A butterfly species introduced to New Zealand five years ago arrived on the Hibiscus Coast this month to assist in the fight against an invasive plant pest.
Seventy Honshu white admiral butterflies were released at Whangaparaoa Golf Club on March 1, to the immense relief of Hibiscus Coast Forest & Bird member Peter Pearce, who says he has been waging a losing battle against large quantities of Japanese honeysuckle.
The honeysuckle is a garden plant that has become a huge problem in bush areas, as it is a vine that spreads rapidly.
Peter contacted Auckland Council’s biosecurity division a year ago after finding out about the butterfly, which is being used elsewhere in the country to control the spread of honeysuckle without the need for pesticides or the hard work of manual removal of the vines.
“It is not possible to use toxic sprays in the gully area of the golf club, as it is near a stream and the sprays would also kill native species, such as nikau, which are being overrun by the honeysuckle,” Peter says. “We are also hoping that the butterflies will spread to the surrounding community where there are also infestations of this weed.”
The caterpillars were introduced to New Zealand in 2014 following extensive work by Landcare Research. The Environmental Protection Authority approved the release after research showed that the caterpillars would not feed on other plants. This species has not been used as a biocontrol agent anywhere else in the world, and is the first of what is expected to be a range of agents released to attack Japanese honeysuckle in New Zealand.
The Whangaparaoa butterfly release was attended by Peter, along with members of Council’s biosecurity team, representatives of the golf club, local Monarch butterfly breeder Graham Beeson and his wife Fay, and Hibiscus Coast Forest & Bird treasurer Stephanie Dixon.
The butterflies were reluctant to leave their box, but were eventually placed on an abundant supply of honeysuckle.