Category: Science

There was a ludicrously ill-informed and essentially anti-scientific letter in The Graun at the weekend. It was from someone who had obviously just learned that there are a handful of people over the country who are amateur lepidopterists and regularly “trap” moths by drawing them to an ultraviolet light at night.

The letter talks of the author’s sadness on learning about moth trapping. It goes on to say that moth trapping:

must cause terror and damage their fragile wings and bodies. Most adult moths only live for days or weeks, so trapping them overnight is akin to incarcerating a human for years. That night they might have been sipping nectar and pollinating plants or providing lunch for a bat. They might have been seeking a lover or the right plant to lay eggs on so that their offspring can eat and be safe — both are harder now that their numbers have declined and their habitats have been lost

Terror? Incarceration? Sipping nectar? Providing lunch? Seeking a lover?

Moths are insects. Yes, they are beautiful. They do not take part in those activities in such a nuanced anthropomorphic sense nor have the ability to feel the terror the authors mentions. In fact, moths are drawn to a light, as everyone knows, and most settle down in the trap unharmed to be identified, logged and released back into the wild the next day. I’ve discussed all this before. One obvious benefit to any trapped moth is that they will not be eaten that night. A single pipistrelle bat will eat 3000 insects a night on a balmy evening, a large proportion of those insects will be micro moths and caddisflies. There are still plenty to go around even if a few dozen are trapped.

Moreover, most moth-ers are very much eco-minded and plant native plants and create a habitat on their site whether garden or nature reserve that encourages all wildlife, including moths and provides the native plants for insect larvae, and draws in birds and bats. The most important aspect though is that it is usually a scientific endeavour that involves logging and reporting species so that science has a better perspective on the world of moths, and moth trap intruders. We can then know when the migrants turn up, how weather variation and climate change are affecting species over the years and feed this back into the bigger picture of changes in wildlife. Without moth traps we wouldn’t really know that the night-flyers are out there at all or whether or not their numbers are rising or falling, and the author of the letter would be totally unaware of their “beauty” nor their “mystery”.

Retired teacher and moth enthusiast Graham Stocks had this to add to the above article

Those of us above a certain age grew up with 'Nature Tables' at school and received a good grounding in our education of the natural world - something children these days seem to be lacking. As we know, there are Coleoptera Groups, Hymenoptera Groups and goodness knows how many other specialist animal and plant-watchers busily at work doing absolutely no harm at all. Quite the opposite, of course, we're all keeping a watchful eye on life around us. These facets of the natural world are effectively canaries in the mine, telling us what's happening to our natural environment - sadly, most of it not for good but ill.

There have been a couple of responses from scientists, to the original ignorant letter, that explain the rationale for ethical moth trapping and recording and reporting of data.

Moth Bird Watch 7 – The anything-but beige brigade

Ask most people to describe a moth and usually terms such as dull, grey, brown, night-flying, drab, dingy, useless, clothes eater, are the terms they will use. Some might go so far as to describe them as the boring relatives of butterflies. Well, nothing could be further from the truth the Lepidoptera (meaning scaly winged) are a vast group of insects fare more diverse than just the butterfly sub-group. Many of the 2500 recorded different species in the British Isles are anything but dull and grey, many of them fly during the day and most of them have quite exotic names.

Perhaps the most vivid and bright of the British species is the (Small) Emperor Moth. This is the only member of the Saturniidae family, the silk moths, found in the British Isles. The males are very brightly coloured. You could easily mistake him for a butterfly. The females have a similar patterning with four “eyes” one on each wing. The male flies during the day, sniffing out the sex pheromone of the female, which will be passively reclining in heath or fenland undergrowth (she only flies at night).

Another local moth that exploits pareidolia to fool predators into seeing a bigger face staring back is the aptly named Eyed Hawk-moth. With its wings folded it looks like a well-camouflaged moth that might be mistaken for a leaf among the leaf litter. Startled, however, it moves its forewings forward revealing the bright “eyes” on its hind wings.

