Normal people call them cabbage butterflies. I don’t know if that’s their Latin name, but “brassicaceae” is right because they don’t just attack cabbage but also cabbage relatives (broccoli and brussel sprouts, in my case).
In Denver, I threw in the towel and just didn’t plant any after two summers of hosting larvae farms. Here, I planted them to see if the butterflies are an issue. Judging by the white butterflies hovering about the plants, they are.
Now I need to decide: Do I want home-grown broccoli enough to engage in chemical warfare against the butterflies? This is not an environmental question. It’s a question of whether or not I want to bother with it.
It wasn’t an environmental question even before I looked it up, but now I _really_ don’t care:
The primary biological poison used to control cabbage butterfly larvae is Bacillus thuringiensis (Bt), specifically the strain kurstaki (Btk). This bacterium acts as a stomach poison; when ingested by actively feeding caterpillars, it becomes activated in their alkaline gut and produces toxins that are lethal to them, causing death within 3-4 days.
Marked Up 