Lepidoptera – Page 24 – David Bradley Science Writer

Moths, dull, grey, night-flying insects?

Ask anyone who isn’t a moth-er to describe a moth and usually terms such as dull, grey, brown, night-flying, drab, dingy, useless are the ones that arise. Someone might go so far as to describe them as the boring relatives of butterflies. Well semantics aside, butterflies are just a sub-group of the moths, they’re all Lepidoptera, but they’re anything but useless and many of them fly during the day and are incredibly vivid and bright.

Perhaps the most vivid and bright of the British species is a moth I’d not seen until today, only in books. It is the Emperor Moth, Saturnia pavonia, the only member of the Saturniidae, the silk moths, found in the British Isles.

The males are very brightly coloured, the females a version where the colours look as if they have been desaturated. The male flies during the day, the female at night. Both male and female have a vivid spot on each fore- and hind-wing that give them the appearance of having two pairs of eyes looking back at a predator. The species is actually fairly common across the British Isles although it favours heathery heathland and open country, but that does include Fenland, of which we have plenty hereabouts.

Female Emperors [should that be Empress moths? Ed.*] exude a pheromone to alert the day-flying males to their presence and their urge to mate. The males can detect picograms of sex pheromone on the wing with their feathery antennae. Purportedly, they can sniff out a female from up to ten miles.

Other Saturniidae moths in Japan and the Americas seem to use hexadecadienals and esters of those compounds as their sex pheromones. I’m yet to find a paper that isolated and characterised the sex pheromone of S pavonia. Nevertheless, you can buy a little lure impregnated with the sex pheromone. A moth-er might hang such a lure in the garden on a sunny and breezy day in the hope of attracting an Emperor, which is what I did.

First sighting was today. He wouldn’t settleÂ and I couldn’t safely net him, so I snapped away 100+ shots and maybe got 4 where the moth is in focus and in the frame.

*There is no “Ed.” it’s just me.

Luring in the Emperor

I ordered a pheromone lure for the Emperor Moth from ALS today. It’s just arrived and now it’s hanging in one of those little laundry tab string bags, out in the garden, blowing in the breeze purportedly drawing in the male Saturnia pavonia…but nothing yet. It’s getting late in the day for this day-flying moth, so I might pack the lure away in a freezer bag in the freezer and try again tomorrow. Intriguingly, the female which looks like a greyed out version of the male is a night-flyer.

Meanwhile, I cannot find the chemical identity of the female sex pheromone for this species. I can’t seem to find a reference in my usual journal searching, although three US Saturnia species apparently use a long-chain aldehyde, (E4, Z9)-tetradecadienal. I will keep searching. This is where my passion for biology and chemistry overlap, you might say.

UPDATE: I discovered that S pavonia had two older names, not just Pavonia pavonia, but Eudia pavonia. As soon as I learned the latter, it was easy to find a research paper discussing the pheromone – (Z)-6,(Z)-11-hexadecadien-1-yl acetate, which is a close relative of another sex attractant pheromone, gossyplure, which is used in commercial breeding control of pest moths. Read more about it here.

This species is the only member of the Saturniidae that lives in the British Isles, it is found almost everywhere here from heathland to fenland, so there is a chance of at least one turning up. It is the poster-boy of the moth world. You can go away and look it up if you like, but I’ll only post a photo when I’ve snapped one of my own.

Nut-tree Tussock (Colocasia coryli)

Pleased to see something more colourful and patterned than the Common Quakers in the actinic moth trap last night. A quick lookup in the book confirmed it as Nut-tree Tussock (Colocasia coryli). Very distinctive, but fairly common in Southern England.

The species likes Birch, Hawthorn, and Hornbeam, none of which are present in our garden, although there are birches fairly nearby. This specimen is a female? How do I know? 47 eggs laid in the pot by morning. I will leave them to hatch and release them on to a suitable deciduous tree once they do.

According to UKMoths, the species flies April to June and July to September in the south (double brooded); May to June in the north.

Later early moths

Update: Adding at least one new-for-me species every couple of days now to my mothematics gallery.Â Most interesting and fascinating were the March Moth, the Twenty-plume, and the Nut-tree Tussock (which laid 47 eggs and I am going to attempt to get them to hatch).

Female Nut-tree Tussock (*Colocasia coryli*)

Previously, I posted about some of the early moths (early in the year, that is, as opposed to Early Moths, a species of that name) that have been attracted to the actinic light of the trap.