As, we moved on to the hawk-moths, a quick shout out for this small, but perfectly formed, group of large moths. Among their number, we have the lime hawk-moth, the privet hawk-moth, and the poplar hawk-moth, the larvae (caterpillars) of which feed on those respective trees and shrubs. The adults are all quite well-patterned, but their larvae can be even more so.

Also among their number is the hummingbird hawk-moth, which we occasionally see in this country when Southerlies blow them in from warmer climes. There is also the death’s head hawk-moth, which to our eyes takes pareidolia to another level, this enormous dark moth appearing to have the blank, staring face of a skull on its back.

Then, there is the stripy olive-green and cerise elephant hawk-moth, which resembles a dangling fuchsia flower when hanging from a twig on its favoured species for laying its eggs…the fuchsia. Incidentally, its name has no relation to its large forewings looking like elephant’s ears, nor any allusion to pink elephants. The caterpillar is long, thick, wrinkled looking and grey-brown…and simply looks like an elephant’s trunk (but with a couple of pairs of eyes at one end!).

We do have an odd relationship with moths; there is lots of folklore and symbolism, especially around the likes of the death’s head hawk-moth. Some people may well have mottephobia, a fear or loathing, of moths, but, they do have their place in the natural world.

Despite their larvae often being plant pests, often the nectar-loving adults are important pollinators on a par with bees and flies. The aforementioned larvae are a great source of protein for a wide variety of birds, such as our garden favourite, the robin, as well as a lot of carnivorous mammals. The flying adults represent the staple diet of bats. A single pipistrelle bat might use its sonar to hunt and eat several hundred moths every night. Of course, people eat moths and their larvae too. The famous Witchetty grub will be familiar to anyone who has visited Australia or watched “that” challenging reality TV show with the so-called celebrities.

Admittedly, there are many, many species that are variations on the theme of basically beige, but with different patterns of speckle. However, there are so many more that are far more fascinating with their hearts and darts, their chocolate tips, their Silver Y and Satellites, their punctuation marks and Hebrew writing, their resemblance to twigs, their disguise as a bee or a wasp, and yes in the case of the Lime-speck Pug and the Chinese Character their resemblance to a bird dropping.

Incidentally, of all the 2500 or so species of moth we find in the British Isles, the larvae of just one a few eat natural fibres such as wool and cotton. So, feel free to dangle some stinky mothballs in your wardrobe to protect your D&G and your Calvin Kleins, but don’t attempt to swat that big “logger” flying around your bedroom light, it could well be as beautiful as a butterfly and it might give you a start if it stares back at you when it flies off.

Spottin’em in Cottenham: Recent sightings, of moths

In a departure from our normal programming, here is a short list of some of the moth species seen in Cottenham at the time of writing: Willow Beauty, Small Magpie, Mottled Rustic, Common Pug, Garden Carpet Heart & Dart, Heart and Club, Treble Lines, White Point, Dark Arches, Shuttle-shaped Dart, White Ermine, Angle Shades, Vine’s Rustic, Rustic Shoulder Knot, Large Nutmeg, Peppered Moth, Lime Hawk-moth, Eyed Hawk-moth, Privet Hawk-moth, Elephant Hawk-moth, Poplar Hawk-moth, Common Swift, Common Wainscot, Gold Triangle, Burnished Brass, Large Yellow Underwing, Bright-line Brown Eye, Flame Shoulder, Light Brocade, Light Emerald, Treble Brown Spot, Small Seraphim, Oak Hook-tip, Chocolate Tip, Buff Ermine…the list goes on. Indeed, you can see my 2019 species records and counts here.

Among the dozens and dozens of Yellow Underwings of various kinds, the milieu of Rustics, the Rose-flounced Tabbies, the Mouse Moth, the Least Carpets, a solitary Elephant Hawk-moth, and several tens of other species, there was a crispy-looking golden wonder that came to the actinic light trap in the night yesterday.

