Vive la différence: an Anjou moth trap

Four-spotted Tyta luctuosa - Anjou, France

France is our favourite holiday destination. An easy hop over the Channel from Dorset opens up a heady mix of superb food and wine, pastoral landscapes and fascinating places to explore. There's only one snag: of necessity, most of our recent trips have taken place during the summer school holidays - a time that's generally poor for seeing wildlife. And this year (August 2026) is no exception, with temperatures down here in the Loire Valley currently peaking at a toasty 39 degrees. Animal life is generally keeping its head down, and even the butterfly numbers seem low.

But there are still moths! For a UK-based recorder, France is an exciting place to run a trap. And the further south you travel, the better it becomes. Moths that are familiar from home turn up next to species that would be major rarities on the British side of the Channel, as well as ones that have yet to make it to our shores.

For the record, I should add that I am staying in a rental cottage (gîte) in a small village around 10km north-west of Angers (Maine-et-Loire - the historic Anjou region). Being unsure of how well-separated the garden would be from its neighbours, I arrived with my low wattage (6W) battery-powered Heath-style trap. To date, I have run it on two nights, which have produced a total of 67 species and 314 individual moths - reasonable numbers for a trap of this power and type. In this post I'm just going to run through some of the highlights. 

Moth trap ready for opening.

The sight of a Portland Ribbon Wave (below) on the outside of the trap is always a hopeful sign. This species is regular in my Dorset garden, although never common; now resident in the UK, it is largely restricted to the south coast of England, but spreading north. But in France it's pretty common: there were a total of 20 in my two traps here. Portland Ribbon Wave is double-brooded in France (there's only a single brood in England), its caterpillars feeding on plants such as Yarrow.

Portland Ribbon Wave Idaea degeneraria - Anjou, France 

Another locally common species here that would cause surprise - and perhaps alarm - in the UK is Oak Processionary Moth (below). There were 15 in my two traps. In Britain, Oak Processionary is both a rare immigrant, although numbers are on the rise, and a resident that was accidentally introduced. It is a major pest of broadleaved woodland; while oak is its preferred larval food plant, it can spread onto other species during large infestations. This caterpillars are best avoided, as contact can cause skin and eye irritations; this isn't something that I've experienced personally, but if it's anything like my Brown-tail larval encounter some years ago then it will not be pleasant.

Oak Processionary Moth Thaumetopoea processionea - Anjou, France

Sitting nearby was a Pale Shoulder (below), one of five in my two traps. This exceptionally smart noctuid is a rare migrant to British shores; it has yet to make it my garden, but I live in hope. While there is some evidence that it has bred in England, there is no record of successful overwintering. Even in France the species has a generally southern distribution, being considered a migrant in the north of the country. It is also an impressive bird poo mimic.

Pale Shoulder Acontia lucida - Anjou, France

Inspecting the trap more closely, I could hardly miss a massive crambid sitting on the rain shield - a Giant Grass-moth Ancylolomia tentaculella (below). I knew straight away that it was a new species for me, which was a bit baffling as I have trapped in France before and it was not something that you would easily miss. But such is the joy of moth trapping: you never quite know what's going to turn up. Sorting out the identification was a bit of a challenge, as my standard French reference (Robineau, 2011) only covers macro-moths. It needed some searching of the web (as always, there are some great images on Lepiforum), which revealed that this is a species where males and females differ in both appearance and size - a good example of sexual dimorphism, although not as extreme as those species (such as Winter Moth) where females are wingless. Anyway, here are the female and male:

Giant Grass-moth Ancylolomia tentaculella (female) - Anjou, France

Giant Grass-moth Ancylolomia tentaculella (male) - Anjou, France

The size difference is not really apparent from these photos: for reference, the respective wing lengths are around 12-15 mm for the males and 15-20mm for the females. There are only a few British records of the species, but here it was the commonest 'micro' moth with 23 in the two traps combined.

I've already teased my star species of the night with the opening photo of this post - my first ever Four-spotted (also pictured below). Although this is resident in Britain, it is nationally scarce, with a patchy distribution that includes Dorset (notably Portland) and scattered sites through southern and eastern England. The larval foodplant is Field Bindweed Convolvulus arvensis.

A quick word about its common name: while only two (or at best three) white spots are obvious when the moth is at rest, all becomes clear when the wings are open, the white hindwing band giving the impression of two more spots (below).

Four-spotted Tyta luctuosa - Anjou, France

I encountered one nectaring the following day in the gardens of Angers Castle (which is well worth a visit); I hadn't realised that this moth also flies during the day.

  

Another day and night-flier only turned up in my second trap of the holiday: the stunning Spotted Sulphur (below), one of three. Formerly resident in East Anglia, this is now considered extinct in Britain. If it is a migrant species, it is a staggeringly rare one: the last British record seems to have been in the 1960s. Like Four-spotted, its larvae feed on Field Bindweed; the absence of both species from the British Isles may well be as a result of agricultural intensification, although other factors could have come into play. It would certainly be nice to see it again on our side of the Channel.

Spotted Sulphur Acontia trabealis - Anjou, France

The balance of species in a French moth trap can often be very different from that at home. Several groups were completely absent from the two traps that I have run down here, for example hawk-moths, tiger moths and footmen. This may be an artefact of the type of trap that I'm using, or they just may not be around this part of Anjou at the moment. Or it could be linked with the heat wave that we are experiencing here. 

