Saturday, June 17, 2006

A lesser housefly, Fannia similis

Every summer I come across dozens of flies like this in M3. Although they look similar – the little brown jobs of the fly world – they have many small differences between species. In the case of this group it is particularly the bristles of the legs, head and thorax that help to define each species.

The genus Fannia has many species ranging from orange yellow to jet black. They breed in a wide range of decaying vegetable materials and other substrates and present the entomologist with that fascination of subtle variations on a theme that one often encounters with wildlife and, indeed, many other areas. Stamp collectors, for example, often pay large sums of money for stamps with minor imperfections or variations and there are many sought after forms of our ordinary, non-commemorative British postage stamp (the Machin definitive).

This is the sixth Fannia species that I have recorded in the Square Metre.

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