Category Archives: Conservation

Conservation, Natural History, Nature Reserves

Summer Bugs at Gunnersbury Triangle

Cinnabar Moth on rusty False Oat Grass
Cinnabar Moth on rusty False Oat Grass

Ragwort is at full height now and will soon be flowering. A few adult Cinnabar Moths are about; they will mate and lay eggs on the ragwort, which is in several places around the reserve, and then we will have the fine black-and-orange banded caterpillars in quantities, eating the Ragwort to pieces. They are poisonous with alkaloids taken up from the plant, so few predators eat them: an exception is the Cuckoo, which seems able to cope with the chemistry.

Iris Sawfly on Yellow Iris, with examples of how it damages leaves
Iris Sawfly on Yellow Iris, with examples of how it damages leaves

Iris sawfly caterpillars are starting to chew inroads into the spearblades of the Yellow Iris; they are rather like moth caterpillars, but with rows of little dots on their backs and different numbers of prolegs.

Fox run down grassy bank
Fox run down grassy bank

It looks as if there are young foxes about; a very well-worn run goes straight up the grassy bank into the bushes, and the grass nearby is much trodden down.

Neighbours
Neighbours

The new buildings towering over the reserve are approaching their final shape; it will be a relief when the roar of heavy engines and the squeal and clatter of caterpillar-tracked bulldozers subside into history. There was a horrible accident on the building site this week when something fell from a crane; three workers were injured, one seriously, and the air ambulance arrived, followed by the health and safety inspectors.

 

Conservation, Environment, Natural History

Orchids Surviving, Butterflies Vanishing in West Wiltshire

I had the good fortune to get down to West Wiltshire in hot if sometimes humid summer weather.

Pyramidal Orchid in Flowery Meadow
Pyramidal Orchid in Flowery Meadow

It was a pleasure to find the Pyramidal Orchid in a flowery meadow near a town: despite the dog-walkers, the increasingly uncommon flowers were clearly spreading from a small patch across the meadow, which is mown annually.

Less pleasantly, there were next to no insects pollinating the flowers: we saw one Small Tortoiseshell, a fly or two, and one (white/buff-tailed) bumblebee. It was a stark contrast to the masses of bees and beetles I’ve seen on the reserve in London. Of course, in London there is now very little use of pesticides, and basically none on an industrial scale.

This year (2014) does seem to be particularly poor for butterflies. It was an extremely warm winter and a very wet and windy spring, so I wonder if the result has not been a bad spring for insect pests … and perhaps, whether England’s farmers have not sprayed insecticide especially heavily? It’s a question that could clearly be answered by someone. If the answer is yes, then our ‘useful insects’ have suffered very heavily as a consequence.

The next day we went to Cley Hill, a western outlier of the Salisbury Plain chalk downs, sticking up above the plain below the chalk escarpment.

Bee Orchid
Bee Orchid

In the short grass, full of lovely flowers – Sainfoin, Milkwort, Horseshoe Vetch – were Bee Orchids, and happily both bumblebees in this special place protected by the National Trust and Burnet Moths – mostly Five-Spot Burnet, with some Transparent Burnet too, quite a treat.

Five-Spot Burnet Moth
Five-Spot Burnet Moth
Transparent Burnet Moth
Transparent Burnet Moth

On the top of the hill, above the Iron Age earthworks, we came across a group of about five Wall Brown butterflies, all very tatty and worn: perhaps they had been blown across the Channel from France on the warm southerly wind that is accompanying this anticyclone (centred to the east). Nearby were a few Brown Argus, small butterflies in the Blue family: not uncommon in France, far from common in England. Their coloration may seem odd for the Blue family, but females of quite a few species are brown, contrasting with their bright blue males, so the genes for ‘brown’ are clearly available: perhaps it takes just one or a few genetic switches to turn on brownness in both sexes rather than in just one.

In several places on the hill, often on bare chalk paths or short grass, we saw the glowing blue and purplish blue of Adonis Blue butterflies, with their chequered wing borders. So we saw some rather special butterflies, though with the definite feeling that they are only just hanging on in the area.