In fact, the three most common species that I recorded were all noctuids. Coming in at second and third respectively were Vine's Rustic and Heart and Dart, both of which would be equally as common back in Dorset in mid-August. But at the top of the list was another French speciality - Great Dart (below).

 

Great Dart Agrotis bigramma - Anjou, France

Great Dart is a bit of a whopper as noctuids go, with a wing length of around 20mm. The size separates it from most broadly similar species, with Turnip Moth (which turned up here as well) being the main potential confusion. One of the key differences is that Great Dart has two sets of pale cross-lines with dark edges. In Britain, Great Dart is considered a scarce and infrequent migrant, but you only have to cross over to Normandy (or indeed the Channel Islands) to find it appearing as a frequent moth trap visitor.
 

The next noctuid (below) was a bit of a puzzle, and set me off looking for new species before I realised that it's actually a different form of a familiar August arrival at home - Centre-barred Sallow. The patten gives it away, with that distinctive central cross-line that could almost have been drawn by a ruler. In the British Isles this usually has a dark purple central band set against a yellowish background. However other forms are equally common on the continent including this all-brown form unicolor. 

Centre-barred Sallow Atethmia centrago (f. unicolor) - Anjou, France

While some groups of moths were missing, others seemed if anything to be over-represented - particularly the pyralid family (Pyralidae). I'm always pleased to see the lovely Rosy Knot-horn (below) - aka the Rhubarb and Custard moth; while this turns up most years in my Dorset trap, it would be unusual if it was missing from a summer moth trap in France.

Rosy Knot-horn Oncocera semirubella - Anjou, France.

Its close relative the Tufted Knot-horn (below) is a migrant to British shores, although it may now have taken root as a colonist. It's certainly more common down here in central France, with three in my second trap. The tufts of raised scales near the thorax separate it from similar species: this is quite a tricky group to identify.  

Tufted Knot-horn Acrobasis tumidana - Anjou, France

And to finish off with something completely different, I'll leave you with one of the other interesting invertebrates that also found its way into the trap - this Chestnut Weevil (below) with its impressive rostrum (projecting snout). The species occurs across western Europe, where it is a serious pest of Sweet Chestnut trees. According to GBIF there are no British records. The 'by-catch' from overseas moth traps is often as interesting as the moths themselves (heresy!), and I have a few more species to sort out from my Anjou adventure. But those will have to wait.
 

Chestnut Weevil Curcilio elaphas - Anjou, France

References

Robineau, Roland (2011) Guide des papillons nocturnes de France. Paris: Delachaux et Niestlé.

Sterling, Phil and Parsons, Mark (2023) Field Guide to the Micro-moths of Great Britain and Ireland. 2nd ed. London: Bloomsbury.

Waring, Paul and Townsend, Martin (2017) Field Guide to the Moths of Great Britain and Ireland. 3rd ed. London: Bloomsbury.

Websites

Atropos - migrant moth totals

GBIF - species distributions

Lepiforum

Introducing Common Migrant Moths (part 2) - the next eight

Small Mottled Willow (above) has probably been Britain's most ubiquitous migrant moth this year. The arrival of 19 more in my trap over the past couple of days has prompted me to post the second part of this blog on our common migrant species. 

Part 1 (link here) looked at the seven commonest immigrants - the ones that UK moth recorders are most likely to encounter. The present post considers the next group of eight species that sit in that 'grey zone' between rare and common, although what that means in practice will depend on where you are trapping. Moth recorders on Britain's south and east coasts will generally get better numbers than those inland, but even down here in Dorset I am very happy when any of these species turn up.

The eight moths covered in this post all had 3,000+ British and Irish records between 2010 and 2019, taken from the Atropos website. This is compiled by Sean Clancy, who does a great (and unenviable) job keeping on top of the data using information from county moth recorders. Obviously, these numbers will now be out of date - this year's Small Mottled Willow influx may well move that species into the 'very common' bracket - but they still give useful pointers towards what's common and what's not.

[Note - this blog was updated on 26 July 2026 with additional text and images.]

Top of this group of eight is the Vestal (below), with 15,405 records from 2010 to 2019.

Vestal Rhodometra sacraria - Dorset 22.9.19

This is a lovely moth. Linnaeus named it sacraria (from 'holy' or 'sacred') either because its colours reminded him of priestly robes or its simple yet beautiful pattern suggested virtue or chastity. The early collectors who named it the Vestal were clearly thinking of the latter, which is both odd and yet typical of the whimsical nature of our common moth names. (Maintaining a chaste and virtuous existence will of course be the last thing on a moth's mind.)

Identification is straightforward. While the colours can vary (see below), the basic pattern never changes. When resting, the moth has an upright, tent-like posture that differs from many of the other members of its family (the Geometridae) that spread their wings flat or hold them together vertically.

Globally, the Vestal is a widespread species, occurring in Europe, Asia, Africa and South America. Early arrivals can breed in Britain, with 'home grown' second generation individuals adding to summer and autumn migrants. But there is little evidence of that they can successfully overwinter here. 

An interesting feature of the Vestal is that its colour depends on the temperature experienced by the growing caterpillar. The 'classic' look of a strong pink stripe across a light straw-coloured background (as in the above photo) suggests that the caterpillar lived through high temperatures, so this moth was probably an arrival from southern Europe. Duller colours indicate that its origin may have been further north. The darker example pictured below, an autumn arrival, may well have bred in England.