A female Oak Eggar, Lasiocampa quercus.

The species is sexually dimorphic, so it was obvious this was a female even before she laid a dozen eggs in the specimen pot.

Incidentally, the species is called Eggar because the silky cocoons the larvae make are quite large and obviously ovoid (as Peter Marren explains in his book, reviewed here earlier this year), although the pupa of this species also looks like an acorn, hence the “Oak” in the name, the larvae don’t feed on Quercus tree species, they prefer heather, bilberry, bramble, sallow, broom, blackthorn, hawthorn, hazel, and sea-buckthorn, according to UKMoths. The red-brown males are day-flyers, the females nocturnal.

It’s a year to the day since I first got bitten by the mothing bug, as it were. Initially, it was all about seeing what turned up at the scientific trap and trying to get a photo or two of anything interesting. I did keep a record of new species and I think had logged and photographed approximately 130 of the 2600 or so species we see in the British Isles by the end of the long, hot summer of 2018 and into the winter.

I kept on lighting up until well into December in the vain hope of spotting some of the late autumn and early winter moths with marvellous names such as Merveille du Jour and the more obviously named November and December Moths. It wasn’t to be, but a few others did turn up late in the season, no Mervs, but a November or two.

I started occasionally lighting up again in February 2019 and then more seriously into the spring as the Quakers and Muslins began to turn up. As of my first year anniversary, I have logged and photographed 270 moth species. So a little more than 10% of those we might see across the country.

Weirdly, the temperature yesterday and today are the same as they were this time last year and I had high hopes for some of the summer highlights, the less common Pine and Convolvulus Hawk-moths, some Garden Tigers and the like too (they’re spotty and used to be called Leopards). None of those last night, but I did have my first Canary-shouldered Thorn of the year (it was very worn) and a motley crew of Mottled Rustic and the usual greys and browns, and small flat moths that look like bird much, such as the Lime-speck Pug, and the black and white Carpets, Least and Garden. Also new to me was the Least Yellow Underwing, pictured above.

You can see my moth-trapping logs here. And, just so you know, all moths are released unharmed at dusk away from the trapping site. I’m still holding out for some more NFM species this week as the heatwave persists. Meanwhile, I asked the good people of the Moths UK Flying Tonight Facebook group what they were hoping to see.

Claire W got 2 Ruby Tigers “which was lovely” and said she too would love a Pine Hawk!

Mandy H is hoping for “Small and select.”

Dave M had a small trap out in woodland last night, and got a Pine Hawk! Also got a Gypsy and Oncocera semirubella, not normally found in such habitat! I have another trap out at my place of work for tonight. Either I’ll get something amazing or be knee-deep in LBJ’s.

Jo W lit up last night and got her first Green Silver Lines and Least Carpet. I always find it amazing how something is common for one area yet rare in another!

Rory M asked how we all find these moths and was advised by Sue T that it’s usually a trap

Andrew D had a jersey tiger last night

Stephen T said any Hawk would be good.

Bill M (the VC29 County Recorder) suggested Crimson Underwing, Clifden Nonpareil, Scarce Bordered Straw, White-spotted Pinion, True Lovers Knot, The Latin, Spoladea recurvalis all in his dreams. Although he reckoned two of those are possibilities and that a Jersey tiger would be nice also.

Leonard C was not too worried about what turns up but an Orache would be nice.

Dennis C said an Old Lady (any old lady!) would make my night … I disturbed one behind the garage once soon after we moved in, but I’ve never seen one to photograph. He did have three Jersey Tigers, which are on several people’s wishlists.

Wayne C is after Buff Arches and Bagworm Moth.

Alan S told us he is lighting up. Had a big haul in the field last night including Leopard, Pine Hawks, Small “Ellie” Hawk. Feels like another good one tonight.

