Butterflies fly by day and moths by night ...? No, not true. I am sure no butterflies fly by night but there are a number of moths that fly by day including this one, the silver Y (Autographa gamma), which is quite happy to fly by day or by night.
All the silver Y moths we see here are immigrants from the warmer climate of Southern Europe. In some years they can be abundant everywhere and I remember giving up after counting to a hundred one morning in my moth trap and I still had many more to go!
Not often found at rest, usually there is a fluttering of wings, but when they do settle the silver Y marking on the wings is quite distinctive. There are golden Y moths too, but not usually seen during the day unless disturbed.
The silver Y does lay eggs on every kind of low vegetation and the larva do hatch and become adults later in the summer boosting numbers but they cannot survive our winters.