Vestal Rhodometra sacraria (darker example) - Dorset 27.10.22

Britain's migrant moth of the moment, the Small Mottled Willow, comes second on the list with 8,248 records 2010-2019, but the annual average is now surely higher. This species is well known for its irregular habits - it's either feast or famine, with large numbers arriving in some years while other years see hardly any. I trapped only 13 last year (2025), while my 2026 total to date is 228! 

Small Mottled Willow Spodoptera exigua - Dorset 12.6.25

At first sight, Small Mottled Willow is a rather non-descript member of the noctuid family. However, despite a wide variation in size (which we have certainly seen this year), they are easy to identify once you get your eye in. The pinky-orange oval and kidney mark are good clues, but it is the moth's posture that is the real give-away. When at rest, its wings are held in a similarly tent-like manner to the Vestal, and often partly rolled under the body, giving a generally narrow appearance. Pale Mottled Willow is perhaps the most likely confusion species, but that has wider wings that are held flat when at rest. 

Known also as Beet Armyworm, Small Mottled Willow is found from North America to Australia, and causes significant damage to crops in tropical and semi-tropical lands. Its capacity to trouble farmers in Britain is severely limited by its inability to survive the colder winters here. For the time being.

Third on our list is Scarce Bordered Straw, with 7,071 records 2010-2019. Given that this moth is more likely to be seen here than its close namesake the Bordered Straw (see later), its name is rather unhelpful - which applies to a number of other British moths, as it happens.

Scarce Bordered Straw Helicoverpa armigera - Dorset 1.9.24

Scare Bordered Straw is one of the more tricky moths to identify because it lacks any one obvious distinguishing feature. The fact that it's a variable species doesn't help. At first sight, it is a classic member of the noctuid family (see my blog on moth family ID here), with a chunky, rather thickset appearance and a flat resting position. Consistent features are the oval and kidney marks which have fine dark outlines and central spots. Also look out for the wavy black cross-lines and the dark outer band (at the bottom of my photos). Here is a more red-brown coloured individual:

Scarce Bordered Straw Helicoverpa armigera (reddish-brown colour) - Dorset 27.10.22 

Also called Old World Bollworm, Scarce Bordered Straw is a major agricultural pest in tropical and subtropical regions of Africa, Asia and Australia, as well as being found across much of Europe. Its caterpillars are however rarely seen in Britain.

Sticking with the noctuid family, our fourth species is the Pearly Underwing (below), with 5,663 records 2010-2019. Known also as the Variegated Cutworm, it is found in North and South America and East Asia as well as Southern Europe. As with the previous two species, Pearly Underwing is an agricultural pest in warmer climates.

Pearly Underwing Peridroma saucia - Dorset 17.6.26

Like Scarce Bordered Straw, Pearly Underwing seems at first glance to be a rather undistinguished moth. But although its pattern and colouration are variable, there are several distinctive features. First, it is a large moth, its size range overlapping with that of the familiar Large Yellow Underwing. Second, as the name suggests, its hindwings have a pearl-like translucence, although this is set against dark veins and a dark band around the edge - and getting the moth to show you can be a bit of a challenge. Don't expect to see a shining white hindwing. But the best identification character of all requires you to look at the moth from the side, which reveals a narrow ridge of scales like a Mohican haircut - strictly, the thoracic crest (below).

Pearly Underwing Peridroma saucia (side view) - Dorset 17.6.26

While three of the commonest immigrant moths to Britain are classed as micro-moths (see my previous migrant moth blog), only one of the present group of eight falls within that category. It's one of my favourite species - the Olive-tree Pearl Palpita vitrealis (below), after which this wildlife blog was named. There were 5,065 records of this species between 2010 and 2019.

Olive-tree Pearl Palpita vitrealis -Dorset 10.8.20

Identification is straightforward, as the combination of plain, translucent white wings with a brown leading edge (costa) appears in no other British moth species. While the wings of the Box-tree Moth Cydalima perspectalis are translucent, they usually have thick black edges - and the moth is much larger.

Olive-tree Pearl is a member of the crambid family, many of which seem to have a yearning to travel long distances; these include two very common migrants (Rusty-dot Pearl Udea ferrugalis and Rush Veneer Nomophila noctuella) featured in my previous blog and a number of much rarer arrivals to our shores. Primarily an old world species, Olive-tree Pearl is found in Europe, Africa and Asia: I have recorded it in India (Goa), where it was a nice surprise to see a familiar moth in such exotic surroundings.

Despite its name, the caterpillars of Olive-tree Pearl feed on a variety of species including Ash, privets, forsythias, Strawberry Tree and Summer Jasmine as well as Olive. To date, there are no records of it having successfully bred in Britain, although egg-laying has been observed. Once again, the moth cannot successfully over-winter here.

Heading back into the world of macro-moths, our sixth species is Bordered Straw (below), with 3,789 records between 2010 and 2019.

Bordered Straw Heliothis peltigera - Dorset 21.9.20

Bordered Straw is a helpfully distinctive moth. Despite some variation in its background colour (see below), the overall pattern of markings is generally consistent: a dark kidney mark contrasting with a lighter and plain background. Compared with Scarce Bordered Straw Bordered Straw looks 'cleaner', especially in its lighter forms. Note that there is an further confusion species - Eastern Bordered Straw: see the update added at the end of this blog post.

Predominantly an old world species, the range of Bordered Straw is centred on Southern Europe, North Africa and West Asia. Unlike the other moths described in this blog post, it is sometimes seen flying during the day searching for flowers. I spotted a day-flier on Grange Heath, Dorset last month (below), showing the dark band on its hindwing which is usually hidden when the moth is at rest.

