)

And, of course, a poem. For those of you who haven’t come across the Scottish poet and writer Kathleen Jamie, I can heartily recommend her books ‘Findings and  ‘Sightlines’, and her poetry collections ‘The Tree House’ and ‘The Overhaul’. I love her for many reasons, not the least of which was her piece about Robert MacFarlane’s book ‘The Wild Places’, called ‘A Lone Enraptured Male‘. If you haven’t read it, you can read it here. It made me roar with laughter and nod in agreement (and I speak as someone who loved MacFarlane’s recent book ‘The Underland’.

And here is her poem.

Tradition suggests that certain of the Gaelic women poets were buried face down.
So they buried her, and turned home,
a drab psalm
hanging about them like haar,

not knowing the liquid
trickling from her lips
would seek its way down,

and that caught in her slowly
unravelling plait of grey hair
were summer seeds:

meadowsweet, bastard balm,
tokens of honesty, already
beginning their crawl

toward light, so showing her,
when the time came,
how to dig herself out —

to surface and greet them,
mouth young, and full again
of dirt, and spit, and poetry.

Photo Credits
Photo One by By E. Wallcousins – ‘Celtic Myth & Legend’, Charles Squire,, PD-US, https://en.wikipedia.org/w/index.php?curid=29984364
Photo Three by By jean-pierre Hamon – Own work, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=524340
Photo Four by By Thomas Tolkien from Scarborough, UK – Emperor Moth caterpillarUploaded by herkuleshippo, CC BY 2.0, https://commons.wikimedia.org/w/index.php?curid=12704087
Photo Five by By Rosser1954 Roger Griffith – Own work, Public Domain, https://commons.wikimedia.org/w/index.php?curid=7040901

Wednesday Weed – Columbine

Columbine (Aquilegia vulgaris)

Dear Readers, this seems to have been a particularly good year for columbines.They are the quintessential cottage garden plant, but I was surprised to discover that the small flowered blue form, as seen above, is a native. Because various forms of columbine are grown so frequently in the garden it’s hard to determine what the actual range of the plant is, but Aquilegia, a genus of about 70 species, are found throughout the northern hemisphere. Aquilegia vulgaris seems to like calcium-rich soils, woodland areas and damp grassland, and is most common in the south and west of the UK – I found the flowers in the photos today in Somerset and Dorset.

Columbine has many, many local names. Most refer to the shape of the flowers: my Vickery’s Folk Flora tells me that the plant is known as ‘Doves-in-the-ark’ in Somerset; the name ‘Columbine’ comes from the Latin word for dove, ‘columba‘, with the inverted flower being said to resemble five doves clustered together. In Yorkshire it’s called ‘Fool’s hat’, a reference to flower’s resemblance to a jester’s cap. In Wiltshire it bears the name of ‘Granny-jump-out-of-bed’, possible because the petals resemble a skirt, though why granny was wearing her clothes in bed would probably make a story all on its own. ‘Aquilegia’ means ‘eagle-like’, and this is because the petals are supposed to look like an eagle’s claw.

The wild form of columbine is usually dark blue, though it can also be found in pale pink and white. However, the ‘domesticated’ forms come in a huge variety of colours and flower shapes. Here are a selection: first, the cultivar ‘Magpie’

Photo One by By JJ Harrison (https://www.jjharrison.com.au/) - Own work, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=5516707

‘Magpie’ cultivar (Photo One)

Then this rather pretty blue cultivar

And this pink one….

Pink flowered columbine (Public Domain)

And a double-flowered one for good measure.

Double-flowered columbine (Public Domain)

What is interesting about the structure of the columbine, however, is that it is the spurs at the back of the flower hold the nectar. The length of these structures varies from species to species, but in all wild plants the spurs have evolved to match the bird or insect that pollinates it. In California, Aquilegia pubescens (also known as the Sierra columbine) is a high-altitude plant that has white flowers, and spurs up to 5 centimetres long. The plant is pollinated by hawk moths, insects with a liking for white-flowered plants and with a tongue long enough to reach the nectar.

