Blog Archives: WildWivenhoe

Our new toy – a compact portable moth trap

Living in a top floor flat has many advantages – the light, the views, the health benefits of 53 stairs to climb – but it isn’t really compatible with regular moth-trapping. Lack of space means our large Robinson trap is now relegated to the loft space, emerging only on special occasions, and those are restricted to times when we have access to mains electricity or a generator.

A chance meeting in Cambridge Botanic Garden alerted us to new style, truly portable LED traps now available from our friends at Anglian Lepidopterist Supplies. Run off a rechargeable small battery pack, LEDs have been sourced which emit strongly in the UV light spectrum, the frequencies which many moths respond strongly to. This helped overcome our scepticism about LED traps, and we decided to invest.

The trap has now had four outings, so time for a review. Our expectations were managed at the outset with the suggestion it was likely to be most effective in very dark conditions, so we had no high hopes when we ran it in a friend’s urban garden with skyglow, only 10m away, but shaded from, his 125W MV trap light. It was good to see the light still on first thing – the battery had performed to expectations – but compared with the adjacent MV, fewer free-range moths outside the trap. However once inside, it was a very pleasant surprise to find a goodly proportion of the species from the big trap, including a Privet Hawk, three Elephant Hawks, Scarce Footmen, Least Carpets and Brown-tails,

Apart from the greater number, the only things in the big trap which turned us appropriately green with envy was a Green Silver-lines and an L-album Wainscot, and we had several species not in the big one, including Bright-line Brown-eye, Iron Prominent and Latticed Heath, together with the distinctive nose-down micro Pediasia aridella and a Sexton-beetle.

Second outing was close to the Wivenhoe Barrier, overlooking salt-marshes, a generally dark zone but again with distracting intrusion from security lights. Almost instantly the LEDs attracted hundreds of Water Veneers, a short-lived whitish micromoth which emerges in a coordinated way to maximise the chance of meeting and breeding.  Ruby Tiger, Yellow Shell, Diamond-back, Cloaked Minor and Dingy Footman also popped in, along with the mayfly Cloeon dipterum, several caddisflies, and from an entirely different habitat, a Nut Weevil.

Two nights’ later in the same locality, it was a rather different picture. A little cooler, a little breezier, a more lingering twilight, and no emergence of Water Veneers. But again a few moths came in the hour or so of dark we were there, mostly LBJ micros (many being Bryotropha species) with only one different macro, a Rosy Rustic.

Finally, a truly dark location, Wivenhoe Old Cemetery, an old Victorian graveyard which has grown up into woodland, where trapping sadly terminated a bit early because of rain. The attraction was instant, the diversity reasonable, including several Orange Swifts and Straw Underwings, together with micros such as Nephopterix angustella (still considered to be an Essex Red Data species, despite recent increases) and Mint Moth, and the usual variety of hangers’-on, including caddis-flies, Nut Weevils and damsel-bug nymphs.

In a nutshell, this LED trap will never supersede an MV trap for numbers (of individuals or species), but not everyone has the time to process five hundred or more moths in the morning. But with the phasing out of mercury, MV bulbs are on the way out. And the portability (and flatpack storage) of the LED trap means that is likely to be the future of mothing for us.

 

The Beth Chatto Gardens throughout the seasons: August

High summer, those languid, lazy days of sunshine and leisure…if you are human. But for the rest of the world, a time of frantic activity, flowering, seeding, feeding and breeding. Many of the flowers are fading, evidence their job is done, though some like Echinacea and Asters reserve their finest show for the later months, just as the throngs of insects need it the most.

And what a range of insects and other invertebrates, from butterflies and bugs to micromoths and flies, with as always spiders taking their share:

But  wear and tear on leaves is also a positive sign, indicative of the feeding activity of those mobile garden adornments which will bring movement, excitement and joy to next year’s borders.

Down by the water’s edge, summer was only just bursting, with swathes of colour, and flashes of magic from dragonflies and damselflies.

But all was not as serene as it seemed. Large clumps of flowering Thalia dealbata in the ponds were clearly a magnet for insects of all sorts, hunting nectar and pollen…

…but on closer examination, each flowerhead was riddled with corpses – hoverflies, lacewings, bees, wasps and blow flies – a mortuary for those valuable garden assistants, pollinators and predators alike, all stuck headfirst into the mouths of their nemesis.

