Great white butterflies lay their eggs on the leaves of plants that contain mustard oil. The caterpillars feed on the leaves and use the mustard oil to produce their own chemical compounds that give them an unpleasant flavour. This flavour together with their distinctive coloration gives them some protection from potential predators.
Mustard oils are found in many plants in the Mustard family (Brassicaceae) but also in some plants in other families too. The mustard family includes many common vegetables, some important crops, some common weeds and 79 species of New Zealand native cresses.
Image gallery
Below are some of the plants favoured by the great white butterfly on which its caterpillars and eggs can be found. Some of these plants may be growing wild in your garden without you even knowing.
Brassica vegetables
- Arugula
- Bok choy - Pak choy
- Broccoli
- Brussels sprouts
- Cabbage
- Cauliflower
- Choho
- Chou mouellier
- Horseradish
- Kale including Cavolo nero
- Kohlrabi
- Komatsuna
- Mibuna
- Misome
- Mizuna
- Mustard
- Mustard lettuce
- Radish
- Rape
- Rocket
- Swede
- Turnip
- Watercress
Brassica plants usually found in flower gardens
- Colewort also known as greater sea kale / Crambe cordifolia
- Honesty also known as money plant / Lunaria annua
- Nasturtium / Tropaeolum majus
- Stock / Matthiola incana and Matthiola longipetala
- Wallflower / Erysimum cheiri
- Spider plant or spider flower / Cleome hassleriana
Wild brassica
- Hedge mustard / Sisymbrium officinale
- Shepherds purse / Capsella bursa-pastoris
- Wild radish / Raphanus raphanistrum
- Wild turnip / Brassica rapa ssp sylvestris
New Zealand Weeds - Massey University website
Native brassica found in Nelson Tasman
- Coastal peppercress / Nau / Lepidium banksii (nationally critical)
- Cooks scurvy grass / Nau / Lepidium oleraceum (nationally endangered)
- Marsh yellow cress / Poniu / Rorippa palustris
- Matangoa / Rorippa divaricata (nationally vulnerable)
- Native bittercresses - several species of Cardamine