The Department of Conservation is asking for continued support from the Nelson Tasman community for a concerted push in coming months to ensure the pest great white butterfly is wiped out.
No great white butterfly infestations have been detected for more than 6 months, since December, despite intensive searching by DOC rangers over summer and autumn but some of the population could have remained undetected.
DOC’s great white butterfly eradication team is now preparing to quash any potential spring butterfly breeding spurt. Searches of gardens in Nelson city and into Richmond are being made in July to identify likely host plant hotspots for butterfly breeding. Checks for infestations will then be focussed on these hotspots.
DOC Great White Butterfly Project Manager Michael Shepherd said the eradication programme was now on the “home straight” in mopping up what might remain of the pest butterfly population.
“We’re nearly there in eradicating the pest butterfly population. What is found in August as butterflies emerge from pupae will give a good indication of what is left of the butterfly population.
“We need the public’s help in ensuring no great white butterflies, caterpillars or eggs escape detection to suppress their spring breeding and eliminate the last of the population.
“We are asking residents to catch and keep any great white butterflies if they can and to report any great white butterflies, eggs, caterpillars or pupae to the Ministry for Primary Industries hotline 0800 80 99 66. DOC rangers will then respond.”
The DOC-led effort to eradicate the great white butterfly was launched in November 2012 to clear it from Nelson Tasman, where it is only found, and to stop it spreading to the rest of New Zealand. The butterfly poses a threat to endangered native cresses and to commercial and home brassica crops, including dairy and sheep forage crops.