Photo Two by By Dcrjsr - Own work, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=10776732

Sierra columbine (Aquilegia pubescens) (Photo Two)

At lower altitudes, from Alaska to Baja California is the crimson columbine (Aquilegia formosa). Its red colour and much shorter spurs are a giveaway that its main pollinators are hummingbirds (most red-flowered wild plants were originally bird-pollinated). In between there are a whole host of hybrids between the two species, illustrating the way that the plant is adapting to the chief pollinators in each area. The process illustrates the way that plants and pollinators are locked into a dance of evolution, with each dependent on the other.

Photo Three by Dcrjsr - Own work, CC BY 4.0, https://commons.wikimedia.org/w/index.php?curid=50586172

The transition from Aquilegia pubescens to Aquilegia formosa (Photo Three)

Photo Four By Walter Siegmund (talk) - Own work, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=5491242

Crimson columbine (Aquilegia formosa) (Photo Four)

For anyone who would like a closer look at the structure of the columbine flower, I recommend the UK Microscopy website, which has many fascinating insights. One of these days I shall treat myself to a microscope, maybe for my fast-approaching sixtieth birthday – I love the way that a close-up view reveals so many wonders. But in the meantime I shall keep going to UK Microscopy for my high-magnification fix.

In the UK, columbine is a good bee plant, and is a nice choice for a woodland garden. It attracts mainly long-tongued bumblebees, and as seven of these species are considered endangered, it is well worth popping a few columbines into your understorey (should you have one). The bumblebee with the longest tongue in the UK is the garden bumblebee (Bombus hortorum), who has a tongue which can reach 2 cms long and is hence a match for any native columbine. My advice is to avoid the highly-bred fancy cultivars, and go for the dark blue natives.  Plus, you don’t have to worry about isolating individual cultivars or even species in order to get them to ‘come true’ – as we have seen, columbines hybridize at the drop of a hat.

Photo Five by Roo72 [CC BY-SA 3.0 (https://creativecommons.org/licenses/by-sa/3.0)]

Bee pollinating columbine (Photo Five)

There seems to be some debate over whether Aquilegia vulgaris (‘our’ columbine) is poisonous – they are members of the Ranunculaceae or buttercup family, and are closely related to monkshood (Aconitum napellus), described as ‘the most toxic wild plant in Britain’. Some sites described the roots and stems as being toxic, and on the Poison Garden website, the dark columbine (Aquilegia atrata), which is native to northern Europe, is said to have been used to cause miscarriage. However, there are no recorded cases of poisoning, and it is often a favourite in children’s gardens because of its interesting flowers and bee-attracting properties. Plus, certain Native American tribes have long eaten the flowers, which I imagine are very sweet due to the concentrated nectar that they contain.

St. Hildegard of Bingen (1098-1179) used the plant medicinally as a treatment for swollen glands, and it was also used to hasten childbirth. As with most herbal remedies, the dosage and the wisdom and understanding with which the plants were used has been largely lost, to all of our detriment.

Many species of moth caterpillar munch upon the poor old columbine, and one of them is the saddleback looper, the larva of The Engrailed (Ectropis crepuscularia). The moth is not particularly exciting to look at, but I include it here because I have learned that the word ‘engrailed’ means ‘to have semicircular indentations along the edge’ in heraldry. You’re welcome.

Photo Six by By ©entomartIn case of publication or commercial use, Entomart wishes then to be warned (http://www.entomart.be/contact.html), but this without obligation. Thank you., Attribution, https://commons.wikimedia.org/w/index.php?curid=806463

Adult male Engrailed moth (Ectropis crepuscularia) (Photo Six)

A plant which has been grown in the UK since the 13th century is bound to have attracted some folklore, and one story is that lions ate columbine in order to give themselves strength – it was said that, to get the courage of a lion, all you needed to do was to rub the plant over your hands. However, if you are female and someone gives you a bunch of columbine, this is an indication that you are said to have ‘flexible morals’, and I think you would be well within your rights to summon up the courage of a lion and ‘clip them round the ear’ole’ as my Dad used to say.

And, of course, a poem or two. When I looked for ‘Columbine poems’,  I found many, many works about the school shooting at Columbine, a great outpouring of grief and rage and questioning. But I was most intrigued by, firstly, this work by Melissa Stein, who we encountered a few weeks ago writing about lily of the valley.

