First of all, what are reed beetles? They are the subfamily Donaciinae within the Chrysomelidae (leaf beetles), and are medium-sized (5-12 mm), fairly elongate and often metallic beetles found generally on waterside vegetation. In Britian there are 21 species within three genera - Donacia, Macroplea and Plateumaris. However, despite being of a fair size with charismatic colouration, some are highly variable in colour whilst true morphological differences between species can be slight. This, coupled with a lack of accurate illustrated keys, meant that there was considerable confusion regarding identification of this group in Britain prior to the publication of keys by Menzies & Cox (1996), and subsequently (currently undergoing revision) Hubble (2010). Knowledge of the group was also greatly enhanced by the publication of an illustrated and annotated atlas (Cox 2007). A visit to an old Hampshire water-meadow in late May 2001 produced many sightings of several species and it is these that are presented and discussed here.
|The River Itchen as it runs through the water-meadows.|
|A pair of reed beetles on Iris pseudacorus|
|A green reed beetle on a yellow iris flower|
|A blue reed beetle running along the stem of an umbellifer|
|Dorsal view of a blue reed beetle|
|A metallic-green reed beetle|
So, what of the rest? Well, the following pictures are the 'best of the rest' - generally unidentified, or only identified tentatively, due to my unwillingness on this occasion to collect them - some jewels are best left unmined and I had no urge to add them to an entomological collection. Instead they are here to show the varied nature of these splendid beetles. Enjoy!
|A reed beetle on a curled iris petal - unidentified, but the pronotal groove and faint elytral green-gold banding suggests Donacia marginata as the usually clearer marking are variable and may be reduced or absent.|
|Two images of another charismatic specimen - this time with a reddish tinge on the pronotum and front third or so of the elytra.|
|Two specimens of what I think are the same species with shiny, almost sparkling, reddish-brown to dark brownish-green elytra.|
|And last, but not least - the Donaciinae - feel the love!|
- Cox, M.L. (2007). Atlas of the Seed and Leaf Beetles of Britain and Ireland. Pisces, Newbury.
- Hubble, D. (2010). Keys to the Adults of Seed and Leaf Beetles of the British Isles (Coleoptera: Bruchidae, Orsodacnidae, Megalopodidae and Chrysomelidae). Test Version. FSC, Preston Montford.
- Menzies, I.S. & Cox, M.L. (1996). Notes on the natural history, distribution and identification of British reed beetles. British Journal of Entomology and Natural History 9: 137-162.
For excellent online coverage of the European Donaciinae, including many photos of prepared specimens, see here.