Milkwort, once a common plant in (cow) meadows
Milkwort, once a common plant in (cow) meadows

The hill is also host to Chalk Fragrant Orchid, Pyramidal Orchid, Spotted Orchid and more: it was lovely to see them all, though we were moved on swiftly by an anxious pair of Skylarks circling rather low overhead, trying to get back down to their nest, clearly not far from where we were sitting. All around in the thorn bushes were Tree Pipits, singing away, with some twittering Goldfinches and one Yellowhammer, my first of the year: yet another species that was once commonplace in every hedge.

 

Conservation, Natural History, Nature Reserves, Wetlands

Demoiselles and Warblers beautiful at Wraysbury Lakes

Banded Demoiselle Female with Half-Open Wings
Banded Demoiselle Female with Half-Open Wings

I had a beautiful, peaceful, sunny summer walk down at Wraysbury Lakes. Away from the roar of the traffic and the enormous queues brought on by roadworks and summer weekend commuting, I was surrounded by fluttering, glittering, shimmering Banded Demoiselle males, and on the vegetation also the gloriously iridescent green females, their clear green wings like fine lace dress trimmings to accompany their dazzling emerald-jewelled and enamelled bodies.

Common Blue damselfly pair in cop
Common Blue damselfly pair in cop

As well, Common Blue damselflies basked in the sun; a few pairs in cop carried out their incredibly complicated sex act, all claspers (male tail to female neck, female tail to male belly with its spermatophore and secondary sexual organs, forming the startling ‘heart’ or ‘wheel’, in which the pair can, at a pinch, fly like synchronised swimmers.

At first I thought there were no warblers about, but gradually little bursts of song punctuated the afternoon, and by the end I had heard six warbler species, and good binocular views of three of them (Garden Warbler, Whitethroat and Willow Warbler).

There were some handsome Ichneumons about, but perhaps the insect I was most surprised to see was a Small Tortoiseshell butterfly. When I was a boy these were so common as to be unremarkable – as were House Sparrows, Starlings and Yellowhammers. It is almost a shock to discover that seeing just one is now a rare treat: more nostalgic than pleasurable, perhaps.  Much work needs to be done on landscape-scale and farmland conservation to bring back our common butterflies.

 

Conservation, Natural History, Nature Reserves

Flaming June

Large Red Damselfly
Large Red Damselfly

After all the rainy weather  (I even found a large toadstool – in June: The Blusher, Amanita rubescens), today was suddenly hot, at least it seemed so while digging brambles out of the ramp meadow, raking up the scythed Cow Parsley in the full sun, pitchforking it into a barrow and carting it off to a deadhedge. It was a satisfying conservation job, one of those where you can see what you have done, and it looks a lot better after than before. The area is supposed to be a meadow; we successfully suppressed the overgrowth of brambles two years ago, leading to a burst of rather nice Garlic Mustard and its attendant Orange Tip butterflies last year: and a second wave of Cow Parsley that must have seeded itself really well, because it suddenly covered the area this year. Now that it’s all cut, we may hope that grasses and smaller herbs may get going: some Ground Elder at least has begun the process.

In the pond and on the vegetation for a way around it, including atop the hump, Large Red Damselflies are soaking up the sunshine, and flying in cop, egglaying – the females dip the rear half of their very long abdomens in the water to reach an aquatic plant such as Myriophyllum on which they place the eggs.

The butterfly transect was again quiet, but graced by the first Cinnabar Moth of the year: there is a fair bit of Ragwort coming up, and this adult must be newly hatched out of a pupa, presumably at ground level or below as the plants are annual.

Sure enough, after I had finished the transect, the first Holly Blue butterfly of the year, beautifully fresh and new, skipped its bright quick flight just in front of the hut.

Conservation, Environment, Gardening

London Orchard Project’s 5th Birthday Party, in City Hall

City Hall and the Shard
City Hall and the Shard

In the evening I went down to Tower Hill and walked across Tower Bridge to City Hall, where the London Orchard Project was celebrating its 5th Birthday.

