Garden searches for the great white butterfly will be scaled down over winter as butterfly activity dwindles. No infestations have been found so far in autumn but DOC is still asking residents to still keep a lookout for the pest.
DOC Great White Butterfly Project Manager Michael Shepherd said no great white butterfly detections for nearly five months, since 16 December, didn’t necessarily mean all the butterflies had been wiped out.
“Autumn is a peak time for butterfly breeding so not finding any is promising but there could still be butterflies around that have escaped detection. Our butterfly eradication programme continues to ensure we eliminate the entire population.”
She says although the search will be scaled down there is no guarantee the butterfly has been irradiated. She says DOC plan to carry on searches near the end of winter where the population could rise again.
“We’re asking the public to still keep a look out over winter as some caterpillars and eggs may
turn up on winter brassica vegetable crops such as cabbages, broccoli, kale and cauliflowers. Some caterpillars stay dormant as pupae through winter and the great white butterfly’s greyish-white or pale green pupae might be found on fences and other structures.”
DOC is also asking gardeners to consider planting winter cover crops that don’t attract the pest butterfly. Many people plant mustard, but this is a brassica and great white butterfly host plant. DOC suggests instead planting cereal crops such as rye, oats and barley instead. Other alternatives are plants from the pea family such as lucerne and broad beans.
Anyone finding great white butterflies, their eggs, caterpillars or pupae, is asked to report it by calling the Ministry for Primary Industries hotline on 0800 80 99 66. DOC staff will then respond.