I have a plum tree in my backyard (perth) and the plums on it are just
starting to ripen. I haven't sprayed it for fruit fly as last year we
did not have many and I did not need to and its much nicer that way I
think

Alas this year the fruit fly has already started to get it and the
fruits not quite ripe yet but I think it will only be a week or so
more.

Is it too late to spray the tree for fruit fly now?

Darryn