Dear Columbine, Dear Engine

by Melissa Stein

Dear columbine, dear engine.
Mere water will force a flower
open. Then with a touch
the beautiful intact collapses
into color filament and powder.
It’s all my fault. All hands on deck
to help collect what’s spilled.
That could be me beneath
a bridge. Torn up beside the road,
a bloat of skin and fur.
Afloat in bathtub, clean,
blue-lipped, forgiven. Face-down
in the snow. Why do you
imagine these terrible things?

asks my mother, or her
ghost. Because the paper’s
crisp and white. Because
no slate’s unwritten.
Because the ant that scaled
this flower head
has nowhere else to go.

And to end on a less distressing note, here is Emily Dickinson. There is a fine blogpost here by someone who is reproducing Emily Dickinson’s garden, and what a lovely idea that is.

It’s Father’s Day here today as I write, and for some reason this poem made me think of my mother. See what you think.

Columbine

by Emily Dickinson

Glowing in her bonnet-
Glowing in her cheek-
Glowing is her Kirtle-
Yet she cannot speak.

Better as the Daisy
From the summer hill
Vanish unrecorded
Save by tearful rill-

Save by loving sunrise
Looking for her face.
Save by feet unnumbered
Pausing at the place.

Photo Credits

Photo One by By JJ Harrison (https://www.jjharrison.com.au/) – Own work, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=5516707

Photo Two by By Dcrjsr – Own work, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=10776732

Photo Three by Dcrjsr – Own work, CC BY 4.0, https://commons.wikimedia.org/w/index.php?curid=50586172

Photo Four By Walter Siegmund (talk) – Own work, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=5491242

Photo Five by Roo72 [CC BY-SA 3.0 (https://creativecommons.org/licenses/by-sa/3.0)]

Photo Six by By ©entomartIn case of publication or commercial use, Entomart wishes then to be warned (http://www.entomart.be/contact.html), but this without obligation. Thank you., Attribution, https://commons.wikimedia.org/w/index.php?curid=806463

Wednesday Weed – Foxglove

Foxglove (Digitalis purpurea)

Dear Readers, I can never get past my mental image of a fox tiptoeing around the garden wearing pink ‘gloves’ on each foot when I look at this plant. The allusion goes right back to the Anglo Saxon, when it was known as ‘foxes glova‘, and the Latin name digitalis means ‘finger-like’. In some parts of the country it is also known as fairy gloves. I remember putting the spent blooms on my fingers and drawing little faces on them when I was a child, and Richard Mabey reports how, by leaving the stem of each flower intact, they can be turned into ‘claws’. In Vickery’s Folk Flora, there are many tales of children using the flowers as tiny balloons, holding each end of the flower and pushing the ends until they popped. It was also considered a great game to capture a bumblebee inside one of the flowers, and to delight in its frantic buzzing. In the Forest of Dean, foxgloves were known as ‘snowpers’, and a favourite admonition to a noisy child was ‘Shut thee chops; thee bist like a bumble bee in a snowper’. Certainly these always feel like the most playful of plants, and from memory they seemed to be in full bloom at just about the time that the school holidays started.

Foxgloves are certainly having their moment ‘in the sun’ (though they are actually woodland flowers and most varieties don’t thrive without some shade). Every time I go to the garden centre there seem to be new varieties in every shade of cream, apricot, white and pink. They are biennials, bulking up during year one and producing flowers in year two. They self-seed enthusiastically, and are beloved by bumblebees. Digitalis purpurea is native to most of temperate Europe, but is also naturalised in many parts of North America. It is, rather counter-intuitively, a member of the plantain family (Plantaginaceae) which has been muchly enlarged of late.

White foxgloves in my garden

The story of foxgloves, however, is most closely associated with its toxicity and its medicinal properties. The leaves of foxglove were long used as a diuretic against dropsy (fluid accumulation), but it was also known that foxglove was toxic, and that giving the wrong dosage could be fatal. In Flora Britannica, Richard Mabey describes how it was a study of the plant’s usage by botanist and physician William Withering that created the split between traditional herbalism and modern pharmacology.

