I have been watching this little fellow for a few days now.
Then I heard a discussion about her on my ABC radio.
Blows in from the inland on the easterly winds, lays eggs near aphids (I have some on my parsley) and the larvae eat the aphids!
She is only about 4 mm long and posed a bit of a photographic challenge because of her speed.
Here she is resting, or egg laying, on a tomato leaf.