Lepidoptera – Page 7 – David Bradley

The Moth Trap: How I came to see the lepidopteral light and how you can too

TL:DR – How to fall in love with moths and mothing.

Regular Sciencebase readers will know only too well that back in July 2018 I got hooked on moths. An enthusiastic friend lent me a moth trap he had built himself for his children many years ago. The trap is basically a wooden box with a plastic funnel and an ultraviolet light supported by stiff plastic vanes).

The UV light attracts the night-flying creatures, some of them bump into the vanes, drop into the funnel and then find a cozy corner in one of the empty egg cartons put inside the box before “lighting up”. The amateur, or indeed professional, lepidopterist examines the catch at dawn, recording species and species number and later releasing the moths off-site back into undergrowth or bushes.

It’s fascinating and fun and at the time of writing almost five years since I first “lit up”, I have seen, photographed, and logged well over 450 different species of moth in my Cambridgeshire garden. The variety and diversity of shape, size, colouration, and patterning is incredible. I must admit that I had always been a little irrationally wary of moths despite the fact that they are completely harmless. After all, unlike many other types of insect, they don’t bite and they don’t sting.

It was a test run with my moth-trap maker friend, Rob, who had stopped trapping moth and turned his hand to making guitars, that got me hooked. He lit up one July evening and invited me to the grand opening the next morning. There must have been 100 or more moths in the trap, a few that were simply dull and grey or brown, but among them some huge hawk-moths, some shiny green moths, orange ones, red ones, patterned ones, ones with daggers and arches, all kinds.

Having got a little up close and personal with the Poplar Hawk-moth in Rob’s trap, allowing it to perch on my hand while I took a close look, this single dose of informal aversion therapy, seemed to cure my mild phobia about moths, my mottephobia. I had previously photographed one or two moths that turned up in the house, but essentially I made 180-degree about turn from aversion to addiction. I borrowed Rob’s trap from him permanently as summer turned to autumn, and paid him an honorarium for the privilege.

I have trapped regularly in all that time since. I’ve also acquired various other UV sources including a LepiLED. The low-wattage LepiLED runs off a USB battery pack and is entirely portable, so I have taken it on a few excursions with an adapted, portable Heath trap I bought off another ex-mothing friend. My pots for managing the morning moths came from yet another ex-mother friend!

I have also bought pheromone lures to attract various species, including Emperor and some of the clearwing moths. I have planted wildflowers and various scented flowers in the garden to attract species like Hummingbird Hawk-moth and Convolvulus Hawk-moth. A recent addition to my mothing measures was to buy a bottle of amyl acetate (used in aromatherapy apparently despite it being toxic). It has a strong fruity smell and is entirely harmless to moths but attracts various species.

Is it a kind of madness, this mothematical obsession? Maybe. Am I happy to be part of #TeamMoth and to regularly declare that #MothsMatter? Too right! I have written about the ethics and importance of moth-trapping as a citizen science effort and I have also written about why moths really do matter. Would I recommend it as a hobby or citizen science project? By my scaly wings, I would, of course!

A moth called a Clouded Yellow butterfly — A moth known as a Clouded Yellow butterfly

Incidentally, butterflies are just one grouping within the Lepidoptera, just like the less publicly familiar groupings, the noctuids, hawk-moths, erebids and others. Indeed, butterflies are grouping within the broader clade we know as the micro moths (an unfortunate term that doesn’t always reflect their size but is rather connected to their evolutionary ancestry). The other major clade is the macro moths, but there are some micros that are bigger than even the biggest macros.

The tragedy is that their numbers and diversity have declined considerably since my childhood in the 1960s and 70s. Perhaps even in the last five years since I started mothing. First full year, I would see a couple of hundred moths of 70 or so species, but in the last couple of years those numbers have been much lower even on peak summer nights.

What’s in a name when it comes to moths?

TL:DR – It was learning some of the common names for the macro moths that helped piqued my interest in being an amateur lepidopterist and citizen science moth-er.