The scale of the carnage, was quite simply shocking. Some, still alive, like this Honeybee we managed to release, but most were dead. Lost to the world.

Reference to the internet shows this is a recognised phenomenon. The plant has no reason to kill its visitors – it doesn’t digest them like a truly carnivorous species: it seems that the flowers have an elastic style, used in explosive pollination which can and does trap insects In its native central American range it is normally pollinated by large and powerful Carpenter Bees, capable of extricating themselves from the flower’s fatal embrace. Anything smaller, mere collateral damage, cannon fodder in the battle for life.

But at times of an Extinction Crisis, that is one pressure our array of pollinators, necessary not just for the plants but for our species’ continued existence, can do without, dozens of pollinator lives extinguished unnecessarily for each flowerhead. The Beth Chatto online sales catalogue does at least draw attention to this antisocial behaviour of Thalia, but none of the other websites I have visited, nor the RHS make any reference to it. Time for a campaign, maybe a ban, but at least removal of the flowering spikes before they open. It’s not as if they are especially attractive, the main value of the plant being its architectural emergent foliage.

On a happier note to end with, one of the great advantages of being naturalists is that people bring us specimens. And so it was today when a proffered pot revealed its treasure, a Tanner Beetle Prionus coriarius that the Education Team had just found, something that neither of us had seen before.  A large, blackish longhorn, it is considered to be rather rare in Britain, found at scattered localities in the south of the country, and is usually associated with ancient woodland or extensive natural landscapes like the New Forest. Its larvae, like those of Stag Beetles, develop over several years inside rotting wood, and the National Biodiversity Network map shows one previous record close to Elmstead Market, but very few others in and to the east of Colchester.

 

 

#WildWivenhoe Botany & Bug walks: August – The Shipyard and Barrier Marsh at dusk

We decided to try something new this month – the long warm nights seemed too good an opportunity to miss –  so we spent two very enjoyable evenings with some of you local nature-fans enjoying the beauty that is Wivenhoe, with some wildlife thrown in!

The jetty is a wonderful spot for admiring the river, the salt marshes and the big Essex sky.  Looking heavenwards on Saturday we were privileged to witness a ‘Sun dog’.  This phenomenon only occurs when the time of day, year, and weather conditions are just so.  Sun dogs come about when the “22 degree halo round the sun intersects with the parhelic circle centred on a point directly the observer” (phew!) and are manifested as two fleeting bright spots like rainbows, either side of the sun.  And like rainbows we all see our ‘own’ version of them, directly in line with our visual gaze.

Monday evening was different,  a more traditional cloud- and water-scape sunset, but those who were waiting on the jetty a few moments before we started were lucky enough to hear and see a Kingfisher, quite unusual for this time of year, although a frequent visitor to the dock in the winter months.

We  discussed the history of the river, and the various benefits/ disadvantages of the barrier.  Of course, it keeps Wivenhoe and much of Colchester safe from flooding  (a distinct benefit!), but at the cost of altering river flows. Along with the cessation of dredging now the upstream ports have closed, this means silt is building up.  This in itself is not all bad news of course – the accretion of mud is allowing salt marsh plants to become established.

Some, like Sea Aster, are useful nectar sources; others such as Marsh Samphire are edible for us humans (though possibly being so near the sewage works at the Hythe makes that a  less-than-appetising prospect!). Sea-purslane is noteworthy, being its own desalination plant – it takes in salt water and excretes crystals of salt from its leaves.

Common Cord-grass has an interesting provenance, being a hybrid of two types of cord-grass, one native and one from America, but unlike most hybrids which are generally infertile has now become able to reproduce by seed and as a consequence is spreading.  At present it is not a problem here in Wivenhoe, but its aggressive growth, at the expense of native plants, is proving troublesome on some salt marshes.

The two-leaved form of the Four-leaved Allseed is a small and unprepossessing plant, but very rare and grows for unknown reasons along patches of Walter Radcliffe Road.  This is despite the best efforts of Trinity Estates to eradicate it  (along with anything else that has the audacity to try to grow along our roadsides) with highly toxic chemicals.  This plant used to be known only in the far south-west of England, but recently been spotted along the Thames Embankment and has now arrived at Wivenhoe.  On boots, boats or car tyres?  We shall never know.