The City and The Tower of London: 1000 years of growth
The City and The Tower of London: 1000 years of growth

The amount of new development is a shock after the relative quiet of west London, but I had a strong feeling (presumably the City Hall architect’s intention) of being right at the centre of a great and bustling city.  Across the river is the quiet symmetry and antique military splendour of the Tower of London: it’s even beautiful in its stern way. But right next to it is the bulging, up-thrusting, grey glass, steel and concrete disharmony of the City, former giants like the NatWest tower and the Gherkin already dwarfed by newer demonstrations of financial might, brazenly shoving their manhood  up into the sky. It’s jarring.

But then, I reflected, there are Roman walls near the Tower and at the Barbican: this city is 2000 years old. It was already ancient when the Normans came and rudely shoved the White Tower with its four-square pinnacles and Might Makes Right foreign invaders’ pennants to fly high over a thoroughly defeated, despondent and disgusted Anglo-Saxon (i.e. English) nation.

Little Red Riding Hood (symbol of Idunn, goddess of Apples and fertility) would have been proud of the baskets of bright red donated fruit
Little Red Riding Hood (symbol of Idunn, goddess of Apples and fertility) would have been proud of the baskets of bright red donated fruit (image not enhanced)

Once inside City Hall, after the brisk initiation with airport-style security (at least I didn’t have to remove shoes and belt), it was down and round the ridiculously long spiral ramp – what a grotesque waste of space compared to stairs and lifts, but how distinctive also (presumably city politics takes you round and round and never seems to get anywhere, hmm), I stumbled into a meeting room decked out with fruity bunting, maps, photographs, fruit juice, cider, apples, apple cake and bowls of dried fruit and nuts.

Some of the Project's Apple Juice to try
Some of the Project’s Apple Juice to try

I learnt that London Orchard Project had been founded by two friends, Carina and Rowena, who had just realized that our parks didn’t have to consist of nothing but inedible London Plane trees and grass. They emailed a lot of people and within four days had 120 groups who wanted to join in! Since then, 12 old overgrown orchards have been saved and restored, and an extraordinary 83 new orchards have been planted all over our city: soon there will be 100. Even after 2000 years of urban growth and development, I reflected, there is still space and energy and enthusiasm and collegiality for a hundred beautiful spaces full of healthy, vigorous,  productive fruit trees.

Carina, Rowena, Lewis and Amber cutting the cake ... with a fiercely serrated pruning saw
Rowena, Kath, Carina, Merrin, Lewis and Amber cutting the cake … with a fiercely serrated pruning saw

All the talks were remarkably interesting. Lewis McNeill gave practical tips for healthy fruit trees, from pruning to fertilising, and gave away root cuttings of Comfrey, a herb which grows vigorously and gathers minerals in its leaves, making it ideal as a mulch for Apple trees. London Glider cider-makers described their first few years, going from newbies to experts: unlike beer, which you make, sell, and then do the next batch, cider is made in the autumn, sold in the spring so you need a lot of storage: they do 7,000 litres a year, the limit before paying excise duty on every litre.

Amber Alferoff, a project manager (she’s on the right of the photo) spoke on the folklore of apples – all those fertility goddesses like Astarte/Ishtar, Aphrodite, Freya, Idunn and the Roman goddess Pomona (that was an easy one) have names that mean Apple, apparently, while Adam and Eve are offered the Apple by the Snake/Dragon, a combination that goes right back to ancient Babylon long before the bible, apparently.

London Orchard Project founders Rowena and Carina cut the birthday cake
London Orchard Project founders Carina and Rowena cut the birthday cake

Carina and Rowena joined the celebrations by cutting the cake with a viciously sharp doubly-serrated 70-cm pruning saw (and the obligatory hard hat for tree work). There are 1200 volunteers; hundreds of Orchard Leaders; 50 public events; 3 tons of apples; a new apple variety, “Core Blimey”; and they even met the Queen. They worked fulltime for the project for a while but have now taken a well-deserved back seat as trustees.

