Longhorn beetles are a very popular group. The family includes some of Britain’s most spectacular beetles and there are many even more wonderful species abroad. They were the second family of beetles I got interested in after the ground beetles (Carabidae). But whereas you can find a decent range of carabid species in pretty much any habitat at any time of year, longhorn beetles are too few and far between to be anyone’s sole interest. These are predominantly beetles that develop in wood, with adults active only during the spring and summer. There seem to be exceptions to every rule with beetles and so it is with longhorns: two British species develop in the stems of umbellifers (Agapanthia villosoviridescens in Hogweed, and Phytoecia cylindrica in Bur-chervil, Cow-parsley and Wild Carrot).
All the longhorns that develop in wood are regarded as saproxylic beetles. And though there are some species that are truly dependent on decaying wood, there are others which could equally be regarded as phytophagous, i.e. feeding on living plant tissues. Together with the jewel beetles, they share the ability to feed on wood that is not yet decaying; they have gut symbionts that are capable of digesting lignin and/or cellulose. So in a similar way to the ambrosia bark beetles (such as the Dutch Elm disease carriers), longhorns are species that initiate the processes of decay and decomposition of trees and shrubs. In practical terms for the coleopterist in the field, this means you should be targeting early-stage saproxylic habitats for longhorns, e.g. trees or branches where the leaves are still attached but starting to turn brown.
Martin Rejzek’s chapter on the Cerambycidae in A Coleopterist’s Handbook (4th edition) is brilliant: a revolutionary improvement in our knowledge of British longhorn ecology, particularly of the immature stages.
Identifying longhorns is pretty straightforward using Andrew Duff’s excellent pair of papers in British Wildlife (vol. 18, number 6 (August 2007) and vol. 19, number 1 (October 2007)) with excellent illustrations by Richard Lewington. Both are still in stock as back issues and available for only £4.00 each.
Since Andrew’s papers, one or two more species have been discovered in Britain and “Leiopus nebulosus” has been split into L. nebulosus sensu stricto and L. linnei.
Semanotus russicus: found breeding in a Berkshire garden in 2007 (Mendel and Barclay, 2008).
Deilus fugax: I’ve heard it mentioned but I know nothing about it.
Leiopus nebulosus s.s. and L. linnei: split by Wallin et al. (2009). Males and females are identifiable using this excellent and detailed paper: the abstract can be viewed for free here but a subscription to Zootaxa is required to download the full paper. Or you could ask around.
Beetles which develop in wood are frequently transported as accidental passengers in timber, wooden furniture or wooden packaging. To identify such strays, the Cerambycidae website by Michael Hoscovek and Martin Rezjek would be a good starting point, with photos of most, if not all, of the Western Palaearctic species.
Every species included in Andrew’s ID papers has an English name, something which I applaud. However, Andrew didn’t mention that most of these names were invented by him. Many coleopterists have yet to adopt these English names, and some never will. So don’t be surprised if you talk about Black-and-yellow Longhorn Beetle and get blank stares from people who know it as Rutpela maculata. For the foreseeable future, anyone who wants to use the English names and be understood correctly should also give scientific names as well.
Martin Rejzek, now based in Norwich, started with the Czech fauna, and has gone on to become an expert on the Cerambycidae of the Western Palaearctic. He runs the British national recording scheme and can be contacted via the BRC website.
The Provisional atlas of the longhorn beetles of Britain (Twinn and Harding, 1999) is now available as a free PDF download. But it is not an Atlas that has aged very well and the maps on the NBN Gateway are more comprehensive.
Mendel. H. and Barclay, M. (2008). Semanotus russicus (Fabricius, 1776) (Cerambycidae) breeding in Britain. The Coleopterist, 17, 1 – 4.
Twinn, P.F.G. and Harding, P.T. (1999). Provisional atlas of the longhorn beetles (Coleoptera, Cerambycidae) of Britain. Huntingdon: Biological Records Centre.
Wallin, H., Nylander, U. and Kvamme, T. (2009). Two sibling species of Leiopus Audinet-Serville, 1835 (Coleoptera: Cerambycidae) from Europe: L. nebulosus (Linnaeus, 1758) and L. linnei sp. nov. Zootaxa, 2010: 31 – 45. [abstract online here]