Identifying invertebrates: downloadable keys


The previous post listed some identification keys that run online, as more-or-less interactive websites. This post includes some sites that have keys you can download (usually as pdf documents) and print out. See also my bookmarks on delicious.

Various groups
Some excellent materials, many produced by Brian Eversham, are available on the website for The Wildlife Trust for Bedfordshire, Cambridgeshire, Northamptonshire and Peterborough [link updated at October 2012]. These include keys to insect orders, grasshoppers and bush-crickets, water bugs, ants, beetle families, longhorn beetles and soldier beetles (plus other non-insect groups). NB that most of these are tailored to the Bedfordshire area, and do not necessarily include all UK species (the exception being the soldier-beetle one by Dr Mike Fitton, which does have all species).

Various resources, including an identification guide to grass moths (Pyralidae: Crambinae) compiled by Nick Asher, can be downloaded from the Berkshire Moth Group.

Some keys to selected groups of bees and ants are available from BWARS.

Dipterists Forum has produced some really good downloadable keyes, some of which are available only to DF members; these include a very well-illustrated key to Diptera families, a key to Scathophagidae (dung-flies and allies), both of these by Stuart Ball, and a version of Alan Stubbs key to hoverfly tribes illustrated with photos by Stuart Ball – Dipterists Forum is worth joining just for these, let alone all the other benefits!

Available to anyone is the set of draft keys to craneflies, by Alan Stubbs, and keys to stilt and stalk flies, by Darwyn Sumner.

The recently established Beetle News has included keys to various small groups of beetles in its first few editions, and they can be downloaded from the Amateur Entomologists’ Society.

Field Studies Council
This listing from the FSC includes many of their published keys, available to purchase, but also some older papers that are free to download, including Unwin’s key to Diptera families, and the now slightly out-of-date key to slugs by Cameron, Eversham and Jackson.

Identifying invertebrates: online keys


On Saturday 30 January, Roger Hawkins and I are running a workshop for the BENHS on using keys for insect identification. We’ll mostly be working with published hard-copy keys, but we’ll include some online keys as well. Below are some examples for various invertebrate groups.

I must admit that I don’t yet make much use of online keys. This is partly because I’m fortunate in having a good range of printed keys available to me, and I’m sure it’s also partly a case of ‘sticking with what I know’ rather than spending time learning the online ones (all keys require time spent on them to get familiar with their particular approach). However, I think there are still some problems with online keys, from the practical one of having to have a computer within easy view of your specimen or microscope, to more intrinsic issues about the ease of flicking through a book to compare different sections, as opposed to having to switch between different windows on a computer.

However, online keys are likely to become more widespread and will no doubt get better as time goes on, just as printed ones have (and continue to do so), and no doubt the two will be seen as complementary rather than an either/or choice.

See below for some online keys to try out. For a longer list (including plants and other groups as well as invertebrates) see my bookmarks on delicious, and let me know if there are any other good keys out there, or any thoughts you have on using online keys. A post on downloadable keys will follow.

Various groups
The most comprehensive set of online keys that I am aware of is the DELTA Intkey system. This requires you to download some software onto your computer, after which you can either download various individual keys, or run them from the web.

At the moment there is quite a wide range of keys available within this system, for various taxonomic groups (not just invertebrates) and different parts of the world, but for UK insect purposes they include:

Orders of insects, families of Coleoptera, families of Diptera, genera of Ephemeroptera, families of Hemiptera, families of Hymenoptera, families of Lepidoptera, genera of butterflies, genera of Geometridae, genera of Noctuidae, species of Phyllonorycter, species of Odonata, genera of Orthoptera, families of Trichoptera.

These are multi-access keys so that you can answer the set of questions in any sequence, and need only answer the ones you’re confident of – the system will endeavour to give you a best match of one or more names for your specimen. I’ve made most use of the family keys for Coleoptera and Diptera, but I have to admit they’ve not proved as helpful as I hoped, and I still tend to return to paper-based single-access (dichotomous) keys for backup. But it is always good to have additional keys available for comparison, and no doubt if I used them more I’d get more used to their idiosyncrasies and perhaps find them more helpful.

There are some draft online keys available on iSpot (part of OPAL), including a simple ‘key to minibeasts’ – this part of iSpot is still under development, and there’ll be more to come.

The Watford Coleoptera Group (click on “ID aids”) are making a range of identification aids available, some in the form of keys, some as notes on particular species or groups of species.

[added on 10 February 2010]
The Natural History Museum provides a very useful key to bumblebees.

These online keys to various families of Diptera are managed by Paul Beuk, who also runs the excellent You may need to register on to get full access to the keys. Some of these keys are online versions of existing printed keys, others are new (e.g. includes the best key I’m aware of for genus Sylvicola in family Anisopodidae).

Not a key, but some very helpful support for keys is provided by the Anatomical Atlas of Flies, from CSIRO in Australia. This is a truly excellent web implementation of a morphology diagram and glossary of names for parts of flies, using detailed close-ups of real insect specimens. But it needs a good broadband connection to work at any speed!

