Buprestidae – Jewel Beetles
A fabulous family of beetles. There are only 14 species in 5 genera on the 2008 British checklist but two further species have been discovered since. This is a large family of beetles abroad, with many spectacular representatives, especially in warmer climates.
Anthaxia nitidula: collected in the New Forest by Philip Harwood on 4.vii.1934. Now extinct in Britain.
Possibly our most spectacular British jewel beetle is Anthaxia nitidula, only known from the New Forest and last seen there in 1954. What could have changed in the New Forest to cause the extinction of such a beetle? Apparently the final blow was over-zealous scrub clearance at Balmer Lawn in the late 1950s.
Most of the world’s jewel beetles are saproxylics and can thus be transported around the world in timber or in wooden furniture, packing materials, etc. A further nine non-native species are already listed in the 2008 checklist as “non-established introductions” and that list will probably continue to grow.
There are two genera of jewel beetles in Britain which mine leaves or stems (Trachys and Aphanisticus) and three genera of saproxylic jewel beetles (Anthaxia, Melanophila and Agrilus). The saproxylic species are very unusual amongst British saproxylic beetles. Firstly, Melanophila acuminata is our only saproxylic beetle which is strongly associated with fire-damaged wood: it is a rare and seemingly declining non-native species on lowland heathland. The six Agrilus species (and perhaps also both Anthaxia species) feed on wood at the very start of the decay process. The vast majority of saproxylic beetles cannot digest lignin or cellulose, the main constituents of wood; they can only derive nutrition from wood after fungi have begun the decay process. However, Agrilus species are able to steal a march on the fungi and feed on fresh wood, albeit they seem to be restricted to trunks or branches that are already stressed by drought, shading or physical damage. Perhaps they need bacterial decay to be underway before they can feed? If not, they must have specialist gut symbionts that can allow them to derive nutrition from lignin and/or cellulose. The only other saproxylics that can feed on living (or at least non-decaying) wood like this are many of the longhorn beetles (Cerambycidae). It is debatable whether these jewels and longhorns are saproxylic or phytophagous; beetles frequently confound attempts to categorise them and the answer here is, of course, they are both! The ambrosia bark-beetles (Scolytinae) are also pioneers of the wood-decay succession but they carry their ambrosia fungi with them to help turn living wood into food.
Finding jewel beetles is not easy. The commonest species in my experience is Agrilus laticollis though even that is Nationally Scarce (Nb). It can be beaten from the outer branches of oaks from late May to early September but particularly during June and July. The same applies to Agrilus angustulus though it is less frequent. Hawthorn Jewel Beetle Agrilus sinuatus is best recorded by looking for exit-holes in hawthorn (see my article on this species). Similarly, Agrilus biguttatus is best recorded by looking for D-shaped exit-holes in the trunks of mature oaks.
Agrilus laticornis © Alan Outen
I have found Trachys troglodytes and T. scrobiculatus several times by suction-sampling Devil’s-bit Scabious Succisa pratensis and Ground-ivy Glechoma hederacea respectively. See my article on Trachys troglodytes here. Aphanisticus pusillus is also a fairly predictable species, if you target your suction-samples at Glaucous Sedge Carex flacca on calcareous grasslands in southern Britain. I have also found it by grubbing at the roots of Sand Sedge Carex arenaria in the Brecks. In the tray, these are all beetles which tuck their legs and antennae in and lie still for a long time; it’s easy to overlook them as just seeds.
With the recent growth in use of suction-samplers, records of all three of these species must have increased dramatically. So it is surprising that nobody has yet found Aphanisticus emarginatus by suction-sampling. It hasn’t been seen in Britain since 1951 (Longmoor Camp, Liphook, North Hampshire). Other old records come from North Devon, Dorset, the Isle of Wight (Parkhurst) and Berkshire. Target Jointed Rush Juncus articulatus if you want to be the one to rediscover it. It is a more slender, elongate species than A. pusillus.
