Silver Y

Silver Y, Autographa gamma gamma.  Caught on Hayes Common,  1 July 2012.

Some moths don't survive our winter temperatures, but are still common.  How is that?  Because they fly here every year from the continent. (Later: I have since been told that there has not been much immigration this year, and the ones we are seeing have probably bred here.) 

This is one of them.  It's called the Silver Y, and this is how it gets its name:

Silver Y, Autographa gamma gamma.  Caught on Hayes Common,  1 July 2012.

There are many of them to be found in meadow grass just now, flying by day and easily disturbed by walkers.  I saw one on Farthing Downs a few days ago, and yesterday I disturbed several of them on Hayes Common, five minutes from my house.  So today I went out with a little plastic tube and caught one to bring back for a photo.  It's not very easy to get a good clear shot in the meadow, because they rest near the ground and there are always grass stems in the way.  Normally they will fly off when you get close, and they will certainly leave if you try to brush nearby grass stems aside.  So to catch one you will probably have to chase after them several times, and not lose sight of where they come to rest.  Perhaps they get weary.  I managed to catch the third one I found. 

I encouraged this one to rest by cooling it in the fridge, but even so, after only thirty seconds or so on this piece of bark, it started to vibrate its wings to warm up, and very soon it took off.  It's vibrating its wings in the top photo.

They breed fast, and are not fussy about what they eat, and there should be plenty around now until the frost gets them.  And a few do occasionally survive the frost.  But it's the inward migration that makes them common.