[HilaryG]

I have clouds of tiny white butterflies? all over my brassica, esp the redbor kale. What are they? Do I need to take action? They don't appear to be doing any harm at the moment!  Thanks

[DD.]

Whitefly.

More of a nuisance than anything.

They secret a sweet substance called honeydew on which grows a sooty mold.

You can spray them, hoover them off, or wait for a good frost.

Just wash your produce in salty water first, that'll get rid of hangers on.

[8doubles]

Sounds like whitefly which can be a curse on kale,  you end up with more fly than veg. A pain to get rid of as they lurk under the leaves.

[pushrod]

I think that spraying with soapy water kills the adults. Can always blast them with a water spray to dislodge them and try and wash off the "honeydew" DD mentioned.

[peterjf]

soapy water or spray with bug off