Just sitting having dinner by my Winter Gap kale seedlings. A wasp
visited and paid a lot of attention to the seedlings, mainly the
undersides of the leaves. It did check out my plate but did not stay
long. Another (or the same, it is hard to tell) wasp visited the
seedlings (same behaviour), and ignored my plate.

During the day (i.e. before about six o'clock) I have quite a few white
butterflies visiting the seedlings. I usually spend some time in the
evenings rubbing eggs (yellow and white, single and multiple) off the
seedlings.

Are wasps looking for eggs too? If not, then what? They do not show
any interest in the leaves per se.

Bill