Bordered Straw Heliothis peltigera - day flying at Grange Heath, Dorset 22.5.26

Like the Vestal, as already described, the background colour of Bordered Straw is affected by the temperature experienced at the larval (caterpillar) stage, with lighter individuals likely to have bred in warmer climates. Early arrivals to our shores can breed here, giving rise to a second generation that can appear darker than the first arrivals: compare the September individual above with one from in June (below) which was almost certainly a migrant arrival. However, the moth is unable to over-winter here.

Bordered Straw Heliothis peltigera - Dorset 25.6.25

Coming in at number seven, the Convolvulus Hawk-moth (below) is one of the largest moths found in Britain. It is of a similar size to the resident Privet Hawk-moth and only beaten by the massive Death's-head Hawk-moth, an extremely rare migrant species that has yet to find my garden (but I live in hope). There were 3,475 records of Convolvulus Hawk-moth between 2010 and 2019.  

Convolvulus Hawk-moth Agrius convolvuli - Dorset 6.9.16

While the plain and streaky wings of Convolvulus Hawk-moth are similar to those of Pine Hawk-moth, the size difference easily separates the two species - the wing length of Pine Hawk-moth rarely exceeds 40 mm while Convolvulus can reach 55 mm. That is in the size range of Privet Hawk-moth, which also has pink stripes on its abdomen. However, Privet Hawk-moth has a distinctly black thorax (not grey) as well as dark-brown forewings and (if visible) two black bands on the hindwings, all features that are missing from Convolvulus Hawk-moth.

In Britain, Convolvulus Hawk-moths tend to arrive late in the season with numbers peaking in September. Adults are particularly attracted by the nectar of tobacco plants (Nicotiana) and can be observed feeding on flowers at dusk. Some moth enthusiasts have this plant in their gardens for that purpose; I'm afraid that I don't, but I still manage to see a few Convolvulus Hawk-moths here in Dorset each year. 

Like the previous two species, Convolvulus Hawk-moth is restricted to the old world, and is distributed widely across Africa, Asia, Australia and Southern Europe - although most European records appear to relate to individuals that have travelled from Africa. Those arriving in Britain may well mainly be the offspring of these first generation migrants, hence the late arrival times. While the moth's larval foodplants (bindweeds, as the name would suggest) are frequent in Britain (especially in my garden), the climate appears too severe to allow it to over-winter here. 

 

Convolvulus Hawk-moth Agrius convolvuli giving a me sharp stare - Dorset 26.9.24

Which brings us to the last species in this brief survey - the Gem (below). Although this geometrid just meets my 3,000+ criterion (the 2010-2019 figure being 3,038 records), it has (for me) been the the most elusive of this group of migrants. It wasn't until 2024 that I finally saw one and, to date, I've only had two more records here (both in 2025). I have no idea why this species doesn't seem to favour my trap, and I'm trying not to take it personally.  

 

Gem Nycterosea obstipata (male) - Dorset 2.5.25

The Gem is not a very conspicuous moth, being slightly smaller than Garden Carpet. Unusually for a moth, the male and females have different wing markings (sexual dimorphism, in the jargon). The females have dark wings, with a distinct black dot edged with white - presumably the 'gem' of the common name. (All of my Gem captures have been males, so I don't have a picture of the female. However, there's a good image on the UK Moths website here.) Males have a lighter brown or orange-brown wings, with many cross-lines. While there is also a black dot, this usually lacks the white ring, although a lighter circle is visible in my image above. 

Primarily a European species, the Gem is another migrant that can breed, but not overwinter, in Britain. In Dorset, it can occur at any time between April and December; my three records were in April, August and November. While most moth migrants to our shores are more common in the south and east, the Gem seem to particularly favour these areas and has tended not to venture north of Yorkshire and Furness - or over into Ireland for that matter. Having said that, its British distribution increased significantly between 1990 and 2016 (Randle et al, 2019), so this migrant may become a more familiar sight in northern latitudes. And, I hope, in my Dorset moth trap. 

Right - this 'gang of eight' concludes my brief survey of Britain's most common migrant moths. As will be seen from the Atropos website mentioned above - or indeed any good field guide - very many more moth species reach our shores, but most arrive in much smaller numbers (sometimes only single figures). While I have been lucky to see a number of real rarities (perhaps the subject of a future blog), many more migrants have eluded my trap, which is both a matter of frustration (especially when other Dorset moth recorders have been more successful - you know who you are!) but also a useful incentive to go on searching. But be warned - hunting for migrant moths can become a bit of an obsession ...

Update - 26 July 2026. 

When I first wrote this post I omitted mention of an additional confusion species - the Eastern Bordered Straw Heliothis nubifera. This is because, first, it has been classed as extremely rare migrant to Britain and Ireland (only 39 records up to 2024 according to the Atropos website) and, second, I had never seen one so didn't have a photo to use. However, 2026 has been an extremely good year for Eastern Bordered Straw arrivals on our shores: I'm not sure what the current total is, but it must be well over 100 records. One finally turned up in my trap yesterday morning, so this is what it looks like:

Eastern Bordered Straw Heliothis nubifera - Dorset 24.7.26

While the kidney mark is similar in colour and shape to that of Bordered Straw, the rest of the forewing area is generally more richly marked, with brown blotches, better defined cross-lines and several black dots on the leading edge (costa).

As it happened, singles of both Bordered Straw and Scare Bordered Straw were also in trap, so I was able to picture all three together (below) - an uncommon sight for British moth recorders. 

