Moth Identification (part 1). Helpful books, websites and other resources.

 

Moth identification can be a daunting business. With around 2,500 moth species in the UK alone it's hard to know where to start. Fortunately, there is help at hand. This blog post points you in the direction of the best identification resources for moth recording in the UK and Ireland. 

I cover four main information sources:

1. Moth identification books.

2. Useful websites.

3. Online discussion groups and other online advice.

4. Artificial Intelligence-based resources.

All have their own advantages and potential pitfalls. So, read on.

1. Moth Identification Books

This is a personal selection of the books that I have found most helpful. Others are available, and the absence of any publication from this list does not amount to any sort of criticism. It's just that I don't use it.

I have included links to the Atropos shop for most of the books covered (links open in a new window). This is simply for ease of reference: I don't get anything for it and other online bookshops are available, such as NHBS. It's always worth shopping around for deals and special offers.

The two Bloomsbury guides to (macro) moths and micro-moths

One of my key messages is that the more identification resources you use, the better. It always pays to have a few books to hand. However, if I was forced to choose the moth identification book that I have used most of all it would be The Field Guide to the Moths of Great Britain and Ireland by Paul Waring and Martin Townsend, with brilliant illustrations by Richard Lewington. This is now into its third edition (published 2017) - Atropos bookshop link here.

One (very) small complaint about Waring and Townsend, as it's usually referred to, is that the title is misleading. Strictly, it only deals with the larger moths - the macro-moths. I will deal with moth classification in another blog, but suffice to say at this stage that Waring and Townsend will cover most of the moths that a beginner will want to identify. And it's pretty comprehensive. Only a handful of recently recorded species aren't covered. This is an important point: many otherwise excellent insect identification books will include only a selection of species, which is understandable given the scale of insect diversity, but which risks misidentification because of the potential to ignore possible confusion species.

Given the success of the first edition of Waring and Townsend, it was always likely that a companion guide would follow covering the micro-moths. Phil Sterling (who is a leading light of our Dorset moth verification team) and Mark Parsons teamed up with Richard Lewington to prepare The Field Guide to the Micro-moths of Britain and Ireland. The second edition (here) came out in 2023. Unlike its macro companion, this doesn't aim to be comprehensive: 1286 species are covered (out of 1576), with 1012 species illustrated. This does mean that it's possible, even likely (given time), that a micro-moth will turn up that isn't in the book. However, such an event is unlikely to trouble anyone who is new to moth recording.

For the sake of completeness, I should add that certain groups of micro-moths (as well as a few macro-moths) cannot be identified from images alone: many species require the dissection of genitalia ("gen. det.") to confirm the species. As such, Phil and Mark set out a clear warning against trying to "shoehorn" every micro-moth into one of the species illustrated in their book.

Both of the Bloomsbury guides are available in hardback, but I have had no problems using paperback versions of them both. Having said that, I have backed them both with what the 1970s TV programme Blue Peter referred to as 'sticky-backed plastic', which has made them considerably more resilient. Without this, both would suffer from spine-cracking, especially the thicker micro book. As well as coffee spillages and the like.

Bloomsbury have also produced a condensed (and cheaper) version of the Waring and Townsend - the Concise Guide to the Moths of Britain and Ireland, now in its second edition. This also contains Richard Lewington's illustrations, but the text entries are reduced in size and (to my mind) usefulness. I bought the first edition of this book but, despite its user-friendly spiral binding, it has remained on the shelf. 

(In the same series as the macro and micro-moth books, Phil Sterling, Barry Henwood and Richard Lewington have also produced a Field Guide to the Caterpillars of Great Britain and Ireland. This is also excellent, but outside the scope of the present blog.)

Chris Manley's Photographic Guide

Excellent though Richard Lewington's illustrations are, I like to have a photographic guide to hand as well. My stand-by here has been Chris Manley's British Moths: A Photographic Guide to the Moths of Britain and Ireland. This is now into a third edition (here), but I'm still using the second edition. The photos in Chris's book are excellent and orientated consistently in order to aid comparison. It is a joy to look at. A huge advantage is that it combines macros and micros into a single volume. It's not fully comprehensive, but it does include an impressive range of species, including a few that don't make it into the two Bloomsbury guides already mentioned. The species accounts in this book are however extremely brief, so look elsewhere for more detailed identification pointers. (The second edition of Chris's book contained a number of errors, although an addendum was made available. It also has a terrible index! Hopefully, these problems have been addressed in the third edition?) 

 

James Lowen's Gateway Guide

A special mention should be given to James Lowen's A Gateway Guide to British Moths (here), the only book in this list that is explicitly aimed at beginners. It's another photographic guide, and the quality of the images is simply stunning. One innovative feature is the presence of numbered pointers on the photographs, which refer to particular identification features in the text - very useful.

