You can easily identify some of the species using a microscope without the need for dissection. For example, all the species of snakeflies (Raphidioptera) from the British Isles can be differentiated from each other by their wing venation. The alderflies (Megaloptera), both males and females, can be identified from their genitalia without dissection; this is also the case with male scorpionflies (Mecoptera). Lacewings (Neuroptera), for example Conwentzia (Coniopterygidae) species, male Sisyra (Sisyridae) species, green lacewings (Chrysopidae), some brown lacewings (Hemerobiidae), and antlions (Myrmeleontidae), can be identified using a microscope without dissection. Some species however, require dissection or clearing of their abdomens (using 10% potassium hydroxide – see Plant 1997 for details of this method) to view diagnostic characters.
The best published resource for the identification of British Isles lacewings and allies is:
Plant, C. W. 1997. A key to the adults of British lacewings and their allies (Neuroptera, Megaloptera, Raphidioptera and Mecoptera). Field Studies Council, AIDGAP guide, 90pp.
This is an excellent resource on identifying the species from the British Isles. It has information on the habitats, plant associations and distribution of the insects, in addition to how to preserve specimens, and how to prepare specimens to view the diagnostic characters of the genitalia. The illustrated identification key covers all species from the British Isles, with the exceptions of a few species recorded after publication. To identify these extra species see:
Sympherobius klapaleki – Whittington, A. 1998. Sympherobius klapaleki Zeleny (Neur.: Hemerobiidae) new to Britain. Entomologist’s Record and Journal of Variation, 110, 288-289.
Nineta pallida and Nineta inpunctata – Canard et al. 2014. On the occurrence of Nineta pallida (Schneider, 1846) and N. inpunctata (Reuter, 1894) in the British Isles and remarks on these rare green lacewings (Neu.: Chrysopidae). Entomologist’s Record and Journal of Variation, 126, 97-108.
Peyerimhoffina gracilis – Donato, J. et al., 2001. Peyerimhoffina gracilis (Schneider, 1851) (Neur.: Chrysopidae): A green lacewing new to Britain. Entomologist’s Record and Journal of Variation, 113, 131-135.
Myrmeleon formicarius – Cook, D. et al. 2013. Myrmeleon formicarius (L. 1767) (Neur.: Myrmeleontidae): An ant-lion new to Britain. Entomologist’s Record and Journal of Variation, 125, 174-178.
For Freshwater species (alderflies (Megaloptera: Sialidae) and sponge flies (Neuroptera: Sisyridae) Elliot’s book is a great resource for identification as well as ecological information:
Elliott, J. M. 1996. British freshwater Megaloptera and Neuroptera: a key with ecological notes. Freshwater Biological Association Scientific Publication, Volume 54, pages: 1-69.
For all European species see:
Aspöck, H.; Aspöck, U.; Hölzel, H.; Rausch, H. 1980. Die Neuropteren Europas. 2 vols. Goecke and Evers, Krefeld, West Germany. Volume 1: 495 pp.; Volume 2: 355 pp.
These books are in German and unfortunately very expensive. However, even if you cannot read German, the books have excellent images showing diagnostic features as well as distribution maps. This is an essential resource to consult if you have a specimen that does not quite fit with Plant’s 1997 key, as you may have a first record of a mainland European species in the British Isles (if this is the case the specimen should be retained and sent for confirmation).
General guide:
Brock, P.D. 2021, Britain’s Insects: A Field Guide to the Insects of Great Britain and Ireland, Wild Guides, 608pp
This has a well-illustrated guide to identifying some species of lacewings, snakeflies, alderflies and mecopterans found in Britain.
Older resources:
Killington’s 1936/7 monograph on British Neuroptera has a wealth of information on the lacewings found in Britain, some of which is still relevant, however care should to be taken as it was published over 80 years ago and therefore some information is now out of date. The same is true of Fraser’s 1959 Key, which also has some errors within. In both of these, and other older works, some of the names of species have changed, to check the current names visit the Synonymic Checklist section.
Webinars:
Tanyptera Trust webinars – two parts on British Isles Lacewing and Allies identification
Websites:
The Recording Scheme website here has identification guides for the British Isles species click the links below to be directed to the relevant sections:
Mecoptera (Scorpionflies and Snow Fleas)
Other excellent websites that are useful for identification are:
Nettvinger, mudderfluer og kamelhalsfluer i Norge og Norden (Lacewings, Alderflies and Snakeflies in Norway and the Nordic countries) – This site is not in English, however it has excellent images to help identification and Norway and the Nordic countries share a lot of the same species as the British Isles.
NatureSpot – Has excellent images and information on Lacewings and their Allies from Leicestershire and Rutland.
Apple wildlife – Has excellent images and information on identification of Lacewings and their Allies.
Can’t identify your specimen
If you are struggling to identify your specimen, you can send them to:
Colin W. Plant
14 West Road
Bishops Stortford
Hertfordshire
CM23 3QP
Make sure to say whether you want the specimen returned after identification – if you do make sure postage stamps or arrangements for payment for return postage is included.