Do you mean blackfly? Spray for aphids if you do, but don't spray open flowers, and spray in the evening when the bees aren't working.

NO!!!!

If they are indeed tiny beetle-like insects (rather than fly-like) and are on the flowers rather than the foliage then they are pollen beetles, which, as their names suggests, feed on pollen. They were amongst the first of all insect groups to evolve - well before the flying insects - and are the principle pollinators of "primative" flowers like Magnolia. They are very much goodies, not baddies. :-)

Once the oil seed rape is harvested, all these horrible pollen beetles get displaced and come to our gardens.
I'd agree with Ilex that that is what they are. They only affect the appearance of the flowers.