Biodiversity and ecology in the Australian bush

Identifying invertebrates

insects, spiders and more

Identifying invertebrates is a hugely rewarding activity. Insects alone far (far!) outnumber vertebrates, both in terms of number of species and the sheer number of individuals. They are everywhere, living all kinds of lives. Add the spiders, and this diverse array of life is enough to keep even the keenest naturalist busy for a lifetime.

As must be evident from our website, we find invertebrates endlessly fascinating. And the importance of their roles in the ecology of the forest cannot be overstated.

However, identifying invertebrates does present particular challenges:

The limited Field Guides available

Field Guides are available for only some invertebrate groups. Such guides are valuable for identification to family and often to genus level. For some smaller groups there are even guides comprehensive to the level of individual species. We are fortunate that CSIRO continues to support the publication of such resources, regularly adding new titles on Australian invertebrates.

The many undescribed species

There are many species that have yet to be fully described scientifically. That is, they don’t have a scientific name and will generally not appear in field guides or identification keys.

Their small size

Many invertebrates are tiny, and the morphological differences between species are often only evident under a microscope.

Their individual variability

In some groups, there is considerable variation between individuals. Not only sex-specific or age differences, but also differences in size and colour depending upon their environment or conditions for growth and development.

Invertebrate anatomy has its own language

For people new to biology, there is a vocabulary to learn in order to make sense of even the simplest invertebrate descriptions. Fortunately, there are many resources to help – glossaries and diagrams, online and in field guides.

 

Tip 1 – Identification to family or genus is a worthwhile goal

For the reasons listed above, identification to species may not be possible, or may be impractical. Identification to genus, or even just family, can be enough to provide access to a wealth of information about the animal’s biology and ecology.

 

Observations and data

 

Photography

We find photography an indispensible tool for invertebrate species identification. It means we usually avoid the need to collect an insect or spider, or if collected we can release them after we take a few shots. Just as valuable, however, is the ability to view detailed, enlarged images on a computer screen while we pore over identification resources.

We are fortunate in our ability to employ a wide range of imaging systems. Our telephoto ‘bird lens’ works really well for large or skittish insects like butterflies, wasps and dragonflies.  We use macro lenses for field photography of smaller, slow moving invertebrates. And we have dedicated photography lenses and equipment for specimens under the microscope, drawing on our professional experience as biologists in past lives.

 

Tip 2 – Take lots of photos, and from all angles

Sometimes it is the most unpromising looking photograph that provides the vital piece of information needed for identification. And once you become familiar with a group, you tend to know what features to try for. For example, with dragonflies I always try to get shots of the wing venation and also the colouring on the abdominal segments.

 

Microscopy

There are two main types of microscopes widely available for home use: ‘compound’ and ‘dissecting’ microscopes.

Compound microscopes are not very useful for invertebrate identification, unless you are interested in animals that are truly ‘micro’, and invisible to the naked eye. Compound microscopes are used to view VERY small structures, and such objects need to be mounted on a glass slide. Light is shone up through the object, so the material needs to be transparent. Many people will have used such microscopes at school or university to examine plant cells or perhaps their own cheek cells.

Dissecting microscopes, on the other hand, are extremely useful tools. They have a large working area and light may be shone from above, not through, the object. Therefore they can be used to examine intact specimens, including living animals and plants. (Note that in commercial product lists, dissecting scopes are sometimes called 'stereo-microscopes', although strictly speaking this term refers to the number of eyepieces not the type of scope).

 

Tip 3 – Invest in a dissecting microscope

Reasonable quality microscopes are actually quite affordable (e.g from $200-$300). If you plan to get serious about insect identification, or you are working on plant material, a dissecting microscope is invaluable. A bright desk lamp can be used as the light source, particularly if the lamp can be positioned to direct the light onto the microscope stage from a range of angles. 

 

Raising larvae

Many insects have larval stages that have a completely different appearance to the adult. Butterflies, moths, beetles, and wasps, are examples of such ‘holometabolous’ insects. Collecting and raising larvae through to the adult stage is one way to help identify the species. Lepidopteran larvae (the ‘caterpillars’ of butterflies and moths) are particularly amenable to raising, so long as they are supplied with their specific host plant food.

