• Key characteristics
  • Biology
  • Impacts
  • Control
  • Further information

  • Currently only found in Nelson where an eradication attempt is underway
  • Potential to spread throughout New Zealand
  • Pest of all brassica crops, and also found on nasturtiums.
  • Butterflies look similar to cabbage white butterfly, but are 1.5 to 2 times bigger
  • Eggs are small and yellow, and are laid in clusters of 30-100 on top or bottom of leaf
  • Caterpillars have yellow and black markings, and feed together in clusters.

  • Discovered in Nelson in May 2010 and currently (December 2013) the target of an eradication attempt
  • Adult butterflies are strong fliers, so could spread outside Nelson
  • They fly on warm sunny days from early spring to late autumn
  • Females lay eggs in batches of 30-100 on brassica leaves, and can lay up to 500 eggs in their lifetime
  • Caterpillars feed in groups, often stripping all the leaves from a plant before dispersing to fresh plants
  • Young small caterpillars are yellow with shiny black heads, then they develop black spots as they get older. Larger caterpillars are speckled grey-green and black with three yellow lines along their body and lots of pale hairs. Mature caterpillars are about 5 cm long
  • Mature caterpillars crawl away from the plants and spin their cocoons in vertical surfaces such as walls, fences and tree trunks.
  • In Nelson there are 3-4 generations per year.

  • Great white butterflies feed on all brassicas
  • Feeding damage reduces yields and stock avoid grazing infested plants
  • Scouting the crop will allow detection of eggs and caterpillars.

  • Two insect biological control agents, the parasitic wasps Cotesia glomerata and Pteromalus puparum, attack great white butterfly in Nelson and should help to reduce its populations
  • No insecticides are registered for use against giant white butterfly but those used against the common small white butterfly may provide control
  • Great white butterfly should be reported to assist the eradication program
  • Phone the Ministry for Primary Industries hotline 0800 80 99 66.