Aphanisticus pusillus (L) and emarginatus (R)
Trachys minuta is another rare species. Its larvae develop on willows/ sallows Salix spp. and Hornbeam Carpinus betulus (according to Levey (1977)). Adults are best found by beating the branches and foliage of these hosts, although David Appleton found it repeatedly and in numbers on hazel branches at Botley Wood, Hampshire (Appleton, 2004).
For identification, I start with Brian Levey’s (1977) Royal Entomological Society Handbook (out of print). Since Levey’s Handbook, four species have been added to the British list:
- Anthaxia quadripunctata added by Jon Cooter (1992),
- Agrilus cuprescens added by Peter Hodge (2010) (also mentioned earlier in the report of the 2008 Annual Exhibition of the BENHS),
- Agrilus cyanescens added by Peter Hodge (2010) (also mentioned earlier in the report of the 2008 Annual Exhibition of the BENHS),
- Agrilus sulcicollis added by Trevor James (1994).
Bílý (1982) is the English-language key which best covers the British fauna (excluding only Agrilus sinuatus) but the papers by Trevor James and Peter Hodge are also invaluable for identification of Agrilus. Brian Levey is drafting a new key to the enlarged British fauna of eight Agrilus species which I look forward to seeing. Meanwhile, for anyone who can read French, all the British species of Agrilus are covered by Théry’s (1942) Faune de France volume which can be downloaded for free. Bílý (1982) and Théry (1942) both include A. cuprescens under the name A. aurichalceus but otherwise the names agree with the Duff (2008) checklist.
There are distribution maps and species accounts in the provisional atlas (Alexander, 2003) (except Anthaxia quadripunctata, Agrilus cuprescens and Agrilus cyanescens). Order from the BRC website. Keith Alexander would be glad to receive records of jewel beetles for the national Cantharoidea & Buprestoidea Recording Scheme: details here.
Acknowledgement
Thanks to Keith Alexander for comments and advice on this webpage.
References
Alexander, K.N.A. (2003). Provisional atlas of the Cantharoidea and Buprestoidea (Coleoptera) of Britain and Ireland. Huntingdon: Biological Records Centre.
Appleton, D. (2004). Scarcer Coleoptera in Hampshire and Isle of Wight 1964 – 2001. The Coleopterist, 13: 41 – 80.
Bílý, S. (1982). The Buprestidae (Coleoptera) of Fennoscandia and Denmark. Fauna entomologica scandinavica, vol. 10. Klampenborg: Scandinavian Science Press.
Cooter, J. (1992). Anthaxia quadripunctata (Linnaeus, 1758) (Coleoptera: Buprestidae) in England: an enigma. Entomologist’s Gazette, 43: 75.
Hodge, P.J. (2010). Agrilus cuprescens (Ménétriés, 1832) and A. cyanescens Ratzeburg, 1837 (Buprestidae) established in Britain. The Coleopterist, 18: 85 – 88.
James, T.J. (1994). Agrilus sulcicollis Lacordaire (Buprestidae): a jewel beetle new to Britain. The Coleopterist, 3: 33 – 35.
Levey, B. (1977). Coleoptera: Buprestidae. Handbooks for the identification of British insects, vol. 5, part 1 (b). London: Royal Entomological Society.
Théry, A. (1942). Coléoptères buprestides. Faune de France, 41. Paris: Librairie de la Faculte des Sciences. [available for download from here]
4 Responses “Buprestidae – Jewel Beetles”
Very helpful Mark, thankyou, particularly the excellent illus of A. pusillus and A. emarginatus. I have found T. troglodytes commonly, T. scrobiculatus less commonly, and A. pusillus rarely, by pitfall trapping in chalk grassland where the foodplants are present.
Thanks Michael – appreciated.
I cant seem to find B. Levey’s Coleoptera: Buprestidae Handbook on the RES website. Is it still available?
Rik, I should have said, it is out of print I’m afraid. I suggest you ask RES for permission to photocopy it (or ask them to send you a photocopy).