In the driving seat now is Kath Rosen, Chief Executive, who spoke energetically about progress and the future, which most immediately is to start work in other cities including Manchester. That means the project has to be renamed to the Urban Orchard Project, as it’s no longer just London: growth indeed.

And Rich Sylvester, wearing quite a hat, told stories and made us sing an adapted version of ‘I’ve been a Wild Rover / For many a year’ only it was all about orchards.

But for me the most inspiring talk of the evening was given by the community team from the Orchard Estate in West Greenwich. The photographs told the story: a bleak estate of tall ugly brick-and-concrete towers surrounded by blank areas of grey concrete and dustbins. The residents never spoke to each other. Then in 2012 with the Olympics, money was on offer for a dozen projects, just a proposal was needed. They had a go and won: now there’s an outdoor gym area, popular with all ages; a large square of grass dotted with neatly mulched circles around handsome apple trees; and a veggie polytunnel and a dozen allotment plots, where neighbours come out to sit, chat and enjoy working together. The effect on wellbeing and genuine community (what an overused word that is) was immediate. Now the London Orchard Project has got them to act as tree nursery for the whole project, as they have enough land for it, and willing people too.  When they said that now they were extending the orchard with more trees every year in a new area of the estate, there was cheerful and rightly appreciative applause. We learnt, too, that visits to other orchards were always enjoyable, always a time to learn more. The name “Orchard Estate” had come, by the way, from a real orchard that the concrete had destroyed, the architect soullessly naming each hideous tower after a kind of apple – Worcester Pearmain, Egremont Russet and so on. Now, full circle, a tree of each of those varieties has been planted: all but one, now uncommon, which is being sought. Life goes on, and together, if we work as a community, we really can be in harmony with nature and each other.

 

Conservation, Natural History, Nature Reserves

Swifts Screaming High Over the Cow Parsley at Gunnersbury Triangle

On a grey rainy day, I put on my waterproofs and go down to the Gunnersbury Triangle reserve. A newly-fledged Green Woodpecker flies off. The cow parsley has taken over the whole of the meadow by the approach ramp; last year there really wasn’t very much of it, but now the tall white umbels are quickly turning to seed-heads across the whole area: they need to be pulled up quickly before they ripen. They are accompanied by quite a lot of cleavers (sticky-grass), nettles, hogweed, even hops twining their tall fibrous way over the other plants. And a few brambles are coming up again: we had a blitz a year or two ago, pulling out most of them, and the meadow is much improved, but that hasn’t saved the rather nice garlic mustard (good for orange tip butterflies) from the cow parsley invasion.

I loosen one bunch of roots after another with a fork, and pull up the cow parsley roots – much like carrots, they’re in the same family. When the soil is shaken off they are a pale brown, some straight and carroty, some branched into five smaller swollen roots. When I have a big armful, I carry them down to the dead-hedge.

Digging again, a nettle manages to sting me lightly through the leather-and-cloth gardening gloves. I hear a screaming sound and look up: eleven swifts are wheeling together high overhead, the most I’ve seen over this part of town this year, indeed for many a long while. Sixty or more sometimes gather over the lakes at the London Wetland Centre, pausing to feed before moving on up north on their spring migration.

I gather another armful of cow parsley. The meadow is starting to look a little better. I pull a six-foot stick out of the herbage; half-a-dozen diversely coloured white-lipped land snails, some plain yellow, some striped with black, fall out on to the path. The polymorphism has been argued over by ecologists: it might be camouflage adapted to different backgrounds, some lighter, some darker; or more interestingly, it might be a way of defeating predators like Song Thrushes which could be searching for snails of a particular pattern, so if a bird had learnt that snails were striped and had that ‘search image’, that bird might not spot plain snails, perhaps.