Elarna R said a Jersey Tiger flitted past in the garden a little while ago (SE London) she was worried she wouldn’t see any this year, he’s a bit late! [This species was one of the first I saw on my first night trapping at home, dB/]

Paul H revealed he’s not fussy about what turns up “just as long as there’s something new to science in tonight’s catch.”

Su R told us her dream is an Alchemist! and Allan R is after a Sycamore

As regular readers will know, I borrowed a scientific (albeit home-made) moth trap from my good friend Rob, here in Cottenham on the edge of the Cambridgeshire Fens. He had been telling me about mothing for a while and how he and his kids had been keen back in the day. The trap was lying dormant in his garden workshop.

I had occasionally snapped the odd large moth, a Hummingbird Hawk-moth in France a Pale Tussock in our conservatory, some Cinnabar moths and Six-spot Burnets along footpaths of Aldeburgh and other places. The inspiration came to borrow the trap and have a go at mothing properly on the 23rd July 2018. Mrs Sciencebase spotted a rather large and patterned moth on the warm, west-facing outside wall of the conservatory. It turned out to be a Copper Underwing (Amphipyra pyramidea, Linnaeus, 1758).

I photographed this specimen and then contacted my friend Rob to ask if I could borrow the trap. He set it up for that night and I paid a visit the next morning to see what had come to the actinic ultraviolet light (lots of species!). After we photographed and released those back into the wild, I left with the trap and got ready to set it up in our back garden with its attendant egg trays (they act as nice resting places for the moths that enter the trap where they can roost overnight). Next morning, I had a good haul of Lepidoptera, Ruby Tiger, Burnished Brass, Large Yellow Underwings, and so many more. It got me hooked, although I wasn’t recording the specimens properly at that time. That came early in 2019, with the installation of a new UV bulb and the emergence of the spring moths.

 

I have been keeping quite fastidious records since and confirming new species of which I couldn’t be sure of an identification via the Flying Tonight UK Moths Facebook Group, the @MothIDUK Twitter (aka Sean Foote), as well as the UK Moths website, and my Collins Complete Guide to British Butterflies and Moths (Sterry, Cleeve, and Read, 2016).

Anyway, night of 17th July 2019 it was balmy and dry. Post-pub, took a look outside to see what kind of activity there might be around the moth trap. Plenty! Including, you guessed it, a Copper Underwing. He brings me full circle with the mothing. Of course, this just represents a punctuation mark, a comma if you will (that’s a butterfly, Polygonia c-album), and I will carry on logging old and new species. Indeed, the final haul on the morning of 18th July 2019 was more than 180 moths of 50+ species. Most of those I have seen several times before.

There were four Elephant Hawk-moth, a Pebble Hook-tip, Brimstone, endless Least Carpet and Garden Carpet, lots of Rose-flounced Tabby, various Yellow Underwings, Bird-cherry Ermine, Thistle Ermine, Buff Ermine, a good crop of Dark Arches, and more. You can see the complete list in that record sheet I mentioned above.

By the, way the labial palps field note for Copper Underwing vs. Svensson’s has been shown to be unreliable, definitive marker is a pale, central patch on the underside of the hindwings of the former as seen above.

Rehearsing with C5 the Band last night for forthcoming gigs. Got back to catch a glimpse of the partial lunar eclipse, a quick hello to the family, and then out to the UV scientific moth trap on a balmy, partially cloudy night to see what was around.

There were lots of moths, beetles, caddisflies, lacewings, and more. By morning counted more than 200 specimens of moth of more than 44 species. It had been a dry, much warmer night, still with a minimum of 13 Celsius though. Numbers and diversity were much improved on previous nights. Two new for me macro species: Dusky Sallow and Small Emerald.

There were two lovely Yellow Shells (just one pictured), and a Thistle Ermine.

There were a couple of Agapeta hamana (one richly coloured (pictured), the other much paler), Smoky Wainscot, and Bulrush Wainscot, new for me), and Codling moth, with a bronze ring.