There are around 1800 moth species seen in the UK. A large proportion of these are the so-called micro moths (which isn’t about size, but rather their position in evolutionary history) and they are usually referred to by their scientific name rather than a common name although some do have colloquial names too. But, almost all of the macro moths have an intriguing common name. Here are some of my favourites

The Clifden Nonpareil (Catocala fraxini) – This large moth is known for its striking appearance, with its black and white wings and a powder blue band across its hindwings. Its name, “Nonpareil,” means “unrivaled” in French and the Clifden, is the archaic spelling of Cliveden, as in Cliveden House the site where it was recorded scientifically in the early days of formal entomology.

The Buff-tip (Phalera bucephala) – At rest, this moth look like a piece of broken silver birch twig. The Buff-tip of its common name refers to the colour of the ends of its forewings.

The Merveille du Jour (Griposia aprilina) – This moth’s name comes from French, meaning marvel of the day. It’s a stunning green moth with intricate black patterning on its wings, it blends in well with lichen-covered surfaces.

The Coxcomb Prominent (Ptilodon capucina) – When at rest this otherwise brown and relatively innocuous moth has a profile shape resembling the a cockerel’s comb. The colouration and shape make it otherwise resemble a curling autumnal leaf.

The Herald (Scoliopteryx libatrix) – This moth is known for its stately orange orange wings, when at rest it looks like a shield or perhaps the penant that might hang from a horn player’s instrument at a ceremony.

The Old Lady (Mormo maura) – The Old Lady is named for its resemblance to black or dark-brown silk commonly worn during mourning by widows of the late 18th Century when the species was named. It is sometimes known as the Black Underwing or the Grave Brocade, although both those archaic names are frowned upon.

The Vapourer (Orgyia antiqua) – This moth, occasionally known as the Rusty Tussock, is as that latter name would suggest largely brown, although the males have a white spot on each forewing which gives something of the appearance of eyes staring back at wouldbe predators. It is known as The Vapourer because the wingless and so flightless females exude pheromones, producing a vapour trail to attract the day-flying males.

The Shark (Cucullia umbratica) – This fairly large moth gets its common name from its grey and sleek appearance when at rest and its thoracic crest adds to the allusion of a shark-like shape.

The Ruby Tiger (Phragmatobia fuliginosa) – This moth is known for its striking appearance, with its bright red colour and furry body. It bears little resemblance to the other “tiger” moths, which have a more butterfly-like appearance, although only the Jersey Tiger as stripes, the others are spotty.

The Nutmeg (Anarta trifolii) – This moth is named after its speckly grey appearance, which must have reminded the early entomologists of the spice, perhaps the face of a piece of nutmeg after grating.

I reviewed Peter Marren’s excellent book about the names of the Lepidoptera, Emperors, Admirals, and Chimney Sweepers, on Sciencebase some time ago. I still refer to it on an almost daily basis during the peak mothing season.

A smelly boost for your mothing life

TL:DR – Recent research has demonstrated that adding the volatile organic compound amyl acetate to a scientific moth-trap can boost the number of moths attracted to the UV light by almost a third.

A social media discussion about UV light sources for scientific moth-trapping, the type of vanes on the trap, and the environment in which one traps brought up some interesting thoughts. Several moth-ers use double sources to give them a better chance of enticing numbers and diversity to their traps. Although moths have been shown almost always to simply opt for the most energetic (higher frequency, shorter wavelength) when given a choice. There is evidence that black lights (UV bulbs painted black) are not so effective for attracting those species that are drawn more to visible light.

Also, it seems that white plastic vanes seem to work better than other types of vane and certainly better than rain-shield supporting rods on the commonly used Robinson and Heath moth traps. It also seems that the specific terrain and vegetation can affect numbers and diversity in some ways more than light source or other factors. There was also some recent work on how low-wattage UV light sources have a very limited range of attraction, but also the range varies among macro moth families, some attracted from 30 metres others from just 10 metres.

Anyway, in the discussion, fellow moth-er Stephen Roughley mentioned a paper by Chris Tyler-Smith and Yali Xue in the journal Ent Rec, “Amyl acetate increases macromoth catches in light traps” 2021, 134(6), 315-321, that looked at how lepidopterists might boost their haul for scientific and citizen scientific purposes. They suggest the use of a simple organic molecule that smells of fruit, called amyl acetate, amyl is an alternative name for the five-carbon alkyl chemical group pentyl, to augment one’s trapping. They demonstrated that amyl acetate boosted the number of macro moths drawn to the UV trap by up to about a third. Strictly speaking, the product contains 3-methylbutyl acetate, so five-carbon group but not in a straight chain.

