By 3 News online staff
The school holiday hunting season for the great white butterfly in the Nelson area has netted 134 of the pests for the Department of Conservation.
DOC put a $10 bounty on their heads before the school holidays began two weeks ago and encouraged children and adults to help keep the population down during the butterfly breeding season.
Department staff themselves have also netted 165 butterflies, 4650 caterpillars and 532 egg clusters since late August.
The programme is an attempt to eradicate the butterfly from the Nelson-Tasman area and stop it spreading to other parts of the country.
Project manager Bruce Vander Lee says the butterfly poses a "major threat" to endangered native cresses, brassica crop including cabbage and broccoli and crops to feed cattle and sheep.
Mr Vander Lee says 337 individuals or groups, both adults and children brought in the butterflies to the department's office over the holiday period.
It was difficult for people to tell the difference between the great white butterflies and the small white butterflies, which are also a pest, he says.
"So not surprisingly a lot more of the more numerous small white butterflies were handed in – 3417 in total.
"We wanted to see them though to check they were not great white butterflies and those catching them have gone in a draw to win spot prizes," he says.
Nelson householders also reported findings of caterpillars and eggs to DOC staff, who have carried out more than 5100 garden searches so far.
Mr Vander Lee says it is too early in the eradication programme to fully assess the impact the school holiday project has had.
The school holiday programme coincided with the peak period for butterflies emerging from pupae.
The butterfly's spring breeding burst is likely to continue for a few months, so DOC is still asking for the Nelson community's help to find caterpillars and eggs and to kill the butterflies.
However, the bounty is no longer in place.
Mr Vander Lee says the reward was only set for a limited time to avoid people breeding butterflies to get the bounty.
Caterpillars and eggs should be reported to the Ministry for Primary Industries hotline on 0800 809966.