Least Carpet and Chrysoteuchia culmella were joint first on numbers at about 25 each, there were also four Privet Hawk-moths, but no other HMs. I think I saw a couple of Canary-shouldered Thorns on plants in the garden before bed, but didn’t get a positive ID. Maybe later in the week.

Several of the species new to me that I’ve blogged about here and added to my Lepidoptera gallery were identified or confirmed with the assistance of @MothIDUK and members of the Moths UK Flying Tonight Facebook group. Any labelled incorrectly, that will be entirely my fault, please let me know if you spot any ID errors on any species on the blog or in the galleries over on Imaging Storm, thanks.

The Box-tree Moth (Cydalima perspectalis, Walker, 1859) is an invasive species that has reached the British Isles. It originated in Asia and its larvae feed on, as the name would suggest, various species of Buxus, box tree (known as boxwood in the US). It turned up in my scientific trap night of 11th July 2019. I almost missed logging it as it flew up to a window as I was opening the trap. I’ve sent a record to the Cambridgeshire County Record.*

It’s a pretty pearlescent moth and was first seen in Europe in 2006, in Germany, specifically. It is most likely to have hitched a ride on imported Boxus plants as eggs or larvae. It was first recorded in the British Isles in Kent in 2007, spread to Surrey, into London and the home counties and beyond. It is not known which counties it is now resident in, but there have been sighting, often to moth traps, across most of Southern England and further North. It has been recorded in Fife in Scotland. Spotted in Toronto, Canada in 2019.

The larvae will devour Buxus leaves and so disfigure ornamental and topiaried Buxus. Of course, it is the importing of particular species of these plants that has allowed this moth to spread, reinforcing the mantra that planting native species should be the ethical horticulturalists way forward.

* Bill Mansfield the County Moth Recorder got back to me this morning with a response to the Box-tree Moth sighting:

Box tree is pretty well established in Cambridge city from Trumpington to North Cambs so no surprise you've got it too. I dread it arriving in Ely, if it's not already here. I've 20-metre of box hedge I've nurtured for eight years against everyone's best advice...

Amateur Lepidoptera expert friend Leonard has not “ticked” one of the species that were new to me in last night’s scientific trap experiment. The species in question looks quite remarkable: Marbled Clover, Marbled Clover (Heliothis viriplaca). So, that’s bonus points to me today, surely?

In fact, a day later, it seems that quite a few of the experienced moth-ers on the Facebook group there have not seen this species. It usually inhabits The Brecks, but there is evidence that there are migrants. We’re not that far from The Brecks here, but this could well be a traveller that just turned up almost randomly here.

Overall the haul for the night of 10th July 2019 and into the morning was more than 210 specimens of more than 56 moth species. There was a lot also among the folds of the white sheet I have hanging by the trap.

It would be interesting to know whether the sheet really makes a difference, as there are several species that don’t seem to enter the trap often that I have seen in the dark close to the trap (the large, lemon sherbert coloured Swallow-tailed moth, for instance), but are attracted by the ultraviolet let, and simply hang around the folds of the sheet. But they might just as easily roost on the brickwork and glass of the conservatory, in fact some do. Old Lady has appeared in the trap twice now (different specimens) and they’re not really even meant to be attracted to light.

I also wonder if all my wildflower planting and cultivating night-scented plants (Nicotiana, Stock) in the garden is making a difference, attracting moths by scent that are then drawn to the UV. I only started this experiment at the end of July 2018, so it is impossible to know, and the weather was very different in the summer of 2018, so there’d be no comparison even if I had started earlier and kept detailed records then.

Either way, I’ve just passed 250 species identified and photographed. This, I’d say is the half-way mark, given that two other moth-ers in the village here are both at the 500 mark after several years of scientific trapping.

If you want to follow the detailed logging of the experiment, my spreadsheet is available here.

All of the photos on this blog post are of species new to me on the day or writing. 11th July 2019.