The seawall beyond the Sailing Club is well stocked with plants particularly suited for the salty conditions – including Strawberry Clover and Dittander – which bring some welcome colour and of course food for insects.

On Barrier Marsh itself are myriads of anthills, some very ancient, a good indicator of unploughed and infrequently inundated marshland.  Though we well remember December 2013 when due to the ‘perfect storm’ conditions of low pressure and spring tide, the sea wall was overtopped – here’s a flashback, and perhaps a vision of the future:

A walk across the marsh did not unfortunately bring forth any Glow-worms on either evening but the presence of three species of bat was picked up thanks to our clever detector.  This ‘Batscanner’ automatically switches to whichever frequency is being emitted by any passing bat – each species uses a unique frequency to ‘echolocate’, so if you can find out one you can work out the other.  On Saturday two species of Pipistrelle were picked up, and on Monday the larger, more uncommon Serotine.

Talking of new toys, these evenings  were opportunities  for us to try out our new battery-operated portable LED moth trap.  Not having being road-tested before, we were delighted how far that little candle threw his beams, attracting several species of those most mysterious of nocturnal creatures.  On Saturday a huge number, hundreds in fact,  of tiny white Water Veneer moths, appeared.  These have a very short adult life-span, sometimes only hours, so we were glad to provide an opportunity for lots of them to ‘get together’ to do what moths do, and hopefully when we turned the light off at 10.30 they all had the opportunity to fly off and lay their resultant eggs (the females anyway!).

Other moths that paid us a visit included Ruby Tiger, Dingy Footman (dubbed by one of our group as the ‘Pumpkin seed moth’), Cloaked Minor, Yellow Shell, Maple Prominent and Garden Carpet. Don’t they have brilliant English names?  Of course they all have their Latinised scientific names too, but generally moth-ers only refer to the tiny micromoths, which do not have catchy common names, by these.

But there are exceptions: Water Veneers have already been mentioned, while the Diamond-back Moth, of which a couple dropped in, deserve a common name by virtue of their distinctive markings and habit of arriving on our shores after migrating from the Continent on wings only 8mm long.

Other creatures popped in to say hello too, attracted by the light – Harlequin Ladybird, caddisflies, a  mayfly and a cute Nut Weevil.   Once everyone had had the chance to have a look, all were released and allowed to carry on their nocturnal business unharmed and undetained.

It was surprising how the difference in conditions (more breeze, less cloud cover resulting in a lighter evening) made the mothing less productive on Monday.  Interestingly there was not one Water Veneer, supporting the theory that these, and many other creatures, all emerge at precisely the same time.  After all, it is no good hoping to mate if there is no one else around to mate with!  A few tiny micromoths fluttered in and out, but the main catch of that evening was a Rosy Rustic.

All photos in this report are our own, but other than the moths and sunsets, most were not actually taken on the nights in question, due to poor light conditions.  We hope that everyone who came along enjoyed this venture into the unknown!

The Beth Chatto Garden throughout the seasons: July

It’s a garden, so yes there were flowers. Spectacular blooms, interesting forms, a multicultural mix of plants from over much of the world.

But it wasn’t the flowers themselves which grabbed our attention this time. It was the insects, burgeoning biodiversity benefitting from the floral resources, and repaying the debt with pollination and pest control, sprinkling the garden with stardust for anyone with an eye to see and appreciate them. No names here; indeed, we don’t even know some of them. But names are not the point: what is important is that they are here, delighting us, inspiring us, and doing their jobs.

This unpaid army of garden workers, not just bumblebees and honeybees, but solitary bees and wasps, sawflies, beetles, lacewings and a whole lot more are all too easily overlooked and ignored. And abused.

 

So it is good to hear that there are changes underway in the garden management phlosophy and practice at Beth Chatto’s. A trend away from over-tidiness and manicuring. No more slug pellets. Progressive reduction in the use of sprays, those poisons which now drench our world and threaten its life-blood. Step by step, every step of the way is one more step on the road to a sustainable future. All it needs is a more relaxed mindset: there may be some holes in the Hostas, shredding of the Solomon’s–seal,  but think of those as natural art installations, a badge of honour instead of a sign of ungardenerliness….