Withering realised that the principal action of foxglove was on the heart, slowing and strengthening its beat and hence, in dropsy, stimulating the kidneys to clear fluid from the body. He also noted that the leaf could be useful in cases of heart failure. However, he insisted on carefully measured doses of the dried leaf, and was aware that too high a dose could cause the heart to falter and cease. Over time, the foxglove’s key active ingredient, digitalis, was isolated and purified, and is used today (as digitoxin and digoxin) for heart conditions. Incidentally, if you have an elderly relative taking either of these drugs who seems to be in a habit of falling, do check that the drug is not lowering blood pressure too much. Dad had six falls in as many months until a junior doctor checked his medication and realised what was happening.

These days, the chemicals for medication are largely prepared from imported leaves of a European foxglove, Digitalis lanata. However, during both World Wars the leaves were gathered and dried by members of The Womens’ Institute, just to make sure that there was an adequate supply. In 1941 the women of the Oxfordshire Women’s Institute collected enough foxglove leaves to provide 350,000 doses of the drug (enough to treat 1,000 patients for a year). Never underestimate a group of woman on a mission.

Although the plant is very poisonous, it is also emetic, which means that you are likely to vomit before suffering the worst cardiac effects. However, it was used as a salad ingredient by someone trying to murder their husband (in Colorado in 2010). The husband realised that the salad tasted bitter, but thought it was one of these antsy-fancy new leaves that are all the rage (I can relate). He suffered a gastrointestinal upset but survived, and his wife was sentenced to four and a half years in jail.

In the Vickery book mentioned earlier, it seems that foxglove was also used for a deeply sinister purpose: the killing of unwanted children. There are several folk legends indicating that foxglove is poisonous to ‘fairies’, and it was used as a test to see if a sickly child was a changeling ( a fairy child who had been exchanged for the original human child) in both County Leitrim and Caernarvonshire, the latter as recently as 1857. A child was given a small dose of foxglove, and it was believed that if the child was human, it would survive, whereas if it was a fairy it would die. It would not take a very large dose to kill a child, especially one who was already ill.  Vickery comments that

Thus it seems that the use of foxglove (and other ordeals to which supposed changelings were subjected) might have been an acceptable method of infanticide which enabled families to rid themselves of sickly offspring‘.

Photo One by By i_am_jim - Own work, CC BY-SA 4.0, https://commons.wikimedia.org/w/index.php?curid=68449634

Photo One

The poisonous nature of the plant doesn’t put off the caterpillars of the foxglove pug moth (Eupithecia pulchellata), who feed on the internal parts of the flowers, after sewing them shut with silk. Both moth and caterpillar are unassuming in appearance, but for sheer ingenuity I think they deserve a brief moment of fame here.

Photo Two by user janenannierocks at waarneming.nl, a source of nature observations in the Netherlands. - This image is uploaded as image number 3702949 at waarneming.nl, a source of nature observations in the Netherlands.This tag does not indicate the copyright status of the attached work. A normal copyright tag is still required. See Commons:Licensing for more information., CC BY 3.0, https://commons.wikimedia.org/w/index.php?curid=20563006

A foxglove pug (Eupithecia pulchellata) (Photo Two)

And now, a picture. Regular readers will know of my fondness for Vincent Van Gogh, who loved flowers of all kinds so much that I believe he saw into their innermost nature. The portrait below shows Dr Paul Gachet, a homeopath and medical doctor, who took care of Van Gogh following his release from the asylum at Saint-Remy-de-Provence, and was with the artist for the last few months of his life. Following an inauspicious start, Van Gogh grew to love Dr Gachet, describing him as ‘a true friend, something like another brother’. The portrait shows Dr Gachet with a bunch of foxgloves, probably as an indication of his medical background. Van Gogh painted two versions of the picture, and said that:

“I’ve done the portrait of M. Gachet with a melancholy expression, which might well seem like a grimace to those who see it… Sad but gentle, yet clear and intelligent, that is how many portraits ought to be done… There are modern heads that may be looked at for a long time, and that may perhaps be looked back on with longing a hundred years later”.