Chemical structure of the ester amyl acetate — The ester amyl acetate smells fruity

The molecule, sometimes known as pear oil, is used as a flavouring agent, as a paint solvent, and in the preparation of penicillin. It is also the fuel for Hefner lamps. But, it is also found naturally in the volatile organic compounds exuded by ripe pears and presumably other fruit and fermenting or decaying vegetable matter.

I asked author Xue about the work. “We only tried amyl acetate from Etsy, but suspect that moths would not care about the grade, and any that smells like pear drops to a human would be fine, they told me. “We used enough to moisten a cotton wool pad and placed this beside the trap in a metal bowl as the solvent dissolves plastics.”

Many species of moths are known to be attracted to the odours given off by ripe fruits and flowers. There is a suggestion that some female moths may well be particularly attracted to such odours, including amyl acetate, as they seek out ripe fruit in which to lay their eggs. Indeed, it’s worth noting that a lot of moths that are not necessarily interested in light can be drawn to a strong-smelling sugary solution made from molasses boiled with beer or wine and various other concoctions. Most moths use their olfactory senses to locate food, mates, and suitable habitats, so this is perhaps not surprising. It was the technique of sugaring to attract moths that inspired the team. (See also wine roping). Amyl acetate mimics fruit odours and so should attract moths. Indeed it has been used in the past as a sugaring ingredient.

The team suggest, however, that the chemical simply applied could substitute for sugaring concoctions and might boost moth trapping where scented flowers are not present at a site. It all adds to the useful data that might be gathered to feed back to moth recorders for scientific purposes and to show where and when various species appear around the country. I have previously discussed the pros and cons of moth-trapping on Sciencebase.

Why do some moths have eyes on their wings?

TL:DR – A few examples of plants and animals that use disguises.

Lots of animals and even plants have evolved to have a visual resemblance to other organisms. The flowers of the Bee Orchid as the name would suggest look like female bees and as such attract roving male bees who alight on the “female” hoping that they’ve found a mate. In so doing, they inadvertently pick up pollen from the male part of the flower and this is transferred to female parts of the next “mate”, thus pollinating the plants.

Bee Orchid closeup — Bee Orchid complete with fur and pollen sacks

There is a bird that has evolved to look like a snake and so ward off predators. Indeed, not only does it look like a snake when it postures defensively, but it writhes around so that its head really does look like a snake about to pounce.

Among the lepidoptera, the moths and butterflies, there are so many disguises it is hard to know where to start. The Bufftip moth resembles a piece of snapped of birch twig while the unrelated Buff Arches resembles a piece of flint on a stony woodland floor.

Buff Arches moth resembles a chunk of flint

There are so many examples of this faking it camouflage among the Lepidoptera. Perhaps the most obvious examples of this pareidolia are among the species that have “eyes” (ocelli, singular ocellus) on their wings. The European Peacock, for example, roosts with wings closed. The dark undersides are sufficient disguise in the dingy nook of a tree during hibernation but if disturbed it flashes its eyes, which to a bird or other predator look shockingly like a big face staring back, the face of an animal that might fight back rather than a gentle butterfly.

Dark undersides of Peacock butterfly wings

The Emperor moth also has four eyes but does not have the advantage of being able to fold its wings flat against each other. When disturbed or agitated it opens out its wings to reveal four scary eyes staring back at a predator.

The staring "face" of an Emperor moth at rest — The staring “face” of an Emperor moth at rest

However, even at rest with its forewings covering its hindwings the Emperor is always watchful. Indeed, if one imagines a predator flying into to check out tasty morsels on the heather, it will be shocked to see something resembling a predator staring back at it!

Why moth?

TL:DR – Reasons to be a citizen scientist lepidopterist.

