I think you want to say cabbage butterfly. There is a difference between butterfly and moth.
In day time when you have whitish butterfly hovering over your plants, it is called a cabbage butterfly, moths are generally active during night.
To control it you can use DERRIS DUST (active ingredient: 5g/kg rotenone) or if you have small area you can cover it with bird netting to act as a physical barrier between plant and cabbage butterfly.
The moth which attack cabbage plants is diamond back moth but the control is same.
FACT: Adult stages are harmless but they lay eggs on the plants which later turn into caterpillar and enjoy your crop