I have a parsley and a chervil bolting right now, and both have flower stalks covered in black aphids. Strangely, they're only on the bolting plants. My first year parsley is untouched. Anyone have experience with these?
They say aphids attack only weakened and old plants. I don't know about that, since I've also seen them on plants that did not get regular watering. At any rate, I'd cut the stalks back to the ground and burn or dispose of the aphid infested parts.