Would Beth have approved? Maybe, maybe not. She did of course come from a very different gardening era, when perhaps it seemed that it didn’t much matter what was done in the garden because there was abundant wildlife out there in the countryside. But no longer: as the wild world outside has become more and more depauperate, so have gardens assumed an increasing role as a haven for the little things that make the world go round. So thank you Beth Chatto Garden for moving with the times, and stepping up into your role as inspiration for gardens of the future.

 

 

 

#WildWivenhoe Botany & Bug walks: July – the wild side of Wivenhoe town

This month’s Walks on the Wild Side were explorations of some of our town’s amenities, which are there on the face of it for us humans to use and benefit from.  However, thanks to now-sympathetic management from Wivenhoe Town Council, each of these is enhanced by the proliferation of wildlife that has been allowed to move in, bringing enjoyment to anyone who takes the time to stand and look.

First up, the Old Cemetery in Belle Vue Road.  This ancient burial ground had for years benefitted from adherence to a Management Plan which prescribed mowing half of it in alternate years, which kept the vegetation under control whilst allowing refuges for over-wintering insects.  Until, however, a few years ago when incredibly the decision was taken to destroy the rhythm of the place and clear the lot in one fell swoop.  Bare and barren,  Mother Nature responded with vigour, and while still not properly back in rotation, in time, assuming the agreed plan is adhered to, this will return to the peaceful and beautifully untidy place that most of us love.

What did we see?  Well some insects are certainly more in your face than others!.  Butterflies were showing off, whizzing around in the warmth – several species of ‘Browns’ (Speckled Wood, Meadow Brown, Gatekeeper, Ringlet), plus Small White and various Skippers.

Damselflies darted about and grasshoppers and Speckled Bush-crickets hopped out of our way as we walked around.  Our old favourites the Hogweed Bonking-beetle and Thick-thighed beetle were hanging about in various poses on a multitude of flowers.  The Bramble, a plant which soon takes over if unchecked, is at this time of year a very valuable source of nectar and was veritably humming with bees and hoverflies.

Some insects, however, are more secretive and can only be noticed by careful searching.  The weeny Virgin Bagworm moth spends its whole life in a little lichen-covered silken bag wedged into minute places –  the carvings on gravestones are ideal for their purpose.

A close inspection of tree trunks revealed a number of delights – a robber-fly tucking into his crane-fly lunch, a splendid plant-hopper Allygus mixtus, a fabulous little moth Dasycera oliviella, plus rather weirdly a mayfly, normally associated with water

A Least Carpet moth was in full view on a nearby bush, but, by using its clever disguise as a birdpoo, was almost invisible.  We observed Mrs Nursery Web spider carefully carrying her egg sac to somewhere safe and a Great Pied Hoverfly was enjoying the sun.

Of the plants, the prettiest flower was without doubt the tiny Scarlet Pimpernel, whilst in contrast the spectacular  Himalayan Pine with its amazing cones and long, gracefully drooping needle, was a statuesque example of the splendour of nature.

Next, over the road to the New Cemetery, where it was pleasing to see a new native hedge beginning to take shape on the boundary wall, plus patches where the grass had been allowed to grow up a bit, bringing forth a multitude of flowers with their resident butterflies and other insects.

So onward to our next destination, King George’s Field and the Wildlife Garden.  The field had two interesting areas to look at.  The central ‘seam’ halfway down has this year brought forth a couple of nationally scarce clovers.  Possibly due to last year’s severe drought, the bare scorched ground allowed the seeds of these plants to take hold.  Were they already in the soil, just waiting for the conditions to be right to allow germination, or did they arrive on someone’s boot?  We will never know.

Anyone visiting the field this summer, or last year, will have noticed the patch of ‘hay-meadow’.  The many and varied plants here have all appeared by themselves,  having waited patiently to spring forth once the previously punishing mowing regime was relaxed.  Numerous grasses, Black Knapweed and Lady’s Bedstraw were all looking fine, and again we were treated to butterflies dancing in the sunshine and beetles and flies waiting to be discovered.  Who said flies are black and boring – this little grass-fly was very cute!

The meadow will be mown at the end of the season  and the resultant hay used to provide seeds for other wildlife areas, eg patches of St Mary’s Churchyard where a wild area is also now taking shape.