I’ve been mothing since July 2018. By which I mean I have used a lure (an ultraviolet light source) and a trap to allow me to monitor, count, photograph, and release the moths that pass through my garden at night. It has apparently become a popular hobby, particularly among wildlife enthusiasts during the time when we were all in covid lockdown and had limited opportunity to be out and about exploring nature in situ, birdwatching, gulling, seeking out wildflowers, etc.

There is an argument that mothing might be detrimental to the already heavily threatened populations of moths, but I think the benefits in terms of scientific insight and education far outweigh the negligible impact on moth populations.

Moth trapping and recording is a valuable citizen science activity that allows non-scientists to contribute to scientific research and conservation efforts. The overall scale of scientific moth trapping on reserves and at research centres is far greater than amateur garden mothing.
Moths play important roles in ecosystems as pollinators, food sources for other animals, and indicators of environmental health and so understanding their behaviour and distribution can help in deciding on conservation initiatives.
Moths are often overlooked compared to butterflies (which are actually just a grouping within the Lepidoptera like any grouping of moths), but there are around 160,000 species of moths worldwide (2500 in the UK), making them an incredibly diverse and fascinating group of insects. The more we know about such diversity, the better.
Moths are also important bioindicators, as they can be used to monitor changes in habitat quality and climate.
Moth trapping and recording can help identify new species, expand knowledge of distribution and range, and range extension and reduction, as well as migration, and provide important data for conservation efforts.
Moths are often nocturnal and elusive, making them difficult to study through traditional observation methods. Moth trapping provides an opportunity to observe and study these insects in greater detail.
Moth trapping can also provide a unique opportunity to engage with the natural world and inspire curiosity and interest in science and conservation in young and old alike.
Moth trapping can be done in a non-invasive and ethical manner, with moths typically released unharmed after being recorded and identified.
Moth trapping can provide valuable data on population trends and species diversity, which can help inform conservation decisions and management strategies.
Moth trapping is a relatively low-cost and accessible activity that can be done by people of all ages and backgrounds in their own gardens or even from the balcony of a tower block, making it an ideal way to engage a wide range of people in science and conservation. Lots of nature reserves running mothing events open to the public

Nocturnal pollination #MothsMatter

TL:DR – Many species of moth are important nocturnal pollinators.

2018 was the year I took a serious interest in studying moths in my garden having been loaned a scientific mothtrap by a friend in the village. It was late July that year that I fell in love with the “nocturnal” Lepidoptera.

By the September, I’d recorded about 120 species of animal I’d never noticed, seen, nor observed ever before. In subsequent years I added yet more species. There are about 1600 moth species in the UK and I have ticked 464 (as of 1 April 2023). That same month there was some research demonstrating once again why moths matter and why we should not dismiss these remarkable creatures. The paper:

Construction, validation, and application of nocturnal pollen transport networks in an agro-ecosystem: a comparison using light microscopy and DNA metabarcoding

Callum J. Macgregor, James J. N. Kitson, Richard Fox, Christoph Hahn, David H. Lunt, Michael J. O. Pocock, Darren M. Evans First published: 17 September 2018 https://doi.org/10.1111/een.12674

The study compared two methods, light microscopy and DNA metabarcoding, for constructing pollen-transport networks of nocturnal moths, with a focus on their feeding mouthparts. The researchers found that DNA metabarcoding detected more pollen on individual moths and more interactions per moth species compared to microscopy.

The results also showed that the pollen-transport network metrics differed between the two methods due to their varying abilities to detect multiple pollen types per moth and to separate morphologically similar or related pollen. The team also demonstrated some unexpected moth-plant interactions using metabarcoding, revealing new insights into nocturnal pollination systems.

The authors suggest that while the two methods revealed similar yet distinct networks, the potential applications of metabarcoding for studying plant-pollinator interaction networks, especially for understudied pollinators like moths, are encouraging.

Red-green Carpet

TL:DR – It’s spring and at least one hibernating moth, the Red-green Carpet, has arrived in our garden so far this year

Lit up with my Heath trap again last night and despite the rain, but perhaps because it didn’t drop below 9 Celsius there was a small clutch of moths to ID and record this morning. Specifically, 2x Clouded Drab (new for the year), Common Quaker, Early Grey, 2x Hebrew Character, and a Red-green Carpet, also NFY.