During their development, many caterpillars change their appearance quite dramatically. For this reason, raising caterpillars through to the adult can sometimes be the only way to identify the species.

To read more, see our 14/9/17 blog post Studying lepidopteran life histories.

A cautionary note regarding collection

From many locations, including all national parks and nature reserves, collection of biological materials is not permitted. Always check the laws in your area before removing any plants or animals.

 

Key resources

 

Atlas of Living Australia (ALA) www.ala.org.au

Described as ‘Australia’s national biodiversity database’, the Atlas of Living Australia is an extraordinary resource. It brings together species records from a range of sources, including from museums, research collections, and from citizen-science projects. The structure of the site enables viewing of records and photos at all taxonomic levels, and we routinely use the site as a way to check we are on the right track with our identification of invertebrates.

Cautionary note: although the ALA site is progressively checked and moderated, not all records are accurate. Therefore, we always look for additional sources to ‘triangulate’ any identification.

Ideally, we would consult the original species description and any subsequent taxonomic reviews before conclusively identifying a species. In practice, however, we often rely upon slightly less rigorous means. For many invertebrates, we can feel sufficiently confident of their identity by using a combination of field guides, other relevant reference books, and online resources such as ALA.

 

Tip 4 – Once you have a possible identification, search ALA

Use the gallery pages to compare your specimen with the ALA images. Check the map to see if there have been collections of that species (or genus) in your area. And use the 'classification tab' to step back through progressively higher taxa - it may be that your specimen is actually a better match with a relative of the species you are currently investigating.

 

Pooling knowledge through citizen-science

The emergence of citizen-science is a boon for naturalists. There are numerous online projects designed to encourage the sharing of observations and knowledge about the biological diversity of Australia. Some projects focus on a subset of organisms (e.g. plants, native bees, flies, orchids, etc). Others collect information on all organisms within a region (e.g. the 'Coastal Wilderness' of southern NSW) or a specific site (e.g. Grampians National Park). 

We have recently become active contributors to the Atlas of Life in the Coastal Wilderness, a citizen-science initiative that gathers knowledge about the biodiversity of our local region. Not only are we using the resources of the site as a guide to species identification, but we are also contributing our own observations and images. 

Bowerbird.org is a great place to search for similar citizen-science projects. The website has been designed by Museum Victoria and the ALA as a place where individuals can participate, form online groups (i.e. 'projects'), and generally discuss species identification and observations. (And, no, it's not about Bowerbirds - it covers all kinds of Australian animals and plants).

As with the Atlas of Life in the Coastal Wilderness, Bowerbird projects provide a conduit for contributions to the national ALA database. 

 

Tip 5 – Search Bowerbird.org for projects of interest

Search for a relevant project, then scroll through the images and identification comments. Alternatively, search for the species or genus that you think your animal might belong to. Most project groups include some members with expertise - professional taxonomists, researchers, or experienced amateur naturalists - who provide suggestions and assistance with identification. Their comments on existing posts can be very helpful in your own identification search. Or, of course, you can seek help directly by joining such a group and uploading an image of your specimen.

 

References books & field guides - a few examples

 

All insect orders

CSIRO (ed.). (1991). The Insects of Australia. A textbook for students and research workers. 560 + 600 pp., 2 volumes. (Carlton: Melbourne University Press).

An authoritative and comprehensive text covering all 32 orders and 661 families of insects* in Australia. Some prior familiarity with insect biology is helpful, as the detailed sections in this book are quite technical. However, the introductory text for each order is accessible, and the drawings alone can provide valuable clues to family identity.
(*includes 4 non-insect orders e.g. Collembola)

Individual insect orders or groups

Common, I.F.B. (1990). Moths of Australia. CSIRO Publishing. Out of print, but available as an eBook.

Hangay, G. & Zborowski, P. (2010). A Guide to the Beetles of Australia. (CSIRO Publishing, Collingwood).

Marriott, P., Kallies, A. & Hewish, M and others (2011-2016). Moths of Victoria. Parts 1-7. (Entomological Society of Victoria).

Through the Entomological Society of Victoria, a group of Society members and associates compile this ongoing series describing the moth species found in Victoria. As moths don't respect political boundaries, and as we live only a short distance to the north of the NSW-Victoria border, this resource is extremely useful for us.

