I have black fly on my Sambuca and a few on the Broad Beans although this doesn't affect the bean pods or the beans themselves. I've given up with spraying, never use chemicals as this n turn affects to the birds and actually, the ants and ladybirds are doing a grand job of eliminating the black fly. Everything has to live and eat somewhere, why interfere with the balance of nature?
Are You Finding the Hot Weather is Making you Short Tempered?
I haven't had them before but I am so determined to try and get rid of them. They have been doing so well too.