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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.

Coleoptera
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.

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

Diptera
These online keys to various families of Diptera are managed by Paul Beuk, who also runs the excellent Diptera.info. You may need to register on Diptera.info 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.

Lepidoptera
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.

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

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

Arachnida
This German website has a key to European spider families.

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Evolving snails: launch of Evolution Megalab

Continuing today’s snail theme, today is the official launch of the Evolution Megalab, a project being run by the Open University where people can contribute to evolution research by surveying the Brown-lipped Banded Snail Cepaea nemoralis. There’s been quite a lot of publicity about it today, and it is part of the OU’s celebration of Darwin 200.

Anyone can take part in the survey, and the Megalab site has full instructions, along with associated videos (see below) and an identification quiz you can take to rate yourself as a Cepaea identifier. Cepaea snails have a long history as evolutionary study subjects, and the Megalab gives you the chance to add to this body of work. You can also see what historical records are held for your area.

For those with mixed feelings about snails, there is no need to hate Cepaea snails! They prefer dead or decaying vegetation and although they can be common in gardens they don’t do much if any damage.

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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.