On the evening of the 14th March 2019, it was relatively uncold, cloudy and pretty much windless.

There was a definite upturn in numbers and diversity to the trap: 4x Small Quaker, 10x Common Quaker, 3x Clouded Drab, 1xEarly Grey, and Double-striped Pug. That was the first Pug of the year, saw lots of that species and its relatives during the summer of 2018. Diurnea fagella was hanging on the LED fairylights on a cultivated honeysuckle in our garden).

By morning, the Pug had gone but a Hebrew Character and a Twin-spotted Quaker were in residence in the trap (all ethically released after logging and photographing, of course.

Early moths

I started “lighting up” again for the 2019 season a couple of weeks ago. I don’t mean I’ve taken to smoking, I’m referring to moth-ing. I’m still using the borrowed and now bought homemade scientific moth trap. It is a 40-Watt actinic light Robinson style trap and was built by my cabinetmaker and amateur luthier friend Rob, whom I’ve mentioned previously (see Mothley Crew).

Anyway, despite frosts, wind, and rain there have been a few early moths turning up in the trap over the last fortnight or so. I should note the 12-year old UV-A bulb was looking worn when illuminated so I have replaced it and am hoping for great things over the coming weeks and months.

First to appear were the Common Quakers (Orthosia cerasi) of which there have been several over the weeks. I should point out that the first moth I saw this year was 15th February in the front garden and was what made me think it might be worth lighting up again, Common Plume (Emmelina monodactyla). After the CQs, there was the relatively rare Acleris cristana on the trap, but not in it, Pale Brindled Beauty (Phigalia pilosaria), again on the trap in the evening and then in it by morning light. Hebrew Character (Orthosia gothica) moths started to show up by 23rd February and I’ve seen several not to be confused with their bristly relatives, which come later, Setaceous Hebrew Character (Xestia c-nigrum).

Then, I had Oak Beauty (Biston strataria), which lives up to its name and gives me some hope that I might get other oak-loving species much later in the year, such as the elusive Mervs and Decembers. Next was Dotted Border (Agriopis marginaria) (also saw several of this species in the gents at NT Dunwich Heath), bizarrely, but perhaps not unsurprisingly.

Then Clouded Drab (Orthosia incerta), Small Quaker (Orthosia cruda), Twin-spotted Quaker (Anorthoa munda), and Early Grey (Xylocampa areola) on 8th March. Meanwhile, there was a Yellow Horned (Achlya flavicornis) at Dunwich, which I mentioned in my Dartford Warbler blog post about the site.

As new moths appear in the trap each evening, I’ll add them to my Mothematics gallery. I usually also post to the Facebook group UK Moths Flying Tonight.

Oak Beauty (Biston strataria)

I missed out on the Merveille du Jour moths late last year, had a few November moths, and a Winter moth, but no December moths. I was beginning to think that our garden environment was too far away from oak trees for some of the species that are attracted to oaks.

But, then having started “lighting up” again a few days ago been graced with the presence of numerous Common Quaker the larvae (caterpillars) of which prefer deciduous trees, including oak and willows. Then I had a couple of Pale Brindled Beauty (Phigalia pilosaria), which also favour oak. And, best of the bunch in terms of patterning and antennae, an Oak Beauty (Biston strataria). The Dotted Border is also a fan of a range of deciduous trees.

Sex antenna

TL:DR – The males of many species of moth have feathery antennae to detect the sex attractant pheromones released by the females to allow the males to locate a potential mate, often from several miles away.

That feathery protuberance on this moth (Pale Brindled Beauty, Phigalia pilosaria) is one of a pair of antennae. What you cannot see clearly in my photo is that it’s fractal with each tiny hair on the main stem having its own array of tiny hairs and so on down to the molecular level.

Feathery antennae like this are found only on male moths and are basically its sex radar. They can catch a few molecules of female moth sex attractant pheromone on the breeze sometimes coming from miles away and guiding the male to where the female might be found. The female of this particular species has no wings and so the male must go to her to mate.

What use are moths?

Steve on one of the mothing Facebook groups told us he gave a talk about moths and was asked if we had any use for them. Other than making silk from silk worms (the larvae, or caterpillars, of the domestic silkmoth, Bombyx morihe) was at a loss to suggest any purpose to moths other than their role in the wider concept of life on earth and diversity and all that. He posed the question on the group and was offered quite a few reasons to be cheerful when it comes to moths.