In setting the book out, James has departed from the traditional taxonomic approach of the other books described above. Moths are ordered by flight season, and then grouped broadly by visual appearance. This means that moths from different families are often shown on the same page. Personally, I find this confusing, as I never know where to find anything, but then I'm not the target audience. I can see that it might work very well for someone who is new to moths and doesn't know where to start looking to find the species that they are trying to identify. I like the way that James has included some of the more conspicuous micro-moth species, as a "taster" to perhaps encourage further study. 

Obviously, this book doesn't aim to be comprehensive (it focuses on only around 350 species), but James has done a great job in selecting those moths that beginners will want to identify. It's worth having just for the quality of the photographs.     

My 'go-to' list of moth identification books also includes two slim volumes. Both appear at first to have a limited geographical basis, but both have proved invaluable to this Dorset-based moth recorder.

Not only useful in the North West! 

All moth recorders will tell you that pug moths are a menace. I don't find the illustrations in either Waring and Townsend or Manley's book to be as helpful as they should be. While there is a useful preamble to the pugs section of Waring and Townsend, the sheer number of species listed is a bit daunting. (For example, the section headed "Conspicuous dark spot in middle of forewing but no distinct whitish spot in trailing corner" gives you a list of over 25 possibilities.) In this case, the separation between text and images acts against easy usage.

In contrast, Brian Hancock's Pug Moths of North-west England (here) is a model of spaciousness and clarity. Obviously, its distribution maps are of little use outside its stated geographical area (Cheshire, Lancashire and Cumbria). But the photographic illustrations are excellent, and include (where appropriate) images showing variation both within a species and as a result of wear during the season. In some cases, comparisons are shown side by side. Almost all of the UK's resident pug species are covered, with only six omissions. These include Cypress Pug and Channel Islands Pug, both of which have turned up in my Dorset garden. As long as you bear that limitation in mind, this is a very useful volume. 

Useful outside Berkshire, too!

In a similar vein, the Berkshire Moth Group have prepared a superb guide to the Common Micro-moths of Berkshire. A second edition is now available (here), which I haven't bought yet (note to self: do this!). Although this guide makes no claims to be comprehensive, it has an uncanny focus on the more common species of micro-moth that are likely to turn up in your trap. The first edition, which I'm still using, covers just over 100 species; apparently this number has been doubled in the second edition. This is another photographic guide, with the photos also having numbered annotations to point out key identification features. Photos of similar species are presented side by side, which is particularly helpful, especially in the awkward Eudonia/Scoparia complex of micro-moths (Crambidae). 

Old school identification! (Now out of print)

For the sake of completeness, I should also mention my first ever moth identification book - Bernard Skinner's Colour Identification Guide to the Moths of the British Isles (2nd edition). Before Waring and Townsend arrived, this was a standard reference book for macro-moths. It contains photographs of set specimens, with separate text. I found it difficult to use, for three main reasons. First, the set specimens look unnatural in comparison with the usual resting position of moths. Second, the images have a rather poor resolution, although I understand that this may be a particular problem with the second edition. Finally, the supporting text contains only limited descriptions of key identification features compared to more recent identification books - even the Concise Waring and Townsend. But having said all of that, Skinner has one feature that the other books omit: by showing set specimens, it includes images of the hind wings for all species. 

Skinner now appears to be out of print, but can no doubt be tracked down second hand. I probably wouldn't bother to buy it now, but it remains a useful part of my identification armoury.

Addendum: Since I first published this post, it has been pointed out to me (thanks Paul C) that I missed out Sean Clancy's Moths of Great Britain and Ireland (link here - available at an enticing discount, at the time of writing!). I haven't used the book myself, but other moth recorders speak highly of it. And, as I say, the more identification resources, the better.

2. Useful Websites

There are a lot of moth-related websites out there, so this will necessarily be a selective look at the ones that I find most useful for identification purposes.

Dorset Moths - an example of a county moth group website

If you are lucky, a local moth group will have set up a website describing the moths of your area. This is usually a county, such as our local Dorset Moths website, but it may cover a larger area such as West Midlands Moths. If you are lucky, this website will contain specific identification advice, such as Phil Dean's guide to pug moths on the Devon Moth Group site (here). But even if it doesn't, there should be some information that is useful for identification. One feature that is really helpful for beginners, and found on many county websites, is a page showing the moths that are most likely to be seen at different times of the year in your local area. An example is the Moths By Month feature on the Butterfly Conservation East of Scotland Branch website (here). The local dimension is really important here: as a result of their wider coverage, the identification books listed earlier in this post can only give broad ranges for flight times.