Six weeks later, Van Gogh shot himself in the woods surrounding Dr Gachet’s home.

In 1990 the painting was bought by Ryoei Saito, chairman of the Daishowa Paper Manufacturing Co, for $82m, making it the world’s most expensive painting at the time. The 75 year-old businessman was so fond of the painting that he threatened to have it cremated with him. When Saito died in 1996, the painting seems to have been sold, but the new owner suffered financial problems and sold it on again. Like so many masterpieces, it is probably now in a vault somewhere, or in a secret private collection.

Portrait of Dr Gachet by Vincent Van Gogh (1890) (Public Domain)

And of course, a poem. Here is ‘The Miracle of the Bees and the Foxgloves’ by Anne Stevenson, which manages to combine close observation with a sly humour.

The Miracle of the Bees and the Foxgloves

Because hairs on their speckled daybeds baffle the little bees,
foxgloves come out to advertise for rich bumbling hummers,
who crawl into their tunnels-of-delight with drunken ease
(see Darwin’s chapters on his foxglove summers)
plunging over heckles caked with sex-appealing stuff
to sip from every hooker its intoxicating liquor
and stop it propagating in a corner with itself.
And this is how the foxflower keeps its sex life in order.
Two anthers—adolescent, in a hurry to dehisce—
let fly too soon, so pollen lies in drifts around the floor.  
Along swims bumbler bee and makes an undercoat of this,
reverses, exits, lets it fall by accident next door.  
So ripeness climbs the bells of Digitalis, flower by flower,
undistracted by a Mind, or a Design, or by desire.
Notes:

In eight pages of The Effects of Cross- and Self-Fertilisation in the Vegetable Kingdom (London, 1876: 81–88), Charles Darwin describes an experiment he began in June 1869 among the fox- gloves of North Wales, this just one of his thousands of experiments demonstrating the superiority of cross-fertilization and throwing light on the origin of sexuality.
Photo Credits
Photo One by By i_am_jim – Own work, CC BY-SA 4.0, https://commons.wikimedia.org/w/index.php?curid=68449634

 

Photo Two by user janenannierocks at waarneming.nl, a source of nature observations in the Netherlands. – This image is uploaded as image number 3702949 at waarneming.nl, a source of nature observations in the Netherlands.This tag does not indicate the copyright status of the attached work. A normal copyright tag is still required. See Commons:Licensing for more information., CC BY 3.0, https://commons.wikimedia.org/w/index.php?curid=20563006

Settling Back

Dear Readers, I am now home for eighteen whole days, which is my longest stay in East Finchley for at least a year. But before I tell you about London, I want to give you an update from my latest visit to Dad’s nursing home in Dorchester. Dad was chatting away to a new chap  when I arrived at the home. P had been in the forces and had lived abroad extensively, and, as Dad travelled a fair bit when he was a gin distiller, they were gently ‘one-upping’ one another with tales of jaunts abroad. I have learned that while people with dementia don’t always get their facts in perfect order, there is normally a kernel of truth in what they say however confused they are, and I have no doubt that P had lived in the Far East, and had learned Japanese.  P had a postcard from his daughter which he was showing to everyone who came in. Dad had been planning to write a letter to me, my brother and Mum, and had started to write it on one of the handkerchiefs that I bought him, but when I asked him about it he’d forgotten what he wanted to write. I was surprised both that he could still spell my name, and that he could still write. I’ve left him with a pad and some pens in case the urge to write strikes him again.

Dad’s face absolutely lights up when I walk in, and it’s one of the greatest joys of my life. I tell him when I’m going to visit him, but he always forgets. This time, he grabbed my hand and kissed it.

‘I didn’t know you were going to come in’, he said, and cried.

Dementia has made Dad more emotional, gentler. He has developed a taste for Portuguese custard tarts and ‘frothy coffee’, and it touches me how much he enjoys both of them. I thought that maybe he would be upset by the unusual behaviour of some of the other residents, but he seems completely at ease with them, and sometimes tries to help if someone has ‘lost’ something or seems particularly distressed.

One lady asked if I’d seen her daughter, and I told her that I hadn’t seen her today, but I was sure she’d  be in soon (she visits her Mum very regularly).