Moulds, M.S. (1990). Australian Cicadas. (New South Wales University Press, Kensington).

Orr, A. & Kitching, R. (2010). The Butterflies of Australia. (Jacana Books, Crows Nest, NSW).

Comprehensive, with excellent drawings and ecological information for the nearly 400 species of Australian butterflies.

Rentz, D. (2010). A Guide to the Katydids of Australia. (CSIRO Publishing, Collingwood).

Theischinger, G. & Hawking, J. (2012). The Complete Field Guide to Dragonflies of Australia. (CSIRO Publishing, Collingwood).

Comprehensive, with detailed descriptions and photographs of all 324 species of Australian dragonflies and damselflies.

Zborowski, P. & Edwards, T. (2007). A Guide to Australian Moths. (CSIRO Publishing, Collingwood).

Spiders

Framenau, V.W., Baehr, B.C. & Zborowski, P. (2014). A Guide to the Spiders of Australia. (Reed New Holland Publishers, Sydney).

Whyte, R. & Anderson, G. (2017). A Field Guide to Spiders of Australia. (CSIRO Publishing, Clayton South).

Covers all families of Australian Spiders in an accessible and highly readable field guide. The book also includes general tips and advice on species identification. It contains ecological information for each family, and more than 1300 excellent photographs - most of which are identified to species level. We find that the book often enables us to identify our specimen to at least the genus level, particularly for the more common or distinctive spiders.

 

Tip 6 – Build or access a library of reference books

There is something about a book. We make extensive use of the internet (of course), but we still nearly always reach for a physical field guide if we have one, flicking through to look for clues. And we still consult seminal texts such as CSIRO's Insects of Australia for a more technical overview.

 

Online identification guides

 

Don Herbison-Evans’ website Australian Caterpillars and their Butterflies and Moths 

We make extensive use of this site, which has a wealth of images and life-history information collected from a large number of individuals and organisations over many years.

Arachne.org

We have been trawling this website for several years - and now it has become a physical field guide! Robert Whyte and Greg Anderson used their Arachne.org project in the development of their 2017 book. We have the book - we still use the website.

Framenau's Flickr collection

Volker Framenau can be considered the authority on Australia's wolf spiders (Family: Lycosidae). He is currently working on a comprehensive review of the family, and a book should appear soon. In the meantime, his collection of images across a range of spider families is certainly worth a look - as is his Lycosidae website.

CSIRO Entomology - Insects and their allies 

A basic overview of the key invertebrate groups that can be surprisingly useful, even for reasonably experienced naturalists. 

NSW Government (DPI) - ASCU

This site provides illustrated keys for the identification of two groups of hemipterans: the aphids (Family: Aphididae) and the large group containing the leafhoppers, planthoppers and treehoppers (sub-order: Auchenorrhyncha).

AntWiki 

A Wikipedia-like page run by ant researchers, for ant researchers. And it's all made available and accessible for use by the general public. Definitely useful when identifying our local ant species, as Australia certainly features. It turns out that Australia has a greater diversity of ants than almost every other country - 27 per cent of the world's genera are found right here! 

 

Tip 7 – Don't be too proud to simply 'Google' it

You never know what you'll find with a web search. Once you have a candidate identification, it is always worth typing the name into a search engine. 

And sometimes we use this strategy even before we have a candidate identification!

Imagine you discover a huge, red stick insect. Or at least that's what you think it is. Unless you have a Phasmid field guide handy, there is much to be said for simply typing 'huge red stick insect Australia' into a search engine, and see where it leads. More than once this strategy has helped us get to first base with a possible genus or even species name ... and from there we can start using some of the more targeted resources and strategies described above.

 

Tip 8 – Finally, be prepared to get it wrong - it's OK!

No matter how thorough you are with your research, it is always possible to get it wrong. That is simply the nature of the activity. Even the experts often have to revisit and revise their identifications.

Our own rule-of-thumb is this. If, on the weight of several lines of evidence, one candidate identification is most strongly supported, we are willing to call it. However, if there is nothing favouring one possibility over another, we stop at the taxon above. That is, if it could equally be species A or species B, we will simply call it at the genus level. Keep notes on how you reached your decision. When new evidence comes to light, you can then retrace your steps and reassess.