Mark van Veen’s Faunist is a Dutch site with keys to various families of Diptera, plus Odonata, Orthoptera and sea-shells. The latter three are in Dutch only, but most of the Diptera keys are in English. They are well-illustrated and easy to use, and I think cover most of the British species in the families included. Plenty of information about the species is given (but remember that this refers to the fauna in Holland, which will include additional species and different habitats/behaviours compared to the UK).

Some of these keys to robber-flies (Asilidae) by Fritz Geller-Grimm are applicable to the UK (others cover various parts of the world).

For those flies with larvae that produce leaf-mines (largely Agromyzidae, plus a few Anthomyiidae etc.) there are keys based on the foodplant on the excellent UK Fly Mines site.

Similarly, for leaf-mines of Lepidoptera try Barry Dickerson’s online key, on the British Leafminers website. This is largely based on volumes 1 and 2 of “The Moths and Butterflies of Great Britain and Ireland”, but with some additions and revisions. A very useful resource (but be aware of all the non-lepidopterous insects that also make leaf-mines, most of which are listed, but not keyed, elsewhere on the site).

Butterfly Conservation/Moths Count provide a simple key to day-flying moths.

There is a good identification key to Irish dragonflies and damselflies, but it covers males only, and not all UK species are included.

The Conchological Society provide some online keys and other identification notes for various groups of snails and slugs.

This German website has a key to European spider families.

Snail identification: new edition of FSC key


Robert Cameron’s excellent Key for the identification of Land Snails in the British Isles was published by the Field Studies Council in 2003, and a new edition came out towards the end of 2008. I was unable to resist getting the new one, despite being an infrequent recorder of snails who was quite happy with the old one! Was it worth it?

The new edition is not very different (e.g. 84 pages as opposed to the original’s 82, and this has only changed due to the inclusion of a few new references), but it does contain four additional species, some corrections and some updates to the nomenclature (scientific names), quite a few of which have changed. The four new species are:

  • Myosotella denticulata. This is very similar to M. myosotis, and they are both species of tidal standlines and edges of saltmarshes. Both key out at the same place, and Cameron doesn’t attempt to distinguish the two fully. Further information on separating these species is available in Roy Anderson’s 2008 checklist of UK non-marine Mollusca, which can be downloaded from the Conchological Society.
  • Balea heydeni. This has been split from the similar B. perversa, and it seems that the ‘new’ species B. heydeni is actually the commoner of the two in Britain and Ireland, so previous records of B. perversa will have to be classed as an aggregate of the two species unless they can be checked. Balea spp. can be found on trees and rocks (the first edition of the key rather intriguingly says that B. perversa [agg.] is often found in places with few other snails, but this descriptive text has been sacrificed for lack of space in the second edition).
  • Papillifera bidens. A Mediterranean species that has been introduced into Britain; the only confirmed records so far are from a National Trust property in Buckinghamshire. Superficially similar to other clausiliid snails but with a distinctive dark band and white spots running round the shell.
  • Cernuella aginnica. Another introduced species that has so far been found only in Kent, and is not thought to be widespread. It is very similar to the common C. virgata, and requires dissection to confirm (features described but not illustrated in the key).

The only one of these that people living away from the coast are likely to encounter is Balea heydeni, so if you already have the first edition you should be quite safe to continue using it. But if you’re keen to watch out for the latest introductions then the second edition is essential.

And if you don’t have the key at all I would recommend it to anyone with an interest in snails – it is a thorough and careful key, but very well laid out and easy for a beginner to get to grips with. I particularly like Robert Cameron’s introduction to using the key, which starts:

“Experience has shown that there are two extremes in reactions to keys. One is the expectation that a good key should lead simply to the right answer, even in the hands of a beginner. The other, sometimes expressed by experts, is that keys never work well, and that only face-to-face tuition by an expert works properly. The first view leads to frustration, or even despar. The second can have the effect of making identification an arcance professional preserve.”

Robert goes on to chart a middle course between these extremes, providing guidance on how to get the best out of using a key, and what limitations have to be borne in mind. He demonstrates this advice well in his own key.

new books


Had an enjoyable day at the AES Exhibition last weekend, great to catch up with loads of people I haven’t seen for ages. Some new books out too, including:

  • The latest (vol. 5 part 17c) in Mike Morris’s series of weevil keys for the Royal Ent Soc. These keys are becoming much more nicely laid-out and user-friendly since the Field Studies Council started producing them for the RES, and this new key is a great improvement over the keys in Joy, which is probably all most of us have had access to up till now. However, they’re still a challenging group, and not for the first time in this set of keys I hit a problem with a specimen that didn’t really fit the keys. Maybe it’s me getting it wrong of course, but I’ll need to check it next time I’m near a museum.
  • And also the latest in the series of Surrey wildlife atlases, this time on bees, by David Baldock. This covers all the solitary and social bees recorded in the county, and as well as the usual dot maps there are informative species accounts, a very welcome new key to bee genera (by Graham Collins), and a set of 48 superb colour plates. Highly recommended, available from Surrey Wildlife Trust.
  • A new AES book on the larger water beetles, by Peter Sutton. Nicely written text full of anecdotes and clearly showing the author’s enthusiasm for this group of beetles. Keys to the larger species and lots of background information.