‘She’s the best girl in the world’, said the lady, and I had to go outside because that was what Mum always said about me.

One of the guys, B, used to be a London taxi driver and hasn’t lost any of the repartee. One of the carers asked him if he liked children.

‘I like children but I couldn’t eat a whole one’, he said.

When I popped in on Wednesday to have breakfast with Dad and to say goodbye, he was all geared up to ‘walk into town and have a look at a secondhand car’. I know that Dad misses driving, but while I’m sure he could do the mechanics of driving, he wouldn’t know where he was going. Fortunately, the home had organised a trip to the local market, and Dad was going to help choose some plants for the garden.

‘We’ll have a look at the cars if we can find any’, said the carer.

Initially I was really disconcerted at the degree to which I needed to lie to Dad about what was going to happen, and yet the alternative is so much more distressing and painful for him. No one is going to tell him that he will never own a car or drive again, and so the constant promise of it in the future keeps him calm and happy. There was a positive spring in his step as he headed off with his zimmer frame to get his jacket on, and I know that once he’s in the market he’ll be distracted by all the minutiae of tomato varieties and which geraniums are best.

As I waved goodbye, all the other residents waved as well. It really is a little family.

And yet when I got back to London, I was having a coffee and got into a chat with a lady who had a little dog. We talked about pets for a bit, and then I mentioned that I was just back from visiting with my Dad who has dementia. She sympathised, and then, as she was getting up to go, she turned and said

‘Oh, I do hope it doesn’t drag on too long for you’.

And yet again I was lost for words. I know that dementia is a terminal and progressive disease, but really? I think not just about my dad, but about all the people in the home that I’m getting to know, and I know that not only do they have a quality of life that makes it worth living, but that they are still valuable, loving human beings. This is the fourth time in the past six months that someone has suggested that my Dad and his friends would be better off dead, and that I must be hoping for such a speedy outcome. What does it say about our society that we can wish the oldest and most vulnerable people in it dead? My Dad is teaching me lessons about compassion and patience and understanding every single day.

And so, I really needed the solace of the garden when I got home, and all kinds of things were going on.

Take the fabulous cabbage palm (Cordyline australis) next door, for example. This year it is carrying three whole spikes full of flowers which are constantly abuzz with honeybees. I went outside to take a photograph and realised how sweet-smelling it is. No wonder the bees love it.

Outside the back door, I notice that everything is hideously overgrown, and that the pond is turning into a bog as fast as I can pull things out. However, some yellow flag irises are flowering for the first time this year. I can’t even remember planting them, so maybe they came with something else. This will certainly be something for the dragonfly larvae to climb up, and I check every day just in case.

And I love the way that the sunlight touches the water. The pond is absolutely full of frogs of all sizes this year, from adults to tiny new froglets the size of my fingernail. They are hanging around a lot later this year too, so maybe being so overgrown isn’t such an absolutely bad thing.

My white foxgloves are flowering, and the Bowles Mauve perennial wallflower is covered in bumblebees.

And so is the mock orange, which is just finishing but which is still headily-scented.

But there has been one disaster. The box moth caterpillars have been particularly vigorous this year – last year I managed to trim the bush back in the spring and get rid of most of the damage, but this year they have killed the bushes completely. I shall be cutting them back, digging them out and planting something else. I even spotted one of the caterpillars walking nonchalantly across the path a few days ago, probably en route from one bush to another. This is a pest that has marched through the  country over the past ten years, although the adult moth is rather lovely. I spotted the first one I’d ever seen at the Barbican Centre in London in 2015, but it was noticed in private gardens in 2011. It has probably arrived in imported box plants (the moth comes originally from East Asia) and while it can be treated with nematodes if caught in the early stages, the advice from RHS Wisley is to plant something else. Climate change is making the environment much more pleasant for the moth, and I suspect that we are going to have to adapt too. Privet, anyone?

RIP to my box bush.

Adult Box Worm Moth (Cydalima perspectalis)

And, in more exciting news, we are going to get our external decorations done. It’s been more than ten years, and the paintwork is, shall we say, a bit on the dodgy side. The scaffolding is up, but the best news is that I have bought this.

