Invisible in the blink of an eye, they fold themselves along the thin edges of vision, with all the stealth of a clever magician. Even in the mesh cage I have built, they always find a place to sneak in and shimmy. And today, as I stooped to plant the seedlings out in moist black compost, one of them had the nerve to flirt with my unhappy cheek.
It was tempting to eat these tender broccoli leaves myself, stir fry them in a little soy sauce and garlic, savour them before caterpillars have any chance to start chewing the crop that will feed us through next Spring. They have refined taste, these butterflies, homing their offspring in amongst one of the most delicious and expensive vegetables around.
In the tough arena of growing vegetables without having all the creatures of the world eating them first, and avoiding one spray kills all known pests, I discovered that venomously repeating the word brassicas is very cathartic. I stomped home, still with my frown.