Left to right: Scarce Bordered Straw, Eastern Border Straw and Bordered Straw - Dorset 24.7.26

References

Emmet, A. Maitland (1991) The Scientific Names of the British Lepidoptera: their history and meaning. Harley Publications.

Parsons, M. and Clancy, S. (2023) A Guide to the Pyralid and Crambid Moths of Britain and Ireland. Atropos Publishing.

Randle, Z. et al. (2019) Atlas of Britain and Ireland's Larger Moths. Pisces Publications.

See also the field guides and websites listed in a separate blog post (notably Waring & Townsend and the Dorset Moths website).

Atropos migrant moth totals are here.

Global range data is from GBIF.

Text and images (c) Mike Hetherington

Introducing Common Migrant Moths (part 1) - the Big Seven

It has been a slow start to the year for moth recording, but everything changed last night (22 May 2026) with the arrival of warm air from the south (likely from North Africa). Such conditions are ideal for finding migrant moths down here on the Dorset coast, and I approached the trap this morning with some anticipation. As well as bleary eyes: I was up at 4.20am, arriving only just before our local Robins and House Sparrows.

The final trap tally was almost 200 moths from 69 species. Seven of these species were migrants. Moth migration is a particular interest, and this morning's arrival gives me the perfect opportunity to look at the subject in a bit more detail. In this (and the next) post I'm reviewing the common migrant species that we get in the UK, several of which turned up here this morning. 

There's much to say about moth migration, but I'll keep it short for the present post. In summary, we are talking about those moth species that arrive, but do not generally overwinter, in the UK. While early arrivals may breed successfully, their offspring are unlikely to survive the winter months. As such, they are unable to establish permanent breeding populations. For the time-being. 

This caveat is important. Over the last 20-30 years, the British Isles have seen the arrival and establishment of several moth species (such as Jersey Tiger) who's status has changed from migrant to resident breeder. Indeed, British populations of many longer established species (like Large Yellow Underwing and Angle Shades) are regularly augmented by arrivals from continental Europe or further afield. In such cases it is impossible to tell for certain whether the moth in your trap has experienced a cross-Channel journey or just flown in from a local population, although weather conditions along with the presence of known immigrant species alongside them can provide useful hints.

So - which species are the known migrants? For a newcomer this is a bit baffling, but there is help at hand. The status of British moths is explained in the better field guides (see my blog post reviewing identification resources), and migrant species are considered in some depth by the Atropos journal and website. Atropos runs a 'flight arrivals' page where recorders can post details of new sightings, although I don't post on this as often as I probably should. For users of Facebook, Steve Nash runs the Migrant Lepidoptera (GB & Ireland) group, which carries news and images of migrant arrivals. There is a similar account on BlueSky.

OK - let's have a look at the common migrant species. These are spread across several moth families, suggesting that the tendency to migrate is either an innate Lepidopteran characteristic or has evolved separately many times. Now is not the time to speculate! Certainly, some families seem to be disproportionately represented in the migrant lists - notably the Crambid micro-moths as we will see. This and the next blog do not take a taxonomic approach. Instead, they focus on abundance, describing the migrant species that you are most likely to encounter. 

This blog post starts with what I'm calling the 'big seven' - the species that are so common that absolute numbers simply cannot be obtained. Some arrive in massive influxes: for example around 3 million Silver Y moths were recorded per hour on Shetland in 1996 (quoted in Randle et al., 2019). But please note that these are only 'big' in the sense of numbers. As we'll see, one species is very small indeed.

So let's begin with the Silver Y moth (pictured below and at the start of this post). This is found across continental Europe. Flying during the day as well as night, it is a fairly conspicuous species. Look for it nectaring on flowers during a sunny afternoon - as well as in the moth trap.

Silver Y Autographa gamma - Dorset 17.5.25

It's clear how Silver Y got its name. The combined shape and colour of the obvious Y-shaped mark are usually diagnostic, but bear in mind that there are a number of moths with a similar form and resting position that could cause confusion. Several are very rare migrant species (not covered in this post), but there are two common residents that need to be ruled out - Plain Golden Y and Beautiful Golden Y (below). In both cases the Y mark is usually split and lacks the silver sheen.

Non-migrant confusion species 1 - Plain Golden Y Autographa jota - Dorset 23.6.20

Non-migrant confusion Species 2 - Beautiful Golden Y Autographa pulchrina - Dorset 15.6.18 

Silver Y is a true migrant, in that the offspring of moths that have bred in Britain have been recorded undertaking a return migration to the continent in search of warmer winters (Chapman et al., 2002). While numbers in Britain have declined, its range has increased (a curious pattern found in some other moth species). Like several other moth migrants, Silver Y is arriving here earlier in the year as climate patterns change.

The second common migrant moth is even more conspicuous - the Hummingbird Hawk-moth (below). This is largely day-flying, although a few do turn up in moth traps. It is a real crowd-pleaser, buzzing around flowering plants and bushes in a distinctly hummingbird-like manner. Getting a photo can be a real challenge: they never seem to keep still.

Hummingbird Hawk-moth Macroglossum stellatarum in action - Dorset 12.6.15

Identification is straightforward: Hummingbird Hawk-moths are unlike any of our common hawk-moths and the combination of white, black, grey and orange colours - plus the distinctive flight pattern - is diagnostic. The distribution of this species within Britain has increased markedly over the last 45 years and there is recent evidence of adults being able to successfully overwinter here. This year, one was seen as early as February here in Dorset. Globally, the range of the species stretches from continental Europe right across to East Asia.