It comes on to rain. I help out in the hut, making preparations for Bug Day when we hope the reserve will be buzzing with excited children and their parents. They will be welcomed by a smiling ‘GunnersBee’, who is a black-and-yellow cutout on a huge blue card with yellow cutout flowers. Even in the drizzle, several species of real bumblebees are busy gathering pollen and nectar.

Conservation, Environment, Love of Nature, Philosophy

Love of Nature? Man vs Nature? How Very Odd

There is something distinctly odd about the British love of nature. I mentioned the subject at a book launch the other day, and the person I was chatting to said, between sips of the very nice white wine and a nibble of the focaccia, that he thought the British were not really in love with nature any more as a personal activity, but were just consumers, passively and vicariously absorbing what is offered up as a commodity. I said that was ‘interesting’.

The ‘in love’ view of the British perhaps blends several different stereotypes. One is the obsolete stiff upper lip, the naturalist out in some far outpost of forgotten empire, enthusiastically carrying on studying phasmids like James Wood-Mason, writing obscure papers in the Journal of the Asiatic Society of Bengal for the benefit of anyone of similar inclination.

Another is the hugely enthusiastic amateur naturalist – the keen birdwatcher, entomologist or botanist with telescope, moth-trap or vasculum always to hand, hoping to add a species or two to a county list.

Yet another is the happy gardener, always outside – rain or shine – pruning, digging, composting, planting, watering, weeding.

The stereotype that my wine-sipping acquaintance had in mind was presumably rather different: couch potatoes, relaxing with a remote in the sitting-room, allowing an hour of television gardening with Monty Don or a year in the life of some wildlife area – the Canadian Rockies or the Great Barrier Reef, the Patagonian plains or the last surviving bit of the Sundarbans, or worse, all of the above, cut together by an editorial team with a high concept of Surviving Against All the Odds or something – to wash over their minds, leaving no particular trace other than a feeling of having seen a lot of colourful flickering images.

Personally, I doubt that picture is fair, though like all stereotypes it must make some contact with reality somewhere. People are all different, and everyone needs to relax sometimes.

A truth, though, that everyone who likes some kind of experience of nature, live or through book, film, photograph or website, is that if we’re studying or watching nature without doing something to help protect it, we are ignoring a very large existential threat indeed. Assuming we manage not to destroy ourselves in a nuclear war, we are going to have to work out how to survive an ecological disaster of our own making. Its epic proportions are becoming clear: the last time anything like this happened was at the end of the Cretaceous period 66 million years ago. Whether Luis Alvarez was right that an asteroid or comet crashed into the Earth to form the Chicxulub crater, the debris thrown into the atmosphere causing something like a nuclear winter, it is certainly the case that huge numbers of species became extinct very quickly, including all the world’s large dinosaurs (yes, I know we have the birds still with us, and they’re in the dinosaur clade) along with perhaps three quarters of all other kinds of living thing.

You may perhaps feel somewhat untroubled by the idea that the world of your grandchildren might have no tigers or rhinoceroses in it; or even that there would be no areas of rainforest outside national parks – the Amazon and the forests of Sumatra and Borneo are well on the way there already.

You might be slightly less thrilled at the news that many of the world’s hotspots for variety of animals and plants will be gone completely: as South Africa becomes warmer and drier, the whole Cape region as understood by botanists will move southwards – into the ocean – and disappear forever, that incredible wealth of flowers, all those extraordinary Proteas, will remain only as a memory.

Perhaps even that isn’t too worrying, just news from a far country? Well, the sea level will rise by several metres when the Antarctic ice-cap melts, flooding coastal plains and threatening to drown many cities.

Not a problem? Global warming, whatever may have caused it, is already making deserts expand. Droughts will become year-long from California to southern Spain, Sahel to Australia. Food prices will rise drastically; wars will be fought over water and other critical resources.

Still not your problem? Farmland all across America and Europe is already denuded of crop pollinators, especially honeybees and bumblebees. Grasses like wheat and rice are not affected, but much of your food, and vital fodder crops for farm animals – from alfalfa to zucchini – is utterly dependent on pollination, and it’s in free fall.

