All posts by Chris Gibson

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.

 

Standing up for Phyllis Currie Reserve – August

In the eight weeks since our last visit, the Phyllis Currie reserve has undergone a transformation – the wonderful hay meadows have bloomed and seeded, and been mown and fenced for aftermath grazing, and the hedgerows are starting to bear fruit.

But fragments of the summer bounty remain uncut, especially along the fringes, and here Knapweed, Wild Carrot and Rest-harrow were still flowering profusely and a magnet for passing pollinators and other insects.

Sadly, once again, the weather wasn’t kind to our search for insect life, being largely overcast and with a little rain, so we started off scouring the site for galls, leaf-mines and other diagnostic species’ signs. When surveying, it isn’t necessary to see all you record, provided the signs of its presence are unequivocal!

Any invertebrates we did find were sheltering, deep in the foliar gloom, making photography difficult, but included a range of bugs, flies, bush-crickets, scorpion-flies and spiders:

It was interesting to see numerous Tuning-fork Harvestmen Dicranopalpus ramosus, all horizontally-splayed legs and eponymous palps: although first found in Britain in 1970 near Clacton, we rarely see it on our home patch of north-east Essex.

Nor indeed does the attractive micromoth Metalampra italica, first recorded in Britain in 2003 in Devon, seem to have found itself in the Wivenhoe area as yet. It seems to be spreading rapidly, but the latest map from the Essex Field Club shows only five occurrences in the county,  none in the vicinity of Phyllis Currie.

Down by the water’s edge, there was more activity especially when the sun peeped out, from dragonflies, including Common & Ruddy Darters egg-laying, Emperor and Brown Hawker.  Numerous picture-winged crane-flies Ptychoptera contaminata were resting on the emergent vegetation, and – another surprise, given it is known from only a few Essex localities – the Sponge-fly Sisyra nigra. Looking for all the world like a diminutive Alder-fly, this is actually a lacewing whose larvae feed upon freshwater sponges.

The abundant flowers of Water Mint always pull in lots of insects; today it was largely hoverflies  and tachinids (parasitic flies), part of the array of unsung pollinators. And shining brightly from the foliage, Mint Leaf-beetles Chrysolina herbacea, the beetles that carry around with them their own ray of sunshine even on an otherwise dull day.

So despite the unpromising weather, this was another very satisfying couple of hours. While we may not be finding masses of rarities, the diversity of species and the abundance of insects generally is a delight. These are the little things that make the world go round, and enclaves, like Phyllis Currie,  from the agrochemical onslaught should be valued as Arks of Resilience in an hugely uncertain world.

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.

 

 

 

High summer butterflies & moths (and much else!) of the Spanish Pyrenees

Another successful Naturetrek tour to my ‘second home’, Berdún in the Spanish Pyrenees, with again the main focus being the lepidopteran delights, both by day and by night. While the number of butterfly species may have been a little lower than in previous years (see here), perhaps a legacy of the 40-degree plus inferno the week before we arrived, and the fact that we had a thundery breakdown towards the end of our stay, the abundance of many species was as high, if not higher, than in previous years. And anyway, who can complain at 105 species and counting, as the images of puzzling puddling blues, skippers and fritillaries are worked through?

As ever, the garden meadow at Casa Sarasa was heaving with butterflies – probably 25 species over the week – with Marbled Whites, Spanish Gatekeepers, Clouded Yellows and Great-banded Graylings especially numerous – together with a frantic band of pollinators working the Scabious, Knapweed and Chicory from dawn ’til dusk.

[click any image to enlarge to full size]

By night as well: five nights’ trapping, when weather conditions permitted, produced a very respectable list, with some stand-out highlight moths and other denizens of the night. And for the first time in four years we were not ‘plagued’ by thousands of Pine Processionaries. Either we missed the peak emergence, or local control schemes are having an effect.

It would almost have been possible to fill the week effectively without leaving Berdún. But as daytime temperatures peaked at 37°C, the prospect of ten degrees or more cooler at higher altitudes was a good enough reason in itself to chase up the higher mountain specialities.

Not just butterflies, but also those ultra-charismatic day-flying moths, such as burnets, foresters and clearwings…

…and a vast range of other exciting and entrancing invertebrates…

…with a wonderful floral supporting cast.

I could go on. Birds and other vertebrates. The food and wine. The views, weather and good company. All will feature in the comprehensive report to come. So I shall close with tales of serendipity, when the holiday was drawing to a close and circumstances conspired to give us three of the most hoped-for but unexpected and unplannable times of the tour.

On the penultimate full day, the weather was breaking down. Torrential rain was forecast, so we remained close to home, in a meadow at the top of Biniés Gorge, just 5km away. In drenching humidity, the Brambles, Dwarf Elder, Scabious and Knapweed were almost literally dripping with butterflies, burnets, beetles, bugs and flies of every description, such biodiversity and bioabundance it gives hope for the planet once the malign curses of pollution and pesticide drenching are consigned to history.  A cornucopia at every turn, everything seemingly feeding voraciously in advance of the coming deluge. And what a deluge that evening, 70mm or more of rain, so intense it caused a major cliff fall, blocking the road to our Garden of Eden …

The following day, after the storm, the air was fresher and fewer insects ventured out. We ended the final full day at Berdún Marsh, where our last gasp reward, as the butterflies tentatively came back to life, was our one and only, much hoped-for, but never expected Algarve Burnet, almost completing the set of possible Zygaenas.

And then on the way back to the airport, lunch at Agüero, among the Strawberry-trees. For a purpose, as I ruefully explained after lunch, given that the object of our desires had not appeared. But no sooner had I said ‘Two-tai….’ than Peter shouted ‘Two-tailed Pasha’ as one sailed around us, up into the treetops and away. No chance of photos, but our passion for pashas somewhat sated, we headed home blessed by happenstance that no amount of planning could have ensured.