A sparrow nesting box

Sparrows like to nest communally, and so I have this little terrace of nestboxes that I have persuaded the decorator to put up for me while he’s on the scaffolding. Sparrows have already been investigating the eaves but have never stayed, so I am very hopeful that maybe next year they’ll take up residence. And if they don’t, maybe somebody else will. And once that’s done, I shall be looking into getting the garden back into some kind of order. I need to move my centre of gravity back east from Dorset, and start getting back into my own life. It will be interesting to see how that works out.

Roxanne geranium in the garden

Cuckoo Spit and Xylella – The Story So Far

Cuckoo Spit on the lavender in the front garden

Dear Readers, I am a member of several garden wildlife and insect groups online, and during this past week I have seen a rise in questions along the lines of ‘ I have cuckoo spit on my lavender, should I hose it all off? Is there any way to get rid of it? Are we on the verge of Armageddon?’ As someone who is entranced with the miracle of these annual foamy masses and the insects that make them, I figured that someone had gotten hold of the wrong end of the stick, and so they have. Reports that have superficially demonised the froghopper have appeared on the BBC and in most major and local newspapers, and I am frankly bewildered by the lack of knowledge shown. Science is often complicated, and it’s sometimes easy to read a headline and panic. So here is what is happening, as I understand it, and here is what we should be doing.

  1. What is cuckoo spit?

Cuckoo spit is produced by the nymph of the froghopper, a ‘true bug’ which feeds on the sap of plants such as lavender and rosemary. The froth is a protection for the toothsome youngster: it is produced from the insect’s excreta, and is turned into froth by the creature passing air through its anus. As I put it in my original piece on froghoppers here,

‘The foam is the only protection that Froghoppers have, and schoolchildren are always delighted by how it’s made. The bug sucks up the sap from its chosen plant, excretes what’s left, and blows air through it – so, it lives in a house built from faeces, and created by flatulence. What youngster could resist such a story? I’m surprised that they’re not all queueing up to be biologists as we speak.’

2. Do froghoppers do any harm?

The RHS website says that froghoppers rarely cause any real damage to plants, and can be left unmolested. I concur. My lavender has been a-froth with froghoppers for years, and is still splendid.

Froghopper nymph denuded

3. So why all the sudden fuss?

A bacterial disease known as Xylella fastidiosa, first discovered in the US in the 1890’s, is on the move. It turned up in Brazil at the end of the 20th Century, was in Europe by 2013 and has been advancing at a surprising pace. It was previously thought to be confined to warm areas such as the olive plantations of Greece, but in the past few years it has been found in France and Germany. Xylella works by blocking the uptake of water to the plant, and can be devastating – it has been identified in over 560 species of plant worldwide. In the UK, trees such as the oak and plane are thought to be most at risk. The RHS and DEFRA have been putting plans in place to arrest the spread of the disease if (or more likely when) it arrives. It is not, as far as we know, here yet.

The disease is probably going to arrive in the UK via a plant imported by a garden centre or tree nursery.  – the most recent outbreak of the disease was in Oleander, a popular garden plant in this country. However, once here it could be transmitted via sapsucking insects such as the froghopper. Although froghoppers are homebodies and don’t usually move more than about 100 metres during their lifetimes, they can be carried much further by the wind.

Photo One by By Charles J Sharp - Own work, from Sharp Photography, CC BY-SA 4.0, https://commons.wikimedia.org/w/index.php?curid=38317620

An adult froghopper (Philaenus spumarius) waiting to ping away. It is a very froggy-looking creature! (Photo One)

4. Why all the requests to report cuckoo spit?

This is pre-emptive. It’s hoped that by building up a picture of where froghoppers are at the moment, it will be easier to understand exactly when the insects are active and the extent of their range.  I will be reporting my froghoppers to the iRecord site below, which can be used to report other critters too, and is very useful for getting a picture of what’s around in your local area. You will need to set up an account, and then you are looking for a ‘project-specific record’ – the project is ‘xylem-feeding insects’, and the common cuckoo spit froghopper’s Latin name is Philaenus spumarius. There is a useful pictorial guide here, just in case you have one of the other two common British species.

https://www.brc.ac.uk/irecord/

5. What is being done to fight the disease?

Certain EU regulations are already in place to control the spread of the disease: this is from the Henry Doubleday website.

