Any plant consistently attacked should be planted at a different time, preventative measures taken or not planted at all.
Large pieces of eggshell can be scattered amongst cabbages to confuse the Cabbage white butterfly. The theory goes that it will mistake the eggshells for other butterflies and leave the area looking for less populated plants to lay its eggs on.
Attract small insect-eating birds by providing safe nest sites and a constant supply of water.
Insect predators of caterpillars include: assassin bugs; tachinid flies; paper wasps, which chew up caterpillars and feed them to their larvae; lacewings and ladybirds eat moth eggs; tiny trichogramma wasps parasitise moth eggs; other tiny wasps like
Apanteles sp. parasitise the caterpillar, the wasp larvae feed on non-essential parts of the caterpillar.
Garlic spray can be used as a repellent and to kill caterpillars.
Dipel
contains
Bacillus thuringiensis, or Bt for short