The next two common migrant species are both members of the same family as the Silver Y (the Noctuids), but lack its particular profile and markings: they stand out less from the many other species in that large family. Nevertheless, both have distinctive characters that enable easy identification.

Unlike many migrant moths, Dark Sword-grass (below) has shown a major decrease in numbers since the 1970s. Nevertheless, it is still recorded across much of Britain, although it remains unclear whether the species has successfully overwintered here. Last year it was the first migrant moth to turn up in my Dorset trap - on 21 February 2025, which seems unusually early for a cross-Channel arrival. But you never know. Globally. the species is widespread, occurring in South America, southern Africa and Australia as well as Europe, Asia and North America where it is most commonly found.

Dark Sword-grass Agrotis ipsilon - Dorset 16.3.23

Superficially, Dark Sword-grass looks like many other large noctuid species, but it has a particular diagnostic feature enabling easy recognition - a narrow black triangle ('dart') protrudes from the kidney mark (facing down in the above photo), with two more black darts pointing towards it from the end of the wing. See the enlarged image below:

Dark Sword-grass - detail of wing marking

The last noctuid in this list - the Delicate (below)- has a distinctly southern and eastern distribution in Britain. It is rare in Scotland and North Wales.

Delicate Mythimna vitellina - Dorset 7.6.17

The light (delicate?) tracery of wavy brown cross-lines on a lighter background is pretty much unique to this species, although the background colour can vary. Paler adults, such as the one pictured above, have been shown to result from more rapid development at higher temperatures - so have probably arrived from somewhere hot and dry like southern Spain. Globally, the species is restricted mainly to Europe although it has also been recorded in the Canary Islands.

The remainder of the 'big seven' are all 'micro-moths' - see another post for more about the differences between 'micro' and 'macro' moths. The first two lie within the Crambid family, which contains some of my favourite moth species.

At first sight, the Rusty-dot Pearl (below - from this morning) appears relatively undistinguished. However, once you have got your eye in, its characteristic warm orange-brown colour with (usually) darker oval and kidney markings coupled with a strongly triangular shape clearly point to this species. Globally, the species has a large range that extends from Europe to South Africa and Japan.

Rusty-dot Pearl Udea ferrugalis - Dorset 22.5.26

The second common Crambid migrant, Rush Veneer (below, also from this morning), is more variable in colour and pattern than Rusty-dot Pearl. Fortunately, its long and narrow shape cannot be confused with any other common British moth (although there is a similar American species). The one pictured below is quite light in colour: others can be darker. The species has a similarly wide global range to Rusty-dot Pearl.

Rush Veneer Nomophila noctuella - Dorset 22.5.26

The final 'big seven' migrant is anything but big! The Diamond-back Moth (below) is absolutely tiny, about 6-8mm in length. You can easily miss them in a moth trap. Yet this minute insect is one of the world's great travellers, turning up in every continent except Antarctica (although I bet that a few have turned up there as well that no-one has yet discovered). They fly both during the day and night.

Diamond-back Moth Plutella xylostella - Dorset 24.5.18

Identification is fairly straightforward (if you can spot them in the first place); in their characteristic form, the wavy-edged light patch on the back provides a clear contrast with the dark sides of the moth. Given their small size, some form of magnification is helpful to make this out.

Diamond-back Moths can arrive in huge influxes, and in some years are probably the most abundant of all of the 'big seven' migrants to Britain described above. For example, hundreds of thousands arrived in May 2000, probably from Southern or South-eastern Europe (Chapman et al., 2002). There were only five in my trap this morning, but to witness a mass arrival is an impressive sight that I have only experienced once - on the island of Inner Farne off the coast of Northumberland several years ago, where every bit of vegetation seemed to be dotted with tiny moths.

It's worth adding that Diamond-back Moths can be a serious agricultural pest. The Natural History Museum has published a short article about the species here.

Right - those are Britain's top seven most common migrant species. The next blog will look at those that are a bit rarer, but still turn up in sizeable numbers. Watch this space.

References

Chapman, J.W., Reynolds, D.R., Smith, A.D., Riley, J.R., Pedgley, D.E. and Woiwod, I.P. (2002). 'High‐altitude migration of the diamondback moth Plutella xylostella to the UK: a study using radar, aerial netting, and ground trapping.' Ecological Entomology, 27(6), pp.641-650. (link)

Chapman, J.W., Lim, K.S. and Reynolds, D.R. (2013). 'The significance of midsummer movements of Autographa gamma: Implications for a mechanistic understanding of orientation behavior in a migrant moth.' Current Zoology, 59(3), pp.360-370. (link)

Parsons, M. and Clancy, S. (2023) A Guide to the Pyralid and Crambid Moths of Britain and Ireland. Atropos Publishing.

Randle, Z. et al. (2019) Atlas of Britain and Ireland's Larger Moths. Pisces Publications.

See also the field guides and websites listed in a separate blog post.

Global range data is from GBIF.

Introducing Common Spring Moths

 

Oak Beauty Biston strataria - Dorset 23.3.26

If you are new to moth recording then Spring is a great time to start. Moth numbers are manageable, so you can proceed at a relaxed pace without the stress that comes with a big summer catch. Mornings are still chilly, so any moths that you do catch are likely to be docile and will wait patiently while you work out what you've got. All in all, Spring mothing provides excellent foundation for the more hectic days that are yet to come.  