Many of you will remember ‘GardenGate’ a few years ago when the Wildlife garden, having been lovingly created by locals, was virtually ruined by overzealous mismanagement.  Fortunately the Council stepped in to try and repair their damage  – another native hedge was planted to replace the one which was ripped out, and a more relaxed regime has now been adopted.  And of course the wildlife loves it.  A Heterotoma planicornis plant bug was one of the most interesting finds there, and we were all thrilled to see a number of dragonfly exuvia on reeds in the pond.  These are the empty cases of dragonfly nymphs which they leave behind having spent their first stage of life in the water.  They then crawl out, split their skin, find somewhere to pump up their wings and turn into the aerial acrobats that we all know and love.  It all seems pretty miraculous.

A final mention must be to our old favourite, the Stag Beetle.  We saw just the one, on the ground adjacent to the Wildlife Garden as she went about her business of the day.  Wivenhoe is an important hotspot for these amazing insects and anything we can do to assist them, such as allowing a woodpile to go undisturbed in your garden, is to be commended.

Thank you all who joined us, your observations and enthusiasm, and we hope that you enjoyed it as much as we did. If anyone feels moved to congratulate Wivenhoe Town Council on is estates management, the Town Clerk can be emailed at enquiries@wivenhoe.gov.uk.

#WildWivenhoe: Burnets, butterflies, beetles and bountiful blooming at Lower Lodge

Lower Lodge keeps cropping up in these blogs – see here and here. No wonder: it is one of the most exciting places for summer wildlife in these parts, all the more exciting as much of that wildlife has moved in over the past ten years or so.

Farmed until the 1980s and now owned by Colchester Borough Council, until relatively recently it was all repeatedly mown throughout the summer. But now, as an integral part of the Colne Local Nature Reserve, the regime over substantial blocks of the site has been amended to mowing on a two or three year rotation. This is enough to control the incessant attempted colonisation by trees, and provide a rich floral mix which is a magnet for insects.

At this time of year, Hogweed stands proud from the grass heads, great horizontal plates of food – nectar and pollen – for vast numbers of flies, beetles and other insects.

Hogweed Bonking Beetles live up to their name, often multiple pairs per umbel, and with careful searching it is possible to find the deadliest of hoverfly predators, the crab spider Misumena vatia. Coming an a range of colour forms, they are likely to be most effective as hidden assassins on a background which matches their own colour closely.

Another of the valuable midsummer nectar sources is Field Scabious, attractive especially to butterflies and moths.

While the most frequent butterflies – Skippers, Meadow Browns, Ringlets and Gatekeepers – are variations on a theme of brown, some of the moths are a visual treat. Both Narrow-bordered Five-spot and Six-spot Burnets are warningly-coloured, indicating to potential predators their caterpillars may have been eating forms of Bird’s-foot-trefoil which contain the precursors for cyanide formation; those precursors can be carried through the process of metamorphosis making the moth toxic. Although I saw only Six-spots on my walk a couple of days ago, both species fly here together.

But the moth to beat them all for me is the Brassy Longhorn, which feeds as an adult on Scabious flowers, and as a caterpillar on the seeds and then the leaves of the same species. It may be tiny, but the brilliance of its metallic scales is such that it can be spotted at several metres’ range.

Very scarce in Essex (see the Essex Field Club distribution map), presumably largely due to the scarcity nowadays of grassland with Scabious in it, the presence of Brassy Longhorn here raises all sorts of questions. Particularly, how and when did it arrive? Under the former mowing regime, Scabious may have been present, but never allowed to flower, and there are very few, if any, other concentrations of Scabious locally which could have held a  relict population of the moth. As to when it arrived, having got all excited about the ‘first site record’ this year, I have just noticed that we had seen and photographed it for our 15 July blog last year, but not realised its significance!

Always more questions than answers in nature – that is one of the values of a place such as Lower Lodge, to inspire inquiry. It is a model of multifunctional green space, for recreation (both formal and informal), education, providing outdoor health benefits, and very importantly a home for wonderful wildlife. And a model which has inspired a similar relaxation of intensive mowing in other places, most notably a part of Wivenhoe’s King George V playing fields, which I will return to in future blogs.

In the meantime, just a few other images from late June at Lower Lodge: