[cc]

As per earlier post.
Lots of what appear to be eggs but no caterpillars. I do find cabbage whites under the netting BUT the eggs don't look like cabbage white eggs???
The holes in the pictures are not caused by the beasties. But there are holes in the kales which may be caused by them.
See pictures.

[cc]

From Google "Certain aphid species cover their eggs with wax to make them distasteful to predators."
Which turns them grey.
But can't find out which aphid?

[AnneB]

They look like mealy cabbage aphids to me.
Inspect regularly and squish by hand!

[mumofstig]

Sometimes a good squirt of diluted washingup liquid washes off the waxy coating enough to kill'em - but rubber gloves and squishing does the job just as well.
Next year perhaps invest in some enviromesh (quite reasonable on the online store beginning with A...) But you do have to make sure there are no gaps round the bottom.
enviromesh

[cc]

Got excellent insect mesh but I was using it to keep the birds off. Put a better effort in to block out insects now.
Thanks