Hebrew Character moth

Shaun suggested that people have an odd relationship with moths as they are used as symbols and in myths in a variety of cultures, as food – some people eat the larvae and they’re an important protein source packed with essential minerals, they can be used as invasive plant controls and for the study of genetics etc. As decoration in jewellery, clothing, tattooing etc. Paul pointed out the traditional food of Aboriginal Australia, the witchetty grub, which is the larva of several moths, most notably the Cossid Moth Endoxyla leucomochla. There are a food source in Europe too and a form of tea that is brewed with moth and other insect faeces in China.

Martin’s take was that we make use of moths for interest, study, research, and in hobbies. They “brighten our lives,” he says. They also act as a gateway into other activities and interests, such as flowers, trees, walking, travel, and friendship.

Common Quaker moth

Antony pointed out that pollination is probably the main use.

Matthew, somewhat tongue-in-cheek asked what do we use blue tits for? Or shrews? It’s not all about utility!

Roly asserted that moths have an important position in nature’s foodchain. Many birds wouldn’t exist without caterpillars for their chicks. He also added ever so slightly flippantly, I think, that his wife reckons she finds moths very handy for making her clothes look moth-eaten, proof that she needs continually to shop, though I’ve never seen a clothes moth in our closets, Roly emphasises.

Pale Brindled Beauty moth

Stewart had a research example of moth usage: Spodoptera frugiperda and Trichoplusia ni cell lines are used in the recombinant baculovirus expression system to produce proteins. The baculovirus most studied for this is Autographa californica multicapsid nucleopolyhedrovirus.

Welcome to the first moths of the year

Okay…first moth I’ve seen this year was a Common Plume (Emmelina monodactyla), which I think may well have been hibernating in our car and flew out when we arrived home on 15th February landing on a Ribes bush to be phone-photographed seconds later.

Common Plume moth

Second moth was in the trap (accidentally, as the timer had lit it up briefly evening of 19th). This moth, a Common Quaker (Orthosia cerasi), usually flies from March onwards. First time I’ve seen one. Added to the lepidoptera list and gallery.

Common Quaker moth

Apparently, to some moth-ers the arrival of brown moths, such as the Common Quaker, are an indicator of Spring being on its way.

Other moth species on the wing in February March that might turn up if you’re trapping over the next few days: Pale Brindled Beauty, Early Moth, March Moth, Dotted Border, The Chestnut, Hebrew Character, Spring Usher, The Satellite, Dark Chestnut, Early Grey, Clouded Drab, The Herald, Oak Beauty, Winter Moth (which I spotted twice in December 2018 outside the trap), Red Chestnut, Angle Shades (which appeared regularly from when I started in July 2018), Small Quaker, Yellow Horned, The Engrailed, Silver Y (another regular visitor last year).

Meanwhile, butterflies. We saw a Small Tortoiseshell on NT Tubney/Burwell Fen 14th February and then a week later (21st Feb) a Brimstone and a Peacock at RSPB Fen Drayton.

First Peacock butterfly of 2019, RSPB Fen Drayton

Winter Moths

By Christmas Eve 2018, it will be five months since I started trapping, identifying, photographing, and releasing (unharmed) moths using an actinic light trap. At the last count, I had ticked 129 moths. As the autumn drew in and winter arrived, the number of new species plummeted although other moth-ers talked of Mervs, November moths, December moths, Winter moths, Mottled Umbers, migrants, and more.

I’d seen none of those species until a Winter Moth (Operophtera brumata) finally turned up on the vanes of the trap and was sitting there when I got back from C5 the band rehearsals last night. I got a quick record shot on my phone and then persuaded him (it’s definitely a male; the females have no wings) to sit on my trusty lichen-encrusted stick for a late-night photo shoot. The inimitable Leonard C on the Moths UK Flying Tonight Facebook group corroborated my identification.

This morning, after a restful night’s sleep, O. brumata was ready for a couple more snaps prior to release back into the wild. As the name suggests, this species flies and breeds during the winter, taking flight from late autumn and on the wing until January-February. It is a relatively common species and its larvae can sometimes be found in numbers so large that they will completely defoliate small trees and so the species is considered a pest, according to UK Moths.

You can view all of the decent shots I’ve got of Lepidoptera on my Imaging Storm website where there’s also a full listing of species common names and scientific binomials.