Once you have a tentative identification for your moth, it is always worth checking to see whether

your local moth recording website has information on its status in your area. For example, the Dorset Moths website contains distribution maps, flight times, photographs and summary text for all macro-moths recorded in the county (but only up to 2019 at the moment). If your species looks like an outlier then you have either found something that is interesting and unusual or you've misidentified your moth. Trust me, it's usually the second of these! (But as a rider to that, I should stress that validated observations of species flying at unusual times or unexpected places are some of the most interesting and scientifically useful records.)

Turning to national websites, Ian Kimber's UKMoths contains a great range of images of both macro and micro-moth species. There's a "beginners' top twenty" of his most popular ID requests. However, the website's text doesn't include as much detailed identification information as many of the books listed above.

Chris Lewis's British Lepidoptera website also contains a gallery of images. Although of less relevance to the beginner, these include images of moth dissection and genitalia. Not that I've used it, but Chris offers a moth genital dissection service, for a fee.

Useful though these may be, the website that I use most often myself is actually German - Lepiforum. This is an amazing resource, despite a few drawbacks. First, it includes plenty of species that you won't get in the British Isles. Second, it's in German (which I don't speak); while the advent of automatic translation has eased this particular burden a bit, it's still a bit clunky when it comes down to technical vocabulary. Having said that, the website contains an extraordinary range of images, and is particularly useful for exploring variation within a species. It's also the best place to look in the happy event that you have found something that is new to the British Isles!

Although not aimed at beginners, Phil Sterling (via Butterfly Conservation) recently presented a series of four hour-long moth identification video sessions on YouTube. These give a lot of essential detail to help in separating the more confusing groups of moths - mostly macro-moths but a few micros as well (Phil's speciality). A link to the first of these videos is here.

3. Online discussion groups and other online advice.

Social media has many disadvantages, but it is a useful tool for moth identification. Facebook, in particular, is the home for online discussion groups where members can post images of moths and ask for identification advice. I use two in particular. First is the Dorset Moths Facebook group (here), for which I am one of the administrators. Set up by the late Terry Box, who pioneered the online face of the Dorset Moth Group, this now contains 640 members. It's a private group, but if you have a genuine interest in the moths of Dorset then you are very welcome to join us. We have many out-of-county members. There may well be other similar local groups out there.

Also on Facebook, I dip from time to time into the Pugs In Flight Tonight group (here), another private group but with a larger membership (currently around 1,200 members). As already mentioned, pug identification can be especially tricky, and this is often reflected by the diversity of views expressed within the group about some submitted photographs! However, a consensus is usually reached (but it can be quite entertaining when it isn't.)

(Although a bit of a diversion, I can't resist also mentioning the Moth Trap Intruders Facebook group (here) where the topic of discussion is everything except moths. I can't help being interested in the huge variety of other insects (and other things) that turn up my trap. My most unusual 'intruder' was a juvenile House Martin (below) - not that it needed identifying, of course.)

House Martin - an unexpected moth trap intruder - Dorset

Facebook groups can be really helpful when you're stuck on an identification, but it's worth giving a bit of guidance about their use. Simply posting an image and asking 'what's this?' or 'ID please' is likely to get peoples' backs up quite quickly. It is far better to show that you have at least tried to work out the identification by yourself. Although this risks potential embarassment from being corrected in public, this has happened to most (all?) of us, and is probably a better learning tool in the long term. And here's a plea to those more experienced moth recorders who provide assistance on these forums: when giving out an identification it really helpful to explain why you have reached that view. 

Obviously, it goes without saying that participation in Facebook groups (and other online forums) should be respectful, avoiding unpleasantness. My experience has generally been positive - moth people are nice people! - but unfortunate comments do get through from time time to time, sometimes inadvertently, sometimes not. 

Which neatly brings me on to Twitter (X). This can also be a useful tool for moth identification, particularly thanks to helpful people like Sean Foote who runs the UK Moth Identification Twitter (X) account (@MOTHIDUK). Sean identifies a bewilderingly large number of moth images online: if you use his services then how about giving him an online tip? 

Using the #teammoth hashtag on Twitter (X) will improve the chances of your post geting seen by the right people. 

The same hashtag will also work on BlueSky, where an online community is developing as an alternative to Twitter/X. You can find me there at @mikemoths.bsky.social.

4. Artificial Intelligence-based resources.

By this, I mean image-recognition systems which can analyse your photographs and make suggestions.

I'm covering two of these in this blog post - Google Lens and ObsIdentify. 

Disclosure: until now, I have used neither of these systems for identifying UK moths. However, I have found Google Lens to be useful when going through my moth (and butterfly) pictures from parts of the world where diversity is high and comprehensive field guides are hard to come by - most recently India (see other blogs on this site). The ObsIdentify app sat unused on my phone, but I see from various sources that more and more UK moth recorders are using it, so I have decided to try it out.