Red-green Carpet (Chloroclysta siterata) — Red-green Carpet, Chloroclysta siterata

The Red-green Carpet is usually on the wing in the Autumn, the males die, but the females can hibernate to lay eggs in the spring. To my eye, they generally look green with some spots and patches at this time of year, but the autumnal ones are more obviously green and red…ish.

The “carpet” part of its name refers not to the notion that its larvae eat carpets, rather than in the 1700s when species were first being classified and named, the early entomologists and indeed the Lepidopterists perceived the beauty of these creatures and equated their colourful patterns and markings as being like the luxury items carpets were at the time.

The Red-green Carpet moth is a beautiful and fascinating species of moth that belongs to the family Geometridae, which includes many other species commonly known as “carpet moths”. This moth is found throughout Europe, including the United Kingdom, where it is one of the most common species of carpet moth.

Like all Lepidoptera, the species undergoes a complete metamorphosis, with four distinct life stages: egg, larva, pupa, and adult. The eggs are laid on the leaves of the host plant, which can include a wide variety of deciduous trees, most commonly oak and rowan. The larvae, which are often called “inchworms” (US usage) because of their distinctive way of moving, measuring the earth…hence geometers undergo several moults before pupating. The pupa is a non-feeding, transformative stage in which the larva transforms into the adult moth. Finally, the adult emerges from the pupa and begins the cycle anew by finding a mate and the females laying eggs.

Early Oak Piercer just for FUN

TL:DR – Pheromones are a useful tool for discovering what day-flying moths are in your neighbourhood.

As regular readers know, I do a bit of mothing…I have had a FUN lure, a pheromone lure aimed at attracting Grapholita funebrana. It’s been sighted in the garden for a couple of weeks with nothing appearing until 21st March 2023 at which point I was lucky enough to catch a couple of micro moths, Pammene giganteana (known to some unofficially as the Early Oak Piercer) not the target species but nice to see, nevertheless.

The micro moth Pammene giganteana (Early Oak Piercer) — The micro moth *Pammene giganteana* (Early Oak Piercer)

The larvae of the Early Oak Piercer feed inside oak-apple galls, which are themselves formed by parasitic wasps.

According to Anglian Lepidopterist Supplies from whom I bought this and other pheromone lures, the FUN lure has a long list of non-target species that might be drawn to it at different times of year, there may be others yet to be reported:

Glyphipterix fuscoviridella , Phyllonorycter quercifoliella, Grapholita janthinana , Cnephasia stephensiana , Ochsenheimeria vacculella, Epiblema costipunctana, Grapholita tenebrosana, Pseudargyrotoza conwagana, Dichrorampha aeratana, Acentria ephemerella, Argyresthia curvella, Endothenia gentianaeana, Hadena confusa (Marbled Coronet), Lymantria dispar (Gypsy Moth), Agrotis segetum (Turnip Moth), Tinea semifulvella, Pammene argyrana, Pammene aurana, Pammene giganteana, Pammene albuginana, Pammene obscurana, Pammene suspectana, Pammene fasciana, Amblyptilia punctidactyla

Pheromone moth trap — A simple pheromone moth trap. The lure is held in a receptacle above an funnelled opening, a moth attracted to the lure will commonly fall into the funnel and be unable to escape, ready for identification, logging, and release back into the wild unharmed.

British mothers in the early spring

TL:DR – Mothing is a simple, but educational and fascinating hobby. The data it accumulates can be useful scientifically.

I have lit up with a couple of different traps through the winter, but with generally disappointing results. There are not a lot of trees in our neighbourhood, which I suspect is the reason we don’t get a huge number of moths. That said, very few moth-ers see lots of moths in the gardens during the winter months.

15Watt Heath type, portable moth trap in place and ready for lighting up time

I put out my “spare” Heath trap last night. It is basically an ultraviolet fluorescent tube supported above funnel on top of a plastic box. The UV tube attracts nocturnal moths. They flap about a bit around the tube, perhaps bash into the vertical plastic vanes, and drop into the box. The box contains a load of cardboard egg cartons and the moths will generally secrete themselves among the hollows once they’re bored with chasing the light.

