Why not on red?

[Monika]

I did a caterpillar patrol today on all our brassicas. Unfortunately, I didn't find any to pick but did notice some damage and the very obvious thing is that only the purely green plants are affected (green cabbage, caulis, calabrese etc) and NONE of the red cabbages, red kale and slightly coloured kales. There must be something in the red colouring that cabbage whites don't lay their eggs on them. Interesting.

[donedigging]

I grow red salad bowel for this reason, mostly left alone by slugs and snails,
Whereas icebergs don't stand a chance.
Perhaps it has something to do with an instinct that red means danger..
Just a guess, I'm sure someone with far more wisdom than me will provide an answer for you

[Nature's Babe]

Red kale is pretty pest free too.

[Colin Miles]

My theory is that the green caterpillars are more visible on red brassicas but that assumes butterflies and birds seeing colours the same way as we do. Or it could be smell?

Weather so wet here that only the occasional white. Fortunately plenty of Meadow Brown, Gatekeepers and Burnet moths in the meadows, even a Large Skipper - but no blues.