  • All plant importers have to show evidence that their plants are sourced from areas that are free from Xylella.
  • Proposed imports of host species such as plane, elm and oak plants must be pre-notified to the UK plant health authorities to enable inspection This will allow a sequence of spot checks at the UK borders.
  • Other regulations are in place that restrict movements of specified host plants from the infected region of Apulia in southern Italy, and from countries outside the EU, to reduce the risk of entry.

However, if it did become established in the UK, control would focus on the targeted removal of host plants and management of the vector insects’ habitats. An outbreak (as opposed to an isolated incidence) would mean eradication of all possible hosts within 100m of the outbreak and very tight restrictions on commercial plant producers or garden centres within 10km of the outbreak for 10 years.

In other words, this is an extremely strong incentive to garden centres to ensure that their plants are properly sourced.

Photo Two by By I, Pompilid, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=2260500

Oleander infected by Xylella (Photo Two)

6. What plants does DEFRA consider are most at risk?

In addition to the oak and plane, there are a whole range of other plants who would be endangered by Xylella.

  • Acer rubrum L.
  • Catharanthus roseus (L.) G.Don
  • Citrus sinensis (Linnaeus) Osbeck
  • Coffea L.
  • Gramineae Adans., Nom. Cons.
  • Medicago sativa L.
  • Morus rubra L.
  • Nerium oleander L.
  • Platanus occidentalis L.
  • Prunus L.
  • Prunus persica Batsch
  • Quercus rubra L.
  • Ulmus americana L.
  • Vaccinium L.
  • Vinca minor L.
  • Vitis L.
  • Woody plants
  • Liliaceae (family)
  • Citrus

7. What are the symptoms of Xylella?

Unfortunately, Xylella can look rather like many other diseases. The Forestry Commission says that:

‘The visible symptoms on plane, maple (Acer), oak and elm trees include leaf scorch, sometimes also with dieback of twigs and branches. The characteristic leaf symptoms which are visible in summer include browning at the leaf margins (but not along the main veins), and there is often a yellow edge to the browned areas.’

I suspect that concrete identification can only be achieved by scientists with microscopes. The bacteria produces many different species-specific syndromes, varying from oleander leaf scorch to citrus variegated cholorosis to olive quick decline syndrome. You will have noticed that many of the plants attacked are important food crops, often intensively grown and lacking in genetic diversity. There is much to be said for proper husbandry and stocking, and for the preservation of different varieties of plants, for just this situation.

The bacteria works by blocking the xylem, the main water-transport system of the plant. If only a few vessels are affected, the plant might be asymptomatic but still a carrier of the bacteria. If it is planted elsewhere and subsequently fed upon by a froghopper, the bacterium can be spread to another plant. The infected plant can also transmit the disease if it is grafted to a healthy plant.

Photo Three by Alexander Purcell, University of California, Bugwood.org - [CC BY 3.0 (https://creativecommons.org/licenses/by/3.0)]

Pierce’s disease, caused by Xylella, on citrus (Photo Three)

8. Do we have to worry now? Should I be hosing off my froghoppers and burning my lavender?

No. As mentioned above, the reporting of cuckoo spit is pre-emptive. Our froghoppers are currently completely innocent, and will hopefully remain uninfected with Xylella. I think it is a hopeful sign that DEFRA and other bodies are getting on the case now, in unison with the EU, in order to head this threat off at the pass before it gets to the UK. We have already lost our elms, are likely to lose most of our ash trees, and our horse chestnuts are under siege every year. Let’s hope that this will be one disease that doesn’t get a grip.

Photo Credits

Photo One by By Charles J Sharp – Own work, from Sharp Photography, CC BY-SA 4.0, https://commons.wikimedia.org/w/index.php?curid=38317620

Photo Two by By I, Pompilid, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=2260500

Photo Three by Alexander Purcell, University of California, Bugwood.org – [CC BY 3.0 (https://creativecommons.org/licenses/by/3.0)]