What is all this about? How have we got into the crazy situation that half of us – some of us anyway – love the idea of nature, love to look at it (at least the pretty bits), while the rest (ok, possibly nearly everyone, whether we like nature or not) see themselves as separate from it? How separate can we be when we depend on it absolutely for the air we breathe – all the oxygen produced by green plants – and the food we eat – all our food coming from animals and plants? What are all those student notes in English literature about ‘man v nature’? We are part of nature. It isn’t even that nature is our survival blanket. We, like all other living things, are part of an ecosystem. The mosquitoes that bite you on holiday are in no doubt that you are edible. You eat chickens or carrots, beef or beans. Billions of bacteria in your gut share that food with you, consuming some, helping you absorb the rest. Eventually, bacteria will consume you, if you don’t get yourself cremated first. You are part of nature, no doubt about it.

So, how are you going to change what you do, to help keep this system working? Right now, it’s already badly broken, and getting worse each year. We haven’t got long to fix it.

Conservation, Environment

The Unchanging Woods, Maybe

You enter the wood — and you might just as well be in the Middle Ages. When I hear people speak of the Dark Ages, I remind myself how in those days the sun shone in just the same way as it does now, and the flowers glittered in woods where there was no difference from what we see today. … Inside the wood we are in the past as well as in the present.

With these thoughts, John Stewart Collis draws his book Down to Earth, now the second part of the combined volume The Worm Forgives the Plough (see my book review) to a close.

And in a way his thoughts from 1947 are still true today: nature is timeless, specially in a wood.

But in another way, the woods of 2014 are very different from those of 1947. The old practice of coppicing is all but dead: a few nature reserves struggle to practise something approaching it; enlightened landowners fell woods in patches rather than clear-felling whole landscapes, approximating the mosaic of new glades, fine old trees, brushwood, young trees and woodland edges bursting with songbirds that characterise true coppice. Often, in the old way of things, coppicing deliberately left behind a few ‘standards’ here and there, fine straight oaks or other hardwoods to grow large timbers for building ships or roof beams. Now, woods are more likely to be managed industrially for timber, or are sadly neglected with ivy on every trunk, brambles all around the forest floor.

Reeves' Muntjac, introduced from China, are now widespread across Britain and Europe
Reeves’ Muntjac, introduced from China, are now widespread across Britain and Europe

And it gets worse. Where Collis took for granted that woods in springtime saw the primrose, then the bluebell, with here and there an orchid, our wild flowers have declined markedly for reasons to do with human interference. Visitors from the cities pick nice-looking flowers, or dig them up to plant in their gardens. Accidental introductions of deer, especially the Muntjac, graze native flowers down to nothing. Many flowers listed in field guides as common are becoming hard to find outside nature reserves.

Numbers of deer in general, including our native Roe and Fallow, are increasing (and they are spreading into the suburbs) as gamekeeping declines. Since all our large native predators like bear, wolf, lynx, wolverine have long ago been hunted to extinction, there is nothing but human hunting to control deer numbers, and current levels of hunting are insufficient. Maybe George Monbiot is right: our woods need rewilding.

 

Conservation, Environment, Natural History, Nature Reserves

Gypsy Moth plague

The Gypsy Moth, Lymantria dispar, is  a notifiable pest listed by DEFRA, or at least it was when that document was published back in 1997. The insect was announced to be “a serious pest of trees and shrubs” and nurserymen and landholders were required to notify DEFRA or the PHSI HQ immediately.

Gypsy Moth caterpillar on birch trunk
Gypsy Moth caterpillar on birch trunk: blue warts at front, red warts at back. The black-and-white pattern may also be aposematic

It has arrived in the Gunnersbury Triangle with the hairy dark caterpillar larvae with blue and red warts on their backs all over some Birch trees. The infestation is rapidly defoliating them, and causing substantial damage to some Oaks too.

Lymantria means ‘destroyer’, quite a well-named genus. The caterpillars are aposematic, their hairs and bright coloration warning off predators; the hairs are irritant, containing diterpenes, complex organic ring compounds found in wood and plant resins for defence against microbes and fungi, and retained by the caterpillars for defence against predators.