Come the morning, the diligent moth-er will be up at dawn to identify and count the moths trapped overnight, record the data ready to send off to the county moth recorder for scientific analysis along with records from others. The moths themselves are released off-site into bushes and undergrowth, preferably near dusk, and safely carry on with their lives.

Quick phone macro shot of the Hebrew Character moth and in the background an Early Grey

The haul from the moth trap, if you could call it a haul, was the biggest and most diverse of the year so far. Four moths of three different species. A micro moth known as Diurnea fagella, which arrived about three weeks earlier than this in 2022, a second Hebrew Character, and the first Early Grey, two of them. At the height of summer, I expect to see a couple of hundred moths of 60 differents species on a lighting up night. But, it was just 7 Celsius overnight, that and other factors at play can keep numbers down until well into the spring it seems.

Now, you are perhaps wondering whether this is ethical or even worse cruel and there are definitely arguments for and against. But, what is definitely known is that we need to monitor the natural world to know anything about it with the aim of helping protect it, conserve, and restore. The moths are just one indicator of whether a location is environmentally healthy. They are often expert pollinators. They and their larvae also provide food for birds, frogs, and various other animals. They are themselves beautiful and fascinating creatures and deserve their place in the world just as any other living creature. I wrote on this issue about a year after I started mothing.

Oh, and if you were worrying about your woolen carpet and your three-piece suit, there are actually something like 1500 different species of moth in the UK, and only one or two species have larvae that eat textiles.

Incidentally, it was some of the names that first drew me to mothing. The one I mentioned above, Hebrew Character is fascinating and closely related etymologically to the Setaceous Hebrew Character.

First BLANK of the winter

Fellow mothers, those who light up in the hope of seeing interesting nocturnal Lepidoptera will know only too well the feeling of disappointment when they check their trap the morning after the night before only to find not a single scaly-winged friend within. A BLANK.

Last night was wet and chilly, early evening it had been dry, cloudless, and chilly, with a bright moon. The local primary school also did their annual fireworks extravaganza. None of this had any bearing on the moths, they just weren’t flying into the trap. So, my first BLANK since last winter. Null results are, of course, scientifically just as important as hits. It is logged in my spreadsheet and will be seen by our County Moth Recorder, Bill Mansfield, in due course.

Meanwhile, here’s a photo of the beautiful and enormous Blue Underwing, better known as the incomparable moth from Cliveden House, the Clifden Nonpareil. Came to my garden in September 2020.

#TeamMoth #MothsMatter

ChatGPT words about mothing:

Moth trapping is a technique used by lepidopterists to collect and study moth species for scientific research. The most common method of moth trapping is the use of a light trap. A light trap is a device that uses a light source, usually a bulb or LED, to attract moths at night. Moths are attracted to the light and fly towards it, eventually getting trapped in the trap. Other techniques include pheromone traps, which can be used to attract day-flying moths. Also sugaring, which involves pasting a strong-smelling sugary, often alcoholic, mixture on to outdoor surfaces to attract moths that less interested in light sources.

Here are some tips for effective moth trapping:

Choose a good location: Moth trapping is most effective in areas where there is little to no light pollution. The trap should be placed in a location where it is easily accessible but away from human traffic.
Use the right equipment: A light trap should have a bright light source that emits light in a specific range of wavelengths. The trap should also have a funnel or cone-shaped entrance that leads to a holding chamber or container.
Check the trap regularly: Moth trapping should be done at night and the trap should be checked regularly to avoid overheating or overcrowding of the moths.

Why do moth-ers sometimes have blanks?

Weather conditions: Moths are more active in warm and humid conditions. If the weather is too cold or dry, the number of moths that are active and visible may be reduced.
Moonlight: Moths are known to be attracted to light, but they are more attracted to artificial light than natural light. If the moon is bright, moths may be less attracted to the light trap.
Migration: Some species of moths are migratory and may not be present in a particular area during certain times of the year.
Habitat destruction: If the habitat where the trap is located has been destroyed or altered, there may be fewer moths in the area.