DOC saluted for eradication
"This was the first eradication of an unwanted butterfly population in the world.'' DOC deputy director-general operations Mike Slater
The ‘‘world-leading’’ eradication of an unwanted butterfly population in the Nelson region has earned the Department of Conservation top honours at the New Zealand Biosecurity Awards.
DOC was presented on Wednesday night with the Supreme, and Government, awards for its work in eradicating the great white butterfly from New Zealand.
DOC deputy director-general operations Mike Slater said the awards were ‘‘a tribute to the skills, innovation and determination of the DOC staff and others involved’’.
He said the multi-agency programme was led over three to five years to eradicate the butterfly from the Nelson-tasman region where it was first found in 2010.
‘‘This was the first eradication of an unwanted butterfly population in the world and it prevented the great white butterfly becoming a major pest in New Zealand. The programme ended last year after no sign of the pest for 18 months.
‘‘Our rangers carried out more than 263,000 searches of more than 29,000 properties to find and remove the butterfly and its eggs, caterpillars and pupae,’’ Slater said.
The great white butterfly is a destructive pest of brassica plants in numerous countries across Europe and western Asia.
Its caterpillars feed voraciously in groups on host plants, rapidly reducing them to a skeleton.
According to DOC the butterfly would have spread throughout New Zealand if not stopped, posing a threat to 79 native cress species, of which 57 were at risk of extinction, and ravaging commercial vegetable crops and farm forage crops.
An independent assessment for DOC estimated that if the butterfly became widespread it could cost the country $43 million to $133 million a year in spraying crops and protecting native cresses.