Obviously, neither of these systems can identify species that rely on evidence that doesn't appear in your image - such as those that need dissection. It shouldn't need saying, but I have noticed that a minority of recorders appear reluctant to disagree with a computer-generated identification. It is always worth bearing in mind that IT is only as good as the data that goes into it. 

On the face of it, Google Lens is a neat system that works on both laptops and phones. Simply click the square icon at the right of the search box (see above) and upload an image. Google will then present you with a large number of what it 'thinks' are matching images on other web pages.

For the purposes of this blog post, I tried using Google Lens to identify 25 of my own photos, including macro and micro-moths. I used photos of species which seemed to me to be fairly obvious identifications (such as Alabonia geoffrella, Brimstone Moth and Four-spotted Footman), as well as those that might appear more challenging (includiinng Eudonia delunella, Ringed China-mark and Common Lutestring), plus a few species that are rare  the UK (such as Grass Webworm and Blair's Mocha).

The results were ... mixed. Google Lens presents you with a large number of possible 'hits'. In the case of the more easily identfiable species, such as Brimstone Moth (below), the vast majority of these were pointing to the correct species. More of these were macro-moths, but some of the micros that I tried out, such as Green Oak Tortrix Tortrix viridana, also did well, presenting very few incorrect IDs. My non-scientific scoring system showed that six of my 25 species were identified almost unanimously (i.e. almost no incorrect websites came up), while the overwhelming number of hits were correct in a further nine species. 

Brimstone Moth - no problem for Google Lens

However, two particular problems arose even with these more easily identified species.

First, a lot depends upon the quality of your photographs. I tried to use images where the key identification features were easily seen. But what looks straightforward to me may 'appear' quite different to an AI system. Rather alarmingly, one of my Buff-Tip photos generated a blank screen containing the comment: "Warning: this may contain explicit images". I don't even want to speculate.

So, Google Lens health warning no.1 is: use clear and unambiguous photos.

Elder Pearl Anania coronata - not an American moth

My image of Elder Pearl Anania coronata (above) highlighted a further potential problem, in that prompted a number of hits for the similar Anania tertialis. This is a North American species that, in fairness, has previously been considered as a subspecies of A. coronata - so they are quite similar.  Google Lens seems very keen to suggest North American species, which I guess reflects where most of its users are based. So this is my Google Lens health warning no. 2: read the supporting geographical information on the relevant website carefully!

Rusty-dot Pearl Udea ferrugalis - Google Lens struggled

The remaining 10 images were dealt with less satisfactorily by Google Lens. The good news is that in all cases at least one link was shown that included the correct species. However, there were also a similar number, or in some cases (such as this Rusty-dot Pearl photo above) many more, incorrect links. This could lead to misidentification, although by carefully comparing your original photo with the range of images that are offered by Google Lens, it may well be possible to find the correct species.

In doing so, there is however a further possible pitfall. Google Lens appears to trawl through a wide of websites. Even on a short survey like this, it was quickly obvious that not all of them contain accurate moth identifications. (Also, beware links that show the correct image but with an incorrect moth name below it). So, Google Lens health warning no. 3 is: only refer to reputable websites when seeking identifications. The websites discussed earlier in this blog post can be relied upon.

The best thing about Google Lens is, therefore, that it narrows the field - which is very useful for an inexperienced moth recorder. But it does have limitations. Use it as a tool, but not as a definitive identification source.

  

Angle Shades - no problem for ObsIdentify

ObsIdentify is a phone-based app that aims (as it puts it) to "recognize nature in one click" (link here). I tried it out with an (admittedly rather small) selection of 8 species from this morning's trap. (Moth numbers are still low this year, as explained in an earlier post.) The results were impressive.

All eight species were correctly identified with either a 99% or 100% probability. For the record, these were: Angle Shades (above), Clouded Drab, Hebrew Character, Light Brown Apple Moth, Muslin Moth, Pale Tussock, Shuttle-shaped Dart and Waved Umber. All are fairly distinctive, so perhaps this wasn't the toughest test, although I did wonder how it would cope with Clouded Drab, which is quite a variable species. The app coped well with images that wouldn't have made the cut for this blog, including moths perched at various angles on egg boxes. It works best when the subject is in the centre of the image, which can be cropped after you have taken the photo.

So, surprisingly, I must give ObsIdentify the thumbs-up, at least on the basis of this limited test. But the caveats that I outlined at the start of this section remain. While it looks like an extremely effective tool, it cannot be relied upon as the sole means of identification. 

Conclusion

If you have made it this far then many thanks. I would welcome any comments, particularly if you feel that there are any useful identification resources that I have missed. Surely there must be? I can then update the blog post as appropriate.