A recent run of cold nights has discouraged me from running the moth trap, but yesterday seemed warm enough to give it a go - and I'm pleased that I did. A total of 45 moths from 10 species represents a good return for the garden trap at this time of the year. As it happens, many of Spring's 'usual suspects' turned up, which is a good excuse for a blog post.

Last night I used my normal 125W mercury vapour Robinson trap. We're in a small village about a mile inland from the Dorset coast, which is great for attracting interesting migrant moths in Summer and Autumn (one for a separate blog!), but is notoriously slow at delivering the goods on Spring's colder nights. This may be because the village sits on a cool north-facing slope, a problem amplified by the need to avoid dazzling our neighbours which means that I run the trap in a north-facing rear garden. 

Anyway, that's enough excuses! As I explained on a previous moth identification blog, the UK's larger moths (aka 'macro-moths') are dominated by two main families - the noctuids and the geometrids. I've described the key features of these (and other) families in that blog post (link here), but in essence the noctuids are generally thick-set and chunky, while the geometrids tend to rest more like butterflies, with their wings usually (but not always) spread open like the Oak Beauty pictured at the start of this post. Both are well-represented at this time of year, while other moth families may be harder to track down.

Noctuids

Three species tend to dominate the trap at this time of the year, all noctuids. First, the Hebrew Character (below), which accounted for almost a third of the moths in my trap this morning.

Hebrew Character Orthosia gothica - Dorset 23.3.26

The saddle-shaped black mark on the wings of this moth is the key identification feature. No other Spring-flying moth has this, although if you are using AI identification apps you need to be aware that there is a similar (and also common) moth of Summer and Autumn called the Setaceous Hebrew Character. If you want to know more about moth identification resources then have a look at this blog that I posted a couple of years ago. Hebrew Character moths are found across most of Britain and Ireland; they over-winter in a pupa (cocoon) and emerge to feed on the flowers (catkins) of willows and sallows. 

This food source is also the target of the second common Spring noctuid - the Early Grey:

Early Grey Xylocampa areola - Dorset 23.3.26

Early Grey moths have a marbled pattern that can at first appear confusing, but once you have got your eye in then it's easily recognised. Although a few other species appear superficially similar (such as Shears), their flight period usually will not coincide with that of Early Grey - which will be over by May. The Early Grey has a widespread distribution across most of England and Wales, but is more patchy in Scotland (outside the Central Belt) and Ireland.

The third common Spring noctuid needs a bit more thought. This is the Common Quaker:

Common Quaker Orthosia cerasi - Dorset 23.3.26

In many ways, Common Quakers are the classic noctuid moth. I use an image of one in my moth identification course to illustrate some the main wing markings that are so important for getting a successful ID. These are the oval and kidney markings on each wing (in the jargon these are the 'orbicular and reniform stigmata'), which are neatly outlined in white, and the conspicuous white cross-line (the 'postmedian fascia'). Common Quakers are frequent across most of Britain and Ireland, especially in woodland, and regularly turn up in garden traps. But do beware: there is a very similar species (Vine's Rustic) that can easily be confused for Common Quaker; however, Vine's Rustic flies later in the year. By the time that June arrives the Common Quakers should have disappeared.

Less common, but still frequently recorded in England and Wales (less so in Scotland and Ireland) is the Small Quaker:

Small Quaker Orthosia cruda - Dorset 23.3.26

Like its namesake, Small Quaker also has white-lined oval and kidney markings. However, they are smaller and less distinct than on Common Quaker, and there is often a dark splodge within the kidney. Also, the moth is generally lighter in colour and plainer in appearance. It's not really a looker, I'm afraid. As the name suggests, Small Quakers are usually smaller than Common Quakers, although both species are variable in size and there can be an overlap. Here they are side-by-side this morning; while you can make out the size difference, it's not exactly obvious:

Small Quaker (left) and Common Quaker (right) - Dorset 23.3.26

For the sake of completeness here, I'm adding in a moth that didn't appear last night (and in fact hasn't appeared here yet this year) but which is relatively common at this time of year despite experiencing recent declines in both distribution and abundance. This is the Powdered Quaker (the photo is from last year):

Powdered Quaker Orthosia gracilis - Dorset 3.4.25

The key identification feature here is the generally speckled appearance, which is usually obvious despite some variation in the background colour - although most of the ones that I see are the dirty creamy-grey colour shown above. Powdered Quakers are found over most of England and Wales, but in Scotland are more common in the south and west. 

The common English names of the UK's moths are a source of much interest. They can be quirky (for example the Mother Shipton), descriptive (the Silver Y springs to mind) or just plain bizarre (like the Ni Moth). Many are rooted in history, dating back to a wave of moth-naming in the 1600s and 1700s. The various Quakers surely date from this period.

Unfortunately, such names are unreliable when it comes to understanding how moth species are classified and related to each other. If you've noticed the scientific names on this blog's photo captions, you will see that Common and Small Quakers are closely related as well as similar in appearance: they are part of the same genus (Orthosia). But so is the Hebrew Character, which has very different wing markings. The final two noctuids that I'm introducing in this blog underline this confusion. First is the Clouded Drab, which is also in the Orthosia genus:

Clouded Drab Orthosia incerta - Dorset 23.3.26

If it could have a say in the matter, the Clouded Drab would probably be less than chuffed with whoever decided on its common name. Although rather plain, its colour and patterning can have a subtle charm. While its appearance can be variable (the scientific name incerta means 'not fixed'), Clouded Drab can normally be recognised by its large size (bigger than all of the previous moths), rather pointed wing tips and the generally muted oval and kidney markings (although these can be more obvious than in the example pictured above). Two similar species (Lead-coloured Drab and Northern Drab) are much more localised and I have yet to see either in my trap. Clouded Drab has a similar distribution to Common Quaker.

