Protected speargrass weevil population to swell

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DOC biodiversity ranger Brent Tandy observes a speargrass weevil on the sharp spines of a speargrass plant. Photo: Andrew Morrison/DOC.

22 December 2006

Protected speargrass weevil population set to swell

A rescue mission for threatened speargrass weevils from Wellington’s south coast has paid off with a population now established on Mana Island.

Over recent months, 32 weevils threatened by habitat loss and pest animals have been plucked from the razor sharp spines of speargrass by Conservation staff and volunteers from Friends of Mana Island and relocated on Mana Island, a DOC managed sanctuary off Wellington’s west coast which is free of mammalian predators.

DOC Poneke Area ranger Andrew Morrison said the number of weevils gathered from the south coast had exceeded all expectations.

“It’s fantastic to find enough weevils to establish an insurance population of these unique insects away from the threats of rodents, pigs and goats.”

It is hoped that weevils from a thriving Mana Island population can repopulate Wellington’s south coast once pest animal numbers are reduced. Speargrass weevils are one of Wellington’s rarest native animals. Most are found in the South Island, on the eastern side of the Southern Alps. But on the North Island they are restricted to this one small population, which is also New Zealand’s only coastal population of the species.

Mr Morrison likened searching for the weevils on the south coast to looking for “hay in a needle stack” because of the savage spines of speargrass plants and the fact that so few weevils are left in the area.

“But it was well worth the effort involved to see them settling in so well to their safe new environment.”

The new population on Mana Island will be monitored by DOC staff and volunteers to check for breeding and distribution.

ENDS

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