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This is where I post various musings about wildlife and ecology, observations of interesting species (often invertebrates)
and bits of research that grab my attention. As well as blogging, I undertake professional ecological & wildlife surveys
covering invertebrates, plants, birds, reptiles, amphibians and some mammals, plus habitat assessment and management
. I don't work on planning applications/for developers. The pages on the right will tell you more about my work,
main interests and key projects, and you can follow my academic work here.

Monday, 17 January 2011

Pattern variation in Rutpela maculata in a local woodland

Rutpela maculata (previously Strangalia maculata) is a widespread and fairly common species of longhorn beetle (Cerambycidae) in England and Wales, sometimes known as the black-and-yellow longhorn. The pattern is well known to be variable, but typically consists of four more-or-less broken black bands on the otherwise yellow elytra. The 'usual' pattern (i.e. the one that tends to be illustrated in books) is shown below.

'Typical' R. maculata, courtesy of Galerie du Monde des insectes
However, last summer, while walking in local woodland (Stoke Park Woods, Hampshire, UK), on sweet chestnut foliage I saw a specimen that definitely did not conform to this pattern. The photo below (apologies for the poor focus) shows the much greater amount of black with fusing of bands.

The 'Stoke Park' R. maculata showing a greater than usual amount of black.

Although still clearly recognisable as R. maculata (the shape, leg colour and spines etc. are unchanged), it is worth noting the superficial similarity to other banded longhorn species such as Judolia sexmaculata, the three-banded longhorn.

J. sexmaculata, courtesy of 'Cerambyx'

Despite the superficial similarity, it is clear that the patterns are different with J. sexmaculata having differently shaped spots/bands, generally with more angular edges. It also has more rounded elytral tips and tapers less towards the rear as well as having darker legs than R. maculata. So, a good example (I think) of pattern variability in a common species, although not one that should cause too much confusion. For more about British Cerambycidae, including identification by pictures, a good place to start is the following two-parter in British Wildlife: enjoy!

Duff, A. (2007). Longhorn beetles: Part 1. British Wildlife 18(6): 406 - 414.
Duff, A. (2007). Longhorn beetles: Part 2. British Wildlife 19(1): 35 - 43.

1 comment:

  1. These lepturine cerambycids really can be a variable lot - variation is the fuel of evolution!