My last noctuid is Twin-spotted Quaker (below), which despite its name is not in the Orthosia genus:

Twin-spotted Quaker Anorthoa munda - Dorset 23.3.26

This is also a large moth, similar in size to Clouded Drab, and as its name suggests is usually recognised by the presence of two obvious black dots near to the outer edge ('termen') of the wing. In the example that I caught this morning (above) these dots are actually orange - and not very obvious. But they are there if you look. I should explain at this point that the way that moth wings are described can be confusing to the newcomer. By convention, the base of a moth's wing is the point at which it joins the moth's body (thorax), which is usually at the top of most moth images. The outer edge (or termen) of the wing is therefore the bit that's furthest away from the base, which in this case is at the bottom of the photo. It does make sense, but it also needs a bit of getting used to. Anyway, Twin-spotted Quakers are fairly common in England and Wales and seem to be spreading north in Scotland.

Geometrids

Geometrids (or geometer moths) seem to be much more scarce in the Spring months. Only three species have turned up here so far in 2026, although as I've already said it has been a quiet start to the year. The most spectacular is undoubtedly the Oak Beauty pictured at the start of this blog. Here's another one from a couple of years ago:

Oak Beauty Biston strataria - Dorset 22.1.24 (an early arrival)

Oak Beauty is one of the most sought-after Spring arrivals, and it's always nice to see. The two reddish-brown jagged bands across the wings are found in no other UK moth species. Despite the name, the caterpillars (larvae) of this moth feed on a range of broadleaved trees and shrubs - not just Oaks. They are widely distributed across England and Wales but may be spreading into Scotland. It is one of several moth species that are showing a curious trend: while overall abundance is decreasing, their distribution is widening.  (There is more about this in my blog post on insect decline - link here.)

Similar in shape, but not markings and colouration, is Brindled Beauty (below). Unfortunately I'm still waiting for this one in 2026, so here's an example from last year:

Brindled Beauty Lycia hirtaria - Dorset 3.4.25

Brindled Beauty is widespread across Wales, southern and central England and the Scottish Highland, but appears less common in northern England and southern Scotland - a curiously scattered distribution. Its dark markings separate it from the male Pale Brindled Beauty (below - another one from last year):

Pale Brindled Beauty (male) Phigalia pilosaria - Dorset 14.1.25

Pale Brindled Beauty is distributed more widely than its darker namesake, but both species have suffered significant declines in abundance (83% and 78% respectively). One significant difference between the two species is that Pale Brindled Beauty females are flightless; the females have no wings and therefore have very limited mobility, a characteristic that is shared by a number of other early-flying species including the March Moth (see below). 

One of the most distinctive Spring geometrids is Early Thorn (below), pictured last month. The Thorns are some of the few UK moths that hold their wings vertically when resting.

Early Thorn Selenia dentaria - Dorset 23.2.26

There are eight UK Thorn species of which only two appear in the Spring months. Early Thorn is the most common and widespread, although it is even more frequent during its later second generation in July and August. The formal term for such double-brooded species is 'bivoltine'. The other Spring-flying species is the arguably more spectacular Purple Thorn (below); I don't see many of those here, so have had to dig into the archives for an image from 2022.

Purple Thorn Selenia tetralunaria - Dorset 16.4.22

The coloured banding on the underside of Purple Thorn's wings is strikingly different to that of Early Thorn. If you compare the two images you will see that small white crescent 'moons' can be seen on the underside of each of Purple Thorn's four wings (hence tetralunaria) while only two (on the hindwings) are seen on Early Thorn. (The much rarer Lunar Thorn also has four 'moons', but flies a bit later in the year.) But the key distinction is that Early Thorn is the only UK Thorn species that holds its wings pressed together; in Purple Thorn, and the others, a gap is maintained.

Very different in appearance from most other geometrids is the March Moth (below), which despite its name can appear as early as January. The first male of the year turned up here at the end of February, but this image is from one observed last year. Like the Pale Brindled Beauty (see above) the females of this species cannot fly.

March Moth male Alsophila aescularia - Dorset 23.2.25

Erebidae

All but one of the larger (macro-) moths that I have trapped this year belong to the two main families described above. The exception is the beautiful Herald (below), which I discovered sitting on a garden chair next to the moth trap this morning. Fortunately it had escaped the attention of the local Robin. 

Herald Scoliopteryx libatrix - Dorset 23.3.26

Claiming this as a Spring moth is a bit of a cheat, as the Herald flies during most months of the year. However, unlike all of the species described above, it overwinters as an adult, finding cover in a quiet location such as a natural cave or somebody's garden shed before emerging around March. Historical data shows that the average time of emergence has moved forward several weeks since the 1970s, yet another climate change-related effect.  

That concludes my brief run-through of the most commonly-seen Spring moths. Numbers of species, and of individual moths, will start to rise as the year progresses, so I doubt whether I can attempt another seasonal survey. But more moth blogs will be coming. In the meantime, happy mothing!

References

Identification references used are set out in more detail in a separate blog - link here.

Distribution and abundance information is from the excellent Atlas of Britain and Ireland's Larger Moths (Randle et al, 2019).