Platypus threaten living cultural treasures
Heavy beetle attack to this Kopi tree indicated
by large amounts of fresh frass (borer dust).
No, this is not about another cultural faux pas by Australia, but the effect our own native pinhole beetle (Platypus apicalis) is having on treasured Moriori tree carvings on the Chatham Islands.
The Moriori were a distinctive group among Polynesian people, evolving a unique and non-violent culture on the Chathams. They were the only Polynesian people known to have carved living trees. Although it is unclear just how many carvings were made, what is apparent is the rapid rate of loss over the last 100 years, either through land clearance or individual tree mortality. Even as recently as the 1940s and 50s there were possibly over a thousand carvings remaining, whereas today only several hundred still exist.
In recent times, efforts have been made to protect reserves containing the carved Kopi trees (Corynocarpus laevigatus) from cattle and sheep, but unfortunately for many of the mature trees, damage had already been done.
On a recent visit to the Chathams to conduct surveillance for new pests, staff from SPS Biosecurity visited the significant Hapupu Reserve and noted that several of the large carved trees had active Platypus attack.
Platypus beetles are initially attracted to volatile compounds given off by stressed trees. If the ‘host’ is found to be suitable, the first arrivals emit an aggregating pheromone triggering a mass attack. Usually at this point, the tree’s natural defences fail, succumbing to a combination of wood boring and fungi. The latter enter via the galleries the beetles have created in the wood.
Although a natural forest process, the pinhole beetle attack highlights the fragility of these very precious trees.
Article reproduced with permission from Paul Bradbury, SPS Biosecurity Ltd,
paul.bradbury@spsbiota.co.nz.
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Page last updated: 12 June 2008