Gardens contain a bewildering array of insects, spiders, mites, millipedes, centipedes, woodlice, slugs and snails. A minority causes damage to plants but most are beneficial or at least neutral in their impact on gardens.

Apart from the obviously beneficial insects, such as ladybirds, hoverflies and bees, insects and other invertebrates contribute to gardens in other ways. They provide food for birds, bats, hedgehogs, shrews, frogs, toads and newts, slow-worms and lizards.

They help break down and recycle dung, carrion and dead plant material. They pollinate flowers – essential for most fruits and some vegetables – and they add to the wildlife interest of gardens.

Most people will have seen what to them is an unusual bug in their garden and wondered what it is and what it does. Identification is not always easy because of the large number of species likely to be found in gardens.

In many cases accurate identification is only possible after careful examination of the specimen under a microscope by someone who is familiar with that group of creatures. However many common garden insects and other invertebrates can be identified to a general type without special equipment or knowledge. The following are useful sources of information.

Settle down with a good book

Some of the books in this list may be out of print but may be available from public libraries or second hand booksellers. This is not a complete list of identification guides but picks out those that are well illustrated.

General identification books

Complete British Insects by M. Chinery, pub. Harper Collins 2005 ISBN 0007179669

A Colour Atlas of Pests of Ornamental Trees, Shrubs and Flowers by D.V. Alford, pub. Timber Press 2003 ISBN 0881925616

The Oxford Book of Insects by J. Burton, pub. Oxford University Press 1979 ISBN
0199100055

Collins Field Guide: Insects of Britain & Northern Europe 3rd edition by M. Chinery, pub. Harper Collins 1993 ISBN 9780002199186

Terrestrial Invertebrates by S. Tilling, an AIDGAP key, pub. Field Studies Council 1987 ISBN 1851531875

A Key to the Major Groups of Freshwater Invertebrates by P. Croft, an AIDGAP key, pub. Field Studies Council 1986 ISBN 1851531816

Insects on Nettles by B.N.K. Davis, pub. Richmond Publishing 1991 ISBN 0855462833

Aphid Predators by G.E. Rotheray, pub. Richmond Publishing 1989 ISBN 0855462698

Insects on Cabbages and Oil Seed Rape by W. D. J. Kirk, pub. Richmond Publishing 1992 ISBN 0855462876

Animals Under Logs and Stones by C. P. Wheater & H. J. Read, pub. Richmond Publishing 1996 ISBN 0855463015

Animals of the Surface Film [insects and other invertebrates on the surface of ponds etc.] by M. Guthrie, pub. Richmond Publishing 1989 ISBN 085546271X

Insects on Cherry Trees by S. R. Leather & K. P. Bland, pub. Richmond Publishing 1999 ISBN 0855463112

British Plant Galls – Identification of Galls on Plants and Fungi by M. Redfern & P. Shirley, an AIDGAP key, pub. Field Studies Council 2002 ISBN 1851532145

Butterflies and Moths (Lepidoptera)

Britain’s Butterflies by D. Tomlinson & R. Still, pub. WILDGuides Ltd 2002 ISBN 1903657016

The Colour Identification Guide to Moths of the British Isles, 2nd edition, by B. Skinner, pub. Viking/Penguin 1998 ISBN 067087978

The Colour Identification Guide to Caterpillars of the British Isles by J. Porter pub. Viking/Penguin 1997 ISBN 0670875090

British Pyralid Moths by B. Goater, pub. Harley Books 1986 ISBN 0946589089

Dragonflies/Damselflies (Odonata)

The Dragonflies of Great Britain and Ireland by C. O. Hammond, pub. Curwen Press 1977 ISBN 0902068067

Dragonflies by P. L. Miller, pub. Richmond Publishing 1995 ISBN 085546299X

Grasshoppers/Crickets/Cockroaches/Earwigs (Orthoptera, Dictyoptera and Dermaptera)

Grasshoppers and Allied Insects of Great Britain and Ireland by J. A. Marshall & E. C. M. Haes, pub. Harley Books 1988 ISBN 0946589135

Grasshoppers [also includes crickets] by V. K. Brown, pub. Richmond Publishing 1990 ISBN 0855462779

Mayflies (Ephemeroptera)

Mayflies by J. Harker, pub. Richmond Publishing 1989 ISBN 0855462736

True Bugs (Hemiptera)

Land & Water Bugs of the British Isles by T. R. E. Southwood & D. Leston, pub. F. Warne 1959. Now available as a 2005 facsimile edition, pub. Pisces Conservation ISBN 1904690319. Also available as a CD-ROM.

A Photographic Guide to Shieldbugs and Squashbugs of the British Isles by M. Evans & R. Edmonson, pub. Wild Guide UK 2005 ISBN 0954950607

Ants/Bees/Wasps (Hymenoptera)

Ants by G. J. Skinner & G. W. Allen, pub. Richmond Publishing 1996 ISBN 0855463058

Bumblebees by O. E. Prys-Jones & S. A. Corbet, pub. Richmond Publishing 1991 ISBN 0855462574

Bumblebees by T. Benton, pub. Collins 2006 ISBN 0007174500

Field Guide to the Bumblebees of Great Britain & Ireland by M. Edwards & M. Jenner, pub. Ocelli Ltd 2005 ISBN 0954971302

Solitary Wasps by P. F. Yeo & S. A. Corbet, pub. Richmond Publishing 1995 ISBN 0855462957

