Hello,

I am growing some beans and they have patches of black flies on. The
beans seem to be growing regardless. Should I be worried or is it just
a cosmetic problem? I would think that if the flies are drinking sap
or something, they are using energy that the plant would otherwise use
to grow, so perhaps I would be best rid of them?

I have tried washing up liquid but it doesn't seem to have done
anything. I looked on a couple of bottles of insecticides but they all
say not to use when in flower because they will poison the bees. Of
course, the beans are in flower so does that mean I cannot use
anything stronger now? Was I supposed to spray them earlier in the
season?

Thanks,
Stephen

PS please see my other bean question.