On Jan 20, 2010, kennedyh from Churchill, Victoria Australia (Zone 10a) wrote:
I photographed this tiny moth by accident ( it was in the picture with another larger moth). It is only 6mm long and I was surprised to learn that it is a major pest species worldwide. One of its names is Cabbage Moth and it is a major pest of all the varieties of cabbage, including broccoli, sprouts, kale etc.
It probably originates in Europe, but is now know as a pest all over the world including America and Australia. It apparently carries out mass migrations which have helped its world-wide spread.
Finding it in Morwell National Park, attracted to a light, was surprising. The Park in Victoria, Australia does not grow cabbages, although there are some weeds in the cabbage family around, but not in that part of the park. There is farm land just a little to the West, so maybe that is where they occur in quantity.