It will be interesting to see how the trees cope. Oaks can generally recover even when thoroughly defoliated; the Birches may suffer more. People can hardly use pesticides in the nature reserve, even given the means to spray whole trees safely, but biological controls are imaginable. The caterpillars are parasitised by Ichneumon flies, which may well be keeping Gypsy Moths under some sort of control in Europe. There were no controls in place to halt the spread of Gypsy Moth in America, however, where the pest was accidentally introduced in 1869 from Europe by the amateur entomologist Étienne Léopold Trouvelot. He was hoping to cross-breed them with silkworms to improve their disease resistance; he is remembered instead for starting a disastrous continent-wide caterpillar plague which still continues. Attempts with other pest species to introduce their predators or parasites have often proved unsuccessful and sometimes disastrous in their turn.

Conservation, Natural History, Nature Reserves

Giant Ichneumon in London Reserve

A terrifying monster stalks the suburbs. Silently and with unerring accuracy, it scans the surface, using its advanced sensors to detect and identify targets buried deep below. Once a target has been located, the hunter drills down to find it, deposits the payload, and leaves in search of the next. It could be a cyber-borg or pilotless military vehicle. Actually, it’s Rhyssa persuasoria, the giant Ichneumon. And giant or not, it’s about 30mm long.

Rhyssa persuasoria, side view
Rhyssa persuasoria, side view

Rhyssa is a parasitic wasp, a solitary hunter distantly related to the social, black-and-yellow striped wasps. Her prey are the larvae of other insects which burrow in dead wood for food and safety. Only when she is above, safety below is hard to find. For Rhyssa‘s weapon is as long as her body: her ovipositor is greatly elongated into a precision instrument that can drill deeply through wood and into the body of the larva. Once there, she lays a single egg down the ovipositor tube. The egg hatches inside the still-living larva, and devours it from the inside. The larva dies (so Rhyssa is a parasitoid, not a true parasite that avoids killing its host) and a young Ichneumon emerges.

Rhyssa persuasoria dorsal view
Rhyssa persuasoria, dorsal view: in search of a host

Today at Gunnersbury Triangle we erected a new bench, to allow visitors to relax and enjoy a quiet moment in nature. It sounds a trivial task. If only. Two volunteers spent a day putting the “ready to assemble” kits together. All the supplied bolts were the wrong size, so they had to ream out all the pre-drilled holes to the larger size. Meanwhile, that day, I dug out the well-embedded MetPosts remaining from a previous bench. Then we dug 2 holes for the new bench: they promptly filled up with water, and the deeper we dug, the more the local weakly-cemented gravel (our local rock, when it isn’t sticky clay) collapsed into the hole, making it wider at the bottom. It was clearly hopeless.

So today we spent an hour prospecting for a drier place that would also be aesthetically pleasing, not harm the rare ferns nor disturb the nesting Blackcaps, and be close to an existing path. Then we started digging holes all over again. This time they didn’t fill up with water, much: just the bottom 10 cm or so. To keep the sides from crumbling, we avoided digging with spades: we lay on bin-bags, and wearing rubberised gardening gloves, scooped out handfuls of wet gravel. Then we levelled the two holes, cast a base of PostCrete in each, let it cure — at this point everybody disappeared for a cup of tea, leaving me in the wood guarding the site. I sat on a coppiced Willow trunk, and was approached by the giant Ichneumon when I least expected it. Luckily my little camera was not far away — you can readily imagine why I wouldn’t want the big camera with me while working.

The team reassembled, we gingerly lowered the bolted wooden creation into place, wedged it tight with broken bricks, and fixed it in place with plentiful PostCrete before cunningly sloping the top to shed rainwater. Needless to say, during this procedure we accumulated more and more tools all round the excavation site. If only it were as simple as drilling for an unseen caterpillar and laying an egg in it. But then, Rhyssa has the jump on us, with millions of years of evolution in her hunting technique.