Beetles (Coleoptera)

A Field Guide in Colour to Beetles by K. W. Harde, pub. Octopus Books 1984 ISBN 0706419375

Ground Beetles by T. G. Forsythe, pub. Richmond Publishing 1987 ISBN 0855462639

Ladybirds by M. Majerus & P. Kearns, pub. Richmond Publishing 1989 ISBN 0855462671
Weevils by M. G. Morris, pub. Richmond Publishing 1991 ISBN 0855462817

Longhorn Beetles of the British Isles by N. Hickin, pub. Shire Books 1987 ISBN 0852638973

Flies (Diptera)

British Hoverflies by A. E. Stubbs & S. Falk, pub. British Entomological & Natural History Society, 2nd edition, 2002 ISBN 1899935053

British Soldierflies and Their Allies [also includes horse flies, robber flies, bee flies, snipe flies, stiletto flies and others], by A. E. Stubbs & M. Drake, pub. British Entomological & Natural History Society 2001 ISBN 1899935045

Mosquitoes by K. R. Snow, pub. Richmond Publishing 1990 ISBN 0855462752

Blowflies by Z. Erzinclioglu, pub. Richmond Publishing 1996 ISBN 0855463031

Woodlice (Crustacea)

Woodlice of Britain and Ireland by S. Hopkin, an AIDGAP key, pub. Field Studies Council 1991 ISBN 1851532048

Slugs and Snails (Mollusca)

A Field Guide to the Land Snails of Britain and North-west Europe [also includes slugs] by M. P. Kerney & R. A. D. Cameron, pub. Collins 1979 ISBN 000219676X

Land Snails in the British Isles by R. Cameron & G. Riley, an AIDGAP key, pub. Field Studies Council 2003 ISBN 9781851538904

Spiders (Arachnida)

The Country Life Guide to Spiders of Britain and Northern Europe by D. Jones, pub. Country Life Books 1983 ISBN 0600356655

Colour identification charts

The Field Studies Council has published a series of fold-out charts on laminated paper for the identification of a wide range of animals and plants.    

Those specifically covering insects and other invertebrate animals are:-

Guide to Butterflies of Britain by J. Bebbington & R. Lewington, pub. 1998

Guide to Hawkmoths of the British Isles by J. Bebbington & R. Lewington, pub. 2008

Guide to Day-flying Moths of Britain by R. Lewington, pub. 2006

A Guide to Caterpillars of Butterflies of Britain and Ireland by R. Lewington & J. Bebbington, pub. 2002

Guide to Dragonflies and Damselflies of Britain by S. Brooks & R. Askew, pub. 1999

Guide to British Grasshoppers and Allied Insects by J. Marshall & D. Ovenden, pub. 1999

Guide to the Shieldbugs of the British Isles by B. Nau, pub. 2004

Guide to the Ladybirds of the British Isles by M. Majerus, H. Roy, R. Ware & C. Shields, pub. 2006

Guide to Bees of Britain by C. O’Toole & C. Shields, pub. 2007

A Guide to House and Garden Spiders by L. Bee & J. Bebbington, pub. 2002

The Woodlouse Name Trail by S. Hopkin, pub. 2003

Useful links

The following websites mainly belong to special interest groups, some with useful picture galleries, but there are many individuals with sites too.  Some sites can contacted for help with identifications of digital images. It may be possible to be put in contact with someone who is prepared to examine and identify actual specimens, as many insects and other invertebrates can't be identified in more than general terms from photographs alone.

Butterfly Conservation [also covers moths]
Ian Kimber’s website with more than 3600 pictures of over 1600 species
British Dragonfly Society
Land Bug and Water Bug Recording Schemes (Heteroptera)
Bees, Ants & Wasps Recording Society
Bumblebee Conservation Trust
The Symphyta Forum (sawflies)
The Coleopterist (beetles)
British Ladybirds
Balfour-Browne Club (water beetles)
Dipterists’ Forum (true flies)
British and foreign flies
UK Hoverflies Forum
Conchological Society of Great Britain and Ireland (slugs and snails)
British Arachnological Society (spiders)
British Myriapod and Isopod Group (centipedes, millipedes and woodlice)
British Plant Gall Society
Leaf miners

Ask an entomologist

You may know someone who can identify insects and/or other invertebrate animals found in the garden, either through your own circle of friends, or by being given a contact address. While it is possible to name distinctive insects from photographs, drawings or descriptions, it is usually necessary to see a sample of the undamaged creature if it is to be properly identified.

If you are sending samples to someone you do not know personally, do check first that the person is prepared to help you. Do not overburden that person with large numbers of specimens or frequent enquiries. Many people who do insect identification do so in their spare time, so be patient if the answer does not come back by return of post.

Always include an email address or SAE for the reply, plus extra postage if you want the specimens and/or the container returned. Send your specimens, either alive or dead (but not squashed) in a stout container capable of travelling through the postal system. Give some background information about where and when the specimen was found, what plant it was feeding/found on and any other information that may help with the identification.

Organisations who may be able to help with identifications

The Royal Horticultural Society, Members’ Advisory Service, RHS Garden, Wisley, Woking, Surrey, GU23 6QB. NB The identification/advisory service offered by the RHS is for members only.

The Natural History Museum, Cromwell Road, London SW7 5BD

London Wildlife Trust, Skyline House, 200 Union Street, London SE1 0LW

Compiled by Andrew Halstead, Principal Entomologist, RHS Garden, Wisley.