Black fly - LOTS!

Did say in another aphids post on here, that I've not had hardly any blackfly this year.
I spoke with the two allotments near me and they have seen very little and same with my immediate neighbours.
My Dad eight miles north of me has had plenty, but no more than previous years. He grows his much earlier than me and over winters a few rows. He does spray them (I do tell him off for that, not organic), but does pick out the tops.
Its always said that being near the coast, we get less blackfly.
I always use a soap and water spray early on on the broad beans growth and a refresh every week, pick out the tops once the first flowers appear and keep picking them off.
We have always had plenty of ladybirds round here too.