27th June 2012

A very humid night (17C) produced a flurry of moths in the walled garden trap. Nothing rare, but a few nice ones. The Peppered Moth is particularly interesting as it is often cited as an example of evolution in action. The story goes that there are two common forms of the moth; the "typical" form below and an all-black or melanic form. Given a clean environment with lichen-covered trees etc the typical form has a distinct advantage over the black form when it comes to camouflage on a tree trunk. However, with the sooty environment of the Industrial Revolution, the black form has the advantage when blending in with blackened tree trunks. And this is the position we were in 40 years ago with melanics forming 80% of the Peppered Moth catches at Keele. However, things have improved greatly since then and the environment is much cleaner. So much so that over the past two years I have not caught a black Peppered Moth - a complete reversal!
Peppered Moth

Small Angleshades

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