Saturday, 11 February 2012

A moth!

This is the first moth I have been able to photograph since around November.

The Pale Brindled Beauty - Phigalia pilosaria - normally flies from January to March, but early specimens can be found in December.

Pale Brindled Beauty - Phigalia pilosaria

There are two main colour variants: the first - like mine - is mostly pale, but specimens found in the centre of large cities tend to be almost uniformly dark grey. This is a clear example of selective mutation, where species increase their chances of survival by favouring colour forms that best match their surroundings. Evolution is generally thought to take place over many thousands of years, but it's clear that adaptation can take place in a few hundred years where situations demand. Clean air (like mine, which is washed most days) = pale specimens: polluted air (as found in large cities, with associated sooty deposits) = dark specimens. There are quite a few moths where this variation in colour distribution is the norm. In each case, the pale form is found on my patch.

The specimen in my photograph is clearly a male, since the female - in common with many of the winter moths - is flightless.

1 comment:

